Moparts

A-727 help

Posted By: reno340

A-727 help - 09/26/17 05:51 AM

Ok, I am getting frustrated. I have been dealing with the same trouble with this transmission since day 1. It keeps leaking out of the front pump or something in behind the torque converter. I have rebuilt the transmission, put in a new torque converter, new front pump bushing and seals and I got a leak again. I had pulled the motor to rebuild it, and while it was out got another torque converter, (for more performance since I built the engine) and had a tranny shop put in another new seal and bushing in the pump. so I thought I had it fixed but I was only taking short trips across town in it. I have been driving it for a little while and thought all was welll with it. Today I took it up the highway and smoke poured out from under the car and I noticed when I drove it by a buddies house, I was leaving a trail of tranny fluid. I looked and sure enough, it is dripping out of the front again. Another complaint is that I have had to run the car in neutral to pump fluid to get the car to back out of the garage. I only have to do it once that day. Does anyone know what is happening?
I really need help here.
Posted By: B5 Bee

Re: A-727 help - 09/26/17 06:11 AM

A leaky shift shaft seal is very common. I've had to change several over the years. There is a tool to change it without dropping the pan. It may not be your problem since the leaky shift shaft seals I've had only leak when the car has sat unused for a period of time.

The O-ring on the dipstick tube is a possibility and easy to change. I'd check that first.
Posted By: Dave Hall

Re: A-727 help - 09/26/17 06:50 AM

Pretty common on the neutral thing. They don't pump fluid in park. I'm dealing with the same leak from the front seal right now so please post back what you find out. What happens on mine is that it drips and fills up the bell area and when I hit the brakes it dumps and gets on the exhaust.
Posted By: RapidRobert

Re: A-727 help - 09/26/17 07:20 AM

my front pump seal has a minor leak also & I took care on installing the new seal when I put this (727) trans in. I may have distorted it a bit tho I was careful just because of this exact potential. I packed the garter spring with vaseline all to no avail. my next one I might have to locate the seal driver that goes into the seal ID then you drive it in.
Posted By: Motor Mayhem

Re: A-727 help - 09/26/17 02:37 PM

One thing to check for is a restricted oil cooler circuit. This can cause fluid to be forced out of the vent.
Posted By: 451Mopar

Re: A-727 help - 09/26/17 03:38 PM

re-locate vent to rear of transmission.
Check dip-stick tube. I had one that was cracked where the "O"-ring fits.
Sonnax lube regulated pressure regulator valve.
http://www.sonnax.com/parts/1842-lube-regulated-pressure-regulator-valve
Posted By: 469runner

Re: A-727 help - 09/26/17 04:31 PM

Front pump retaining bolt washers. Front pump seal. Converter hub seal. Vent. Dipstick tube. These are all areas that can leak out of the front.
Posted By: JohnRR

Re: A-727 help - 09/26/17 04:43 PM

Originally Posted By Dave Hall
Pretty common on the neutral thing. They don't pump fluid in park.


Incorrect, it pumps fluid in park just not at the rate it does in neutral or in gears.

Transgo has a replacement manual valve, it's included with their shift kits, that allows more fluid flow in park.

There are more things than the seal that can leak up front. Every bolt has a seal washer under it, a lot of times they do not get replaced. The square cut o ring around the outside of the the pump body can also be a leak point, especially if the surface it seals against is damaged or it gets damaged on install. Same goes for the bore the seal is installed in.
Posted By: John_Kunkel

Re: A-727 help - 09/27/17 12:24 AM


Be sure the dipstick is reading correctly and you're not overfilling it. The FULL mark on the dipstick should be about 1/4" above the ledge where the dipstick tube enters the case.
Posted By: reno340

Re: A-727 help - 09/27/17 01:50 AM

the thing that seems to jump out at me is the idea of fluid going out the vent tube. It only really did this when I ran it up the highway. I had been driving it on the streets and secondary roads for about a month and it really didn't leak this badly. I did put in a new filler tube that had a locking dipstick that had a different type of grommet type of seal instead of the O-ring. The gaskets and the O ring around the pump are new and carefully put in. I had a tranny shop install the bushing and shaft seal for the Transmission pump. seems like the higher RPM's made the fluid come out. (3.55's with 14 inch tires at 70 MPH) Relocating the vent?
How do I do that? Can it be done with the transmission in the car? Ughhhhh!! I'm getting tired of pulling out this transmission.

