That's now the 3rd time that 727 makes problems after a few miles and the 4th time I remove this transmission!

- The 1st time the TF2 spring was to strong for the servo and destroyed the rear band and servo ring in 100 miles!
I fixed it...
- The 2nd time I removed the trans to upgrade to a billet clutch retainer
I reinstalled it...
- The 3rd time that transmission broke in pieces after 2000miles, nobody here could tell me why, but the rear bearing snapring felt off and the output shaft moved freely and destroyed more or less the whole trans!

NOW I got a new race 727 built by someone with a great reputation and drove 50miles and 2 days ago I couldn't make it reverse, it was slipping A LOT before it started to move, but suddenly it worked and today I drove 5miles and then suddenly I couldn't reverse at all, you could feel the 727 engange the R but it wouldn't move, also reving up to 3000RPM didn't help, just the forward gears!
I turned the engine off, looked around, and retried. Now suddenly the R works and all forward gears don't work anymore!!! And I started to hear some noise from the trans when I look under the car!!!
What the heck is now bad?! I am really going to sell that car, 4 transmission fixes/breaks in 3000 total