451 Mopar
So, is the Sonex lube pressure valve the fix for the leak or for the drainback?
Posted By: RapidRobert

Re: A-727 help - 09/27/17 03:36 AM

Originally Posted By John_Kunkel

Be sure the dipstick is reading correctly and you're not overfilling it. The FULL mark on the dipstick should be about 1/4" above the ledge where the dipstick tube enters the case.
John does that apply the same on a 904?
Posted By: pjc360

Re: A-727 help - 09/27/17 03:54 AM

Originally Posted By John_Kunkel

Be sure the dipstick is reading correctly and you're not overfilling it. The FULL mark on the dipstick should be about 1/4" above the ledge where the dipstick tube enters the case.


I agree with john, few years back I had a transmission shop re-build the A-518 that's in my 91 short bed 4x4 dodge truck and they decided to give me a new dip stick tube that went behind the engine instead of to the side how they normally did them.
I had the same issue, tranny fluid pouring out of the front, took the truck back cause it was under warranty.
The owner him self got involved and pulled the transmission and I called him and he said i tore the entire thing down and I have no idea why it was leaking everything is solid, and that night while he was laying in bed he remembered the dip stick tube they had swapped inn and bells went off and sure enough they had over filled it by about 2-3 qts and every time I would hit the highway it would come out.
So make sure your dip stick level is right before tearing it back out.
Posted By: Motor Mayhem

Re: A-727 help - 09/27/17 04:44 AM

Check the cooler and lines. When I built the 440 for my coronet, I had the car parked in the lot at work with the radiator out and the lines propped up to keep them from leaking. After installing the engine, all seemed fine until the first time I took it up to highway speed. It then puked at least a quart out of the vent. After verifying the fluid level (I had installed a new tube and locking stick), I finally decided to flush the lines and cooler. Found the lines plugged with small insects called cutter bees that had climbed into the lines while the motor was out. Blew out the bugs and all was well.
Posted By: RTSrunner

Re: A-727 help - 09/27/17 05:58 AM

I agree with the dipstick check as the first opion.New parts,double check fit.On another idea,is it possible there is a crack in the case or the pump?
RT
Posted By: 451Mopar

Re: A-727 help - 09/27/17 06:56 AM

I just found out that Sonnex has the pressure valve for the older transmissions. I thought it was only for the newer transmissions.
I haven't used the valve yet, but I like the design. It is to allow the fluid flow to cooler when in park, without the drain-back issue of just drilling the valve body.

I have been using the Trans-Go TF-2 shift kits, with their manual valve which seems to work good too.

When I re-located my vent, I drilled the main case when it was out of the car, but you could do the tail shaft extension too.
A Pneumatic 1/8" NPT to 1/4" push to connect tube connector, and some 1/4" Nylon Pneumatic tubing run to a higher location like the firewall worked good for me
Posted By: JohnRR

Re: A-727 help - 09/27/17 04:36 PM

You are going to have to pull the trans to relocate the vent, part of relocating the vent is the block the one in the pump housing, you can't do that with it in the car.

Did you do anything to modify the the front drum so it expels more fluid when venting? Is the plastic baffle for the vent cover intact inside the trans ? stock drum or a billet drum with a larger piston that requires the vent to be modified ?
Posted By: reno340

Re: A-727 help - 09/28/17 03:23 AM

Originally Posted By JohnRR
You are going to have to pull the trans to relocate the vent, part of relocating the vent is the block the one in the pump housing, you can't do that with it in the car.

Did you do anything to modify the the front drum so it expels more fluid when venting? Is the plastic baffle for the vent cover intact inside the trans ? stock drum or a billet drum with a larger piston that requires the vent to be modified ?


I did put in a front drum from a diesel ram but it was early enough that it fit. The valve body was also changed to a Chetah forward pattern manual valve body. I have a 2400 stall converter in it too but if pretty much feels little to no different than the old one.
Posted By: reno340

Re: A-727 help - 09/28/17 03:34 AM

Originally Posted By John_Kunkel

Be sure the dipstick is reading correctly and you're not overfilling it. The FULL mark on the dipstick should be about 1/4" above the ledge where the dipstick tube enters the case.
Is there a way that I can Measure this without pulling the dipstick tube? I hate to have to lose all of that fluid. (I have a deep aluminium pan) The dipstick and tube are an Allstar Performance 69120 dipstick and tube.
Posted By: RapidRobert

Re: A-727 help - 09/28/17 06:13 AM

if you had another tube layeing around you could check it that way (assuming they are both dead on identical) which I would think they would be.
Posted By: A727Tflite

Re: A-727 help - 09/28/17 03:43 PM

Measure the outside of the tube from the top to the top of the trans case next to he tube entry point - following the contour of the tube. Then measure the stick from the bottom of the dipstick cap that rests on the tube down the same distance you got from the first measurement. Mark the stick there.

Then warm the trans up, run it through R, low then back to N then check the fluid level.

If above the new mark drain until on the new mark you made. That should get you very close.
Posted By: JohnRR

Re: A-727 help - 09/28/17 04:56 PM

If you have a deep alum pan it should have a drain plug correct ? If so you can always drain it into a clean pan and reuse it , drop the pan and look at the dipstick when it's installed to exactly where the full line is when the stick is installed.

I know it's messy but you will know exactly where it is .
Posted By: jwb123

Re: A-727 help - 09/28/17 06:06 PM

Don't know if you have a shop near that has one, but I have seen torque converters crack, usually close to the welds where the sections go together. They make a fixture to put air pressure in the converter when it is on the bench to check for leaks. See guys chase their tails a lot before they figured it out.
Posted By: John_Kunkel

Re: A-727 help - 09/28/17 07:28 PM

Originally Posted By reno340
I have rebuilt the transmission, put in a new torque converter, new front pump bushing and seals and I got a leak again.
Posted By: reno340

Re: A-727 help - 09/28/17 07:31 PM

I did remove the lines and blew the cooler and lines out with compressed air. I lost enough tranny fluid that it touches the dipstick about 1/4 inch. It is quite a ways from the full line. In park, no leak. in neutral, if starts pouring out the bell housing. This is frustrating. I seem to keep on fixing the same stuff.
Posted By: reno340

Re: A-727 help - 09/28/17 08:02 PM

Originally Posted By reno340
Originally Posted By JohnRR
You are going to have to pull the trans to relocate the vent, part of relocating the vent is the block the one in the pump housing, you can't do that with it in the car.

Did you do anything to modify the the front drum so it expels more fluid when venting? Is the plastic baffle for the vent cover intact inside the trans ? stock drum or a billet drum with a larger piston that requires the vent to be modified ?


I did put in a front drum from a diesel ram but it was early enough that it fit. The valve body was also changed to a Chetah forward pattern manual valve body. I have a 2400 stall converter in it too but if pretty much feels little to no different than the old one.
The pump in front of the tranny is probably from the older transmission I had looked up the tranny and the numbers showed it to be from a '66 small block C body. Any ideas? Do I need a different pump? If so, from what year?
Posted By: John_Kunkel

Re: A-727 help - 09/28/17 10:20 PM


Fluid leaking from the front vent isn't endemic to the Torqueflite under normal usage, something is causing the leakage and band-aids like relocating the vent won't fix it.
Posted By: A727Tflite

Re: A-727 help - 09/28/17 10:56 PM

Two style pumps housings - vent wise. Early style used a metal shield inside and attached to the support with two of the bolts - the shield covered the actual vent passage on the inside while another metal shield was used on the converter side and attached using two of the pump to case bolts.

Later design used a plastic whistle on the inside held in place with a "nail" ( not your normal wood nail but that's what they were called ). No shield on the bell side. If you are using the early style make sure you have that tin shield on the inside.

You mention leaks in neutral - how about in drive but not moving ? Everything is stationary inside in d or r if the car is stationary. If it leaks then you likely have something more serious going on.

One other thing to look for if you take it apart again - the pump bore where the pump fits the case - check at 6 o'clock - sometimes the soft plugs in the perimeter of the pump housing can get pushed out and when the pump was removed it left deep scratches in the case bore. This was more of a problem in the 2000 - 2005 time frame on 46/47/48 transmissions but something to be aware of. In some cases the soft plug fell out - this would cause a leak at certain times depending what circuit was affected.

All else fails refer to the earlier service manuals for checking for leaks using air pressure.
We check all our Reman transmission using Uson air decay - you can do the same basic test using air pressure and snoop - soapy water sprayed on the pump to case joint and bolts, front band pivot shaft plug and the converter impeller hub.
Posted By: reno340

Re: A-727 help - 09/29/17 02:01 AM

I agree whole heartedly. I don't want a band aid fix. The more I read from the replies, the more I was convinced that I was not interested in relocating the vent. I just don't know why this thing is doing this. I had this happen when I first got the car out. I then rebuilt the tranny. I put in a new reman torque converter in it. The following year, I had the motor out for a rebuild and was going to put in a new B&M torque converter since I upgraded the motor. When I pulled it to put the new converter in, I noticed the torque converter that I put in was scarred a little where it goes into the pump. so I took out the pump and had a tranny shop put in a new seal and bushing. Everything installed smoothly. so after running it some, I thought it was ok. A couple of days ago I took it up the highway. Fluid was pouring out of the front of the bellhousing. This is frustrating as the build went smoothly and the transmission works really well. I have a manual valve body in it that gives me incredibly firm shifts.
Help!!!!
Posted By: reno340

Re: A-727 help - 09/29/17 02:04 AM

Originally Posted By Transman
Two style pumps housings - vent wise. Early style used a metal shield inside and attached to the support with two of the bolts - the shield covered the actual vent passage on the inside while another metal shield was used on the converter side and attached using two of the pump to case bolts.

Later design used a plastic whistle on the inside held in place with a "nail" ( not your normal wood nail but that's what they were called ). No shield on the bell side. If you are using the early style make sure you have that tin shield on the inside.

You mention leaks in neutral - how about in drive but not moving ? Everything is stationary inside in d or r if the car is stationary. If it leaks then you likely have something more serious going on.

One other thing to look for if you take it apart again - the pump bore where the pump fits the case - check at 6 o'clock - sometimes the soft plugs in the perimeter of the pump housing can get pushed out and when the pump was removed it left deep scratches in the case bore. This was more of a problem in the 2000 - 2005 time frame on 46/47/48 transmissions but something to be aware of. In some cases the soft plug fell out - this would cause a leak at certain times depending what circuit was affected.

All else fails refer to the earlier service manuals for checking for leaks using air pressure.
We check all our Reman transmission using Uson air decay - you can do the same basic test using air pressure and snoop - soapy water sprayed on the pump to case joint and bolts, front band pivot shaft plug and the converter impeller hub.
I have the earlier metal vent
Posted By: 451Mopar

Re: A-727 help - 09/29/17 05:53 AM

Originally Posted By reno340
Originally Posted By Transman
Two style pumps housings - vent wise. Early style used a metal shield inside and attached to the support with two of the bolts - the shield covered the actual vent passage on the inside while another metal shield was used on the converter side and attached using two of the pump to case bolts.

Later design used a plastic whistle on the inside held in place with a "nail" ( not your normal wood nail but that's what they were called ). No shield on the bell side. If you are using the early style make sure you have that tin shield on the inside.

You mention leaks in neutral - how about in drive but not moving ? Everything is stationary inside in d or r if the car is stationary. If it leaks then you likely have something more serious going on.

One other thing to look for if you take it apart again - the pump bore where the pump fits the case - check at 6 o'clock - sometimes the soft plugs in the perimeter of the pump housing can get pushed out and when the pump was removed it left deep scratches in the case bore. This was more of a problem in the 2000 - 2005 time frame on 46/47/48 transmissions but something to be aware of. In some cases the soft plug fell out - this would cause a leak at certain times depending what circuit was affected.

All else fails refer to the earlier service manuals for checking for leaks using air pressure.
We check all our Reman transmission using Uson air decay - you can do the same basic test using air pressure and snoop - soapy water sprayed on the pump to case joint and bolts, front band pivot shaft plug and the converter impeller hub.
I have the earlier metal vent


The earlier pump with same year support should not be compatible with the later diesel drum unless the support was changed to a newer style?

I looked to find the cost of that Sonnax regulator valve, and they are fairly expensive. Best price I found so far was from E-Bay at about $40. Anyone know of a lower price source?
Posted By: reno340

Re: A-727 help - 09/29/17 06:31 AM

What year support are we looking at?
Posted By: reno340

Re: A-727 help - 09/29/17 06:54 AM

http://www.ebay.com/itm/A518-DODGE-CHRYS...=item1ea0cabfff
IS THIS WHAT i NEED?
Posted By: 451Mopar

Re: A-727 help - 09/29/17 07:43 AM

I believe that in 1971 and up the front drum was changed to use a wider bushing (not sure if the sealing ring spacing changed?), and the pump support for the drum was changed because of that. That is why when you said you had an early pump with later drum, it might be a mis-match in parts? The later pumps with the baffle can still puke fluid. I just tap the front vent hole with an NPT tap and put a plug it it, and re-locate the vent to the back of the case. That way I know a leak in the pump area is not coming from the vent.
If you have Carl Monroes' torque flight handbook, I think it covers the modification.

https://www.amazon.com/Torqueflite-727-Transmission-Handbook-HP1399/dp/1557883998
Posted By: A727Tflite

Re: A-727 help - 09/29/17 08:49 AM

Regarding the front drum to support bushing - there are two reaction shaft support bushing sizes from 1962 - 2008, narrow and wide. The metal seal ring spacing never changed on the wide bushing support.
I think you can install the wide bushing drum on a narrow bushing support and the unit will assemble - that is not suggested and I cannot see how that could cause a leak like the op has but who knows. Good catch.

There is absolutely no reason to change the vent location on a non-transbrake application.
Millions of vehicles without an issue. And a bunch used in racing without issue too.

I would start with the oil level verification suggested. If that doesn't produce results then time to get deeper.

The Sonnax regulator valve is not needed either. A pump with proper internal clearances will prime the system and fill the converter in a few seconds. It's a nice addition if you want to spend the money but it's not going to fix this transmission problem.
Posted By: 80fbody

Re: A-727 help - 09/29/17 01:53 PM

I'd personally pickup a good used trans and put that one under the bench. You'll waste more time in money chasing what is likely some part mismatch in the rebuild. Save it for a parts mule.
Posted By: FurryStump

Re: A-727 help - 09/29/17 04:26 PM

So there really are only six areas that can leak in the bell housing. Having eliminated the converter.
1) converter hub lip seal. Been replaced along with bushing.
2) interference fit of outside of that seal. Been replaced by two different people.
3) o-ring on perimeter of pump housing. Hasn't been checked yet.
4) pump housing bolts. No rubber washers? Don't know.
5) vent puking. Fluid level has been check in neutral while hot.
6) cracked case. Unknown.

Where in these six areas does the pressure of, or amount of fluid increase when the converter is charged?
Don't think it is the o-ring because I don't think it see's more pressure when the converter is charged. Unless line presure is leaking by the paper gasket and then the o ring. But line pressure is always present there.
Posted By: John_Kunkel

Re: A-727 help - 09/29/17 11:54 PM

Originally Posted By Transman
Regarding the front drum to support bushing - there are two reaction shaft support bushing sizes from 1962 - 2008, narrow and wide. The metal seal ring spacing never changed on the wide bushing support.
I think you can install the wide bushing drum on a narrow bushing support and the unit will assemble


The ring spacing did change to compensate for the wider bushing. Narrow bushing drum will fit on wide bushing support but ring location will be wrong. Wide bushing drum won't physically fit on narrow bushing support.

Attached picture RSsupports.jpg
Posted By: reno340

Re: A-727 help - 09/30/17 12:15 AM

Originally Posted By FurryStump
So there really are only six areas that can leak in the bell housing. Having eliminated the converter.
1) converter hub lip seal. Been replaced along with bushing.
2) interference fit of outside of that seal. Been replaced by two different people.
3) o-ring on perimeter of pump housing. Hasn't been checked yet.
4) pump housing bolts. No rubber washers? Don't know.
5) vent puking. Fluid level has been check in neutral while hot.
6) cracked case. Unknown.

Where in these six areas does the pressure of, or amount of fluid increase when the converter is charged?
Don't think it is the o-ring because I don't think it see's more pressure when the converter is charged. Unless line presure is leaking by the paper gasket and then the o ring. But line pressure is always present there.


1) correct
2) good tranny shop did it
3) brand new O Ring when I put the pump back in during the rebuild. The housing was clean and smooth and the paper gasket was new. I didn't use sealer on it but I didn't see where anyone had done it before me. The paper gasket is on right because I used a bolt with the head cut off to index it.
4) I had gotten new washers in the kit that I used but I don't remember them being rubber. Neither were the ones that were on before.
5) At this point, I lost enough fluid that the fluid barely touches the dipstick when hot and idling in neutral.
6) I didn't see any cracks. Like I said, clean and smooth around the pump.
Posted By: John_Kunkel

Re: A-727 help - 09/30/17 12:58 AM


I'm still thinking your dipstick is lying and the trans is overfull.
Posted By: 451Mopar

Re: A-727 help - 09/30/17 02:06 AM

Originally Posted By John_Kunkel
Originally Posted By Transman
Regarding the front drum to support bushing - there are two reaction shaft support bushing sizes from 1962 - 2008, narrow and wide. The metal seal ring spacing never changed on the wide bushing support.
I think you can install the wide bushing drum on a narrow bushing support and the unit will assemble


The ring spacing did change to compensate for the wider bushing. Narrow bushing drum will fit on wide bushing support but ring location will be wrong. Wide bushing drum won't physically fit on narrow bushing support.


Thanks for posting the photo. That was what I was trying to explain.

Relocating the vent is not really a band-aid, it just removes one possible source the fluid can come from in the bell housing area.
I usually only noticed small amounts of ATF that got out of the vent with high RPM runs.
If your dumping alot of fluid, then there is other problems.
Either way, the trans is going to have to be removed.
Might be able to remove the valve body and air-pressure check the trans, to see it you can hear leaking from the converter or pump housing area.
I think some of the pumps front bolt holes are open to the inside of the case, so a loose bolt (not sure how bad the leak would be if missing the sealing washer?) or stripped case threads could result in a leak, along with the plug for the front band pivot shaft.
And that is if the leak is not from the pump seals, gaskets, or converter.
Posted By: reno340

Re: A-727 help - 09/30/17 03:01 AM

which one is this? Is this the one I want? (this is the one in the car)


Attached picture support.jpg
Posted By: A727Tflite

Re: A-727 help - 09/30/17 04:17 PM

For those of you with difficulty sorting out my post - my statement was " there were no changes in ring spacing on WIDE BUSHING PUMPS".

I didn't say there were no change between the narrow and wide pump supports.

As for assembling - I said not suggested. I have seen instances where a guy installed a narrow bushing in a wide bushing drum. It will assemble -

Op - if you are having an issue determining fluid level - get a drain pan under the trans under the dipstick tube area. Remove the bolts holding the tube in. Warm the trans up and run through the gears. Shut engine off and pull the tube out and let it drain until it stops. Reinstall the tube and qualify the stick.

That's ALL the fluid you need. You still have a leak you have issues requiring leak testing.
Posted By: 451Mopar

Re: A-727 help - 09/30/17 05:14 PM

That photo is the early style pump. The question is you mentioned installing a different, later model, drum. With the later model drum you should have use the pump support from a later pump (or just a later pump assembly?) Also, you need to check the input shaft end play when changing out those parts. The fiber washer on the pump comes in various thicknesses to adjust the input shaft end play.
Posted By: reno340

Re: A-727 help - 09/30/17 06:29 PM

Originally Posted By 451Mopar
That photo is the early style pump. The question is you mentioned installing a different, later model, drum. With the later model drum you should have use the pump support from a later pump (or just a later pump assembly?) Also, you need to check the input shaft end play when changing out those parts. The fiber washer on the pump comes in various thicknesses to adjust the input shaft end play.
what years are good?
Posted By: John_Kunkel

Re: A-727 help - 09/30/17 06:56 PM


This continued dwelling on the vent isn't addressing the root problem. Either vent style will work fine with a properly configured and properly filled transmission.

Again, the FULL mark on the dipstick is about 1/4" above the ledge where the dipstick tube inserts into the case.
Posted By: RapidRobert

Re: A-727 help - 09/30/17 07:06 PM

Quote:
Again, the FULL mark on the dipstick is about 1/4" above the ledge where the dipstick tube inserts into the case.
John is that the same for a 904?
Posted By: 451Mopar

Re: A-727 help - 09/30/17 07:26 PM

I'm just trying to figure if changing the drum may have a part in the problem. Maybe excess fluid is blowing out around the drum sealing rings and coming out of the vent?
Really too many unknowns, need to just get in there and check everything.
Posted By: reno340

Re: A-727 help - 10/01/17 04:11 AM

Originally Posted By John_Kunkel

This continued dwelling on the vent isn't addressing the root problem. Either vent style will work fine with a properly configured and properly filled transmission.

Again, the FULL mark on the dipstick is about 1/4" above the ledge where the dipstick tube inserts into the case.


Trust me John, I am not ignoring your solution. Your reputation is simply unchallenged in these things. I really don't think the vent has anything to do with it either. After all, there were plenty of '66 and earlier transmissions that functioned well. I do know that one thing is that I have the wrong pump support for my application especially since I am using the later input shaft. I think the best thing to do is to address both of these issues as the possibility is that you two could both be right. We have two separate issues and they aren't necessarily mutually exclusive of each other.
Posted By: John_Kunkel

Re: A-727 help - 10/01/17 07:56 AM

Originally Posted By reno340
I do know that one thing is that I have the wrong pump support for my application especially since I am using the later input shaft.


What year support? What year input shaft?

The input shaft is functionally the same for all '67-'77....this input won't fit in a '66-earlier support. If the '78-later input is used in the '67-'77 support there will be no forward gears.
Posted By: reno340

Re: A-727 help - 10/02/17 02:08 AM

I will have to get back to you on that one
Posted By: reno340

Re: A-727 help - 10/02/17 04:55 AM

Originally Posted By John_Kunkel
Originally Posted By reno340
I do know that one thing is that I have the wrong pump support for my application especially since I am using the later input shaft.


What year support? What year input shaft?

The input shaft is functionally the same for all '67-'77....this input won't fit in a '66-earlier support. If the '78-later input is used in the '67-'77 support there will be no forward gears.


Ok, I am getting confused. I do have the earlier style support. (narrow bushing) what years are they? I am assuming that the pump is a 66 since the tranny is. What shaft fits this? when I replaced the torn up front drum and input shaft. the yard sent me the new style input shaft with the 3 sealing rings, It did not fit the tranny due to the bushing in the back being wrong. They sent me another shaft that did fit and I put it in. the pic below is from a different website but it shows the one that did not fit. The thing in the center is almost like a funny shaped washer


Attached picture rearclutch3.JPG
Posted By: reno340

Re: A-727 help - 10/02/17 05:18 AM

the one they sent that did not work also had 3 sealing rings like the one on the left. not sure what the one they gave me had. are all of the pumps interchangeable?

Attached picture inputshaftcompare.jpg
Posted By: John_Kunkel

Re: A-727 help - 10/02/17 07:52 PM


The pump assembly is comprised of several parts, the part that has to be compatible with the input shaft is the "reaction shaft support" (the part that unbolts from the main pump housing). The supports functionally* interchange from '62-'66 and '67-'77. '78 was the first year for the 3-tab thrust washer and the 3rd ring on the rear piston retainer; as you discovered, these won't fit earlier units.


* I say "functionally" because there was a change to the lube circuit in '74 but interchanging parts with earlier has little negative effect.
Posted By: reno340

Re: A-727 help - 10/05/17 04:39 AM

Originally Posted By John_Kunkel

The pump assembly is comprised of several parts, the part that has to be compatible with the input shaft is the "reaction shaft support" (the part that unbolts from the main pump housing). The supports functionally* interchange from '62-'66 and '67-'77. '78 was the first year for the 3-tab thrust washer and the 3rd ring on the rear piston retainer; as you discovered, these won't fit earlier units.


* I say "functionally" because there was a change to the lube circuit in '74 but interchanging parts with earlier has little negative effect.


Sorry it took so long to get back to you John. It took me a while to pull the tranny and take it apart. The input shaft seems to be from '67-'77 as I have only 2 sealing rings. I am assuming that the stator support needs to be the same. here are some pics

Attached picture pump5 (1024x768).jpg
Attached picture pump8.jpg
Attached picture pump1.jpg
Attached picture pump6.jpg
Posted By: John_Kunkel

Re: A-727 help - 10/05/17 07:04 PM

You've got a mismatch of parts, the support is for a narrow bushing and the drum is a '71-later wide bushing drum that somebody has installed the bushing shallow.

Belleville spring in the rear clutch is '74-later.
Posted By: reno340

Re: A-727 help - 10/06/17 08:01 AM

If I get the correct stator support complete with the pump assembly for 71-77, will it work correctly with my case?
Posted By: JohnRR

Re: A-727 help - 10/06/17 04:26 PM

Originally Posted By reno340
If I get the correct stator support complete with the pump assembly for 71-77, will it work correctly with my case?


It should there isn't big changes in the case over those years.
Posted By: reno340

Re: A-727 help - 11/05/17 07:02 PM

OK, I changed the stator, Pump bushing and seals, O rings and the washers. It still leaks. It is wet behind the torque converter clear to the top. I looked by using a camera and saw that it is all wet but that the vent is dry. Will the dye even work in this case? What dye is this and where can I get it?. Any other ideas?
Posted By: geo.

Re: A-727 help - 11/05/17 09:27 PM

Originally Posted By reno340
Originally Posted By John_Kunkel

Be sure the dipstick is reading correctly and you're not overfilling it. The FULL mark on the dipstick should be about 1/4" above the ledge where the dipstick tube enters the case.
Is there a way that I can Measure this without pulling the dipstick tube? I hate to have to lose all of that fluid. (I have a deep aluminium pan) The dipstick and tube are an Allstar Performance 69120 dipstick and tube.


Something I've wondered about, with a deep pan can you run a slightly lower amount of fluid(on the stick) since your fluid pick-up is lower too?
Posted By: geo.

Re: A-727 help - 11/05/17 09:39 PM

I haven't read your engine build-up.
Do you know if block was line bored or honed?
This will affect case alignment with the crank.
Might be worth checking.
Posted By: reno340

Re: A-727 help - 11/05/17 10:55 PM

no, just a basic build. The engine really didn't need much as the crank just needed polished and heck, the bores were only .003 out. It just needed honed enough to take the glaze out. So just a hot tank, polish the crank and a quick hone.
Posted By: reno340

Re: A-727 help - 11/06/17 03:41 AM

I never got it to full. I just got it to the point where the pump picked up the fluid and started pumping it. when it did, it started to stream out when in neutral or in gear. it's pretty bad.
Posted By: reno340

Re: A-727 help - 01/02/18 06:24 PM

UPDATE: I did finally find the culprit. My new torque converter was cracked at the base of the snout. It was so fine of a crack that I could not see it without pressure testing it. Here is a youtube video of my home made pressure tester for the torque converter.


https://www.youtube.com/watch?v=QDhz3MSemv8
Posted By: 469runner

Re: A-727 help - 01/02/18 06:40 PM

I am glad you found it. Does B&M not pressure test their converters? What a pain. I would be tempted to send it back and ask for a refund and go with another company. I've used Turbo Action and Dynamic with good results. Costs more, but I think a better quality unit.
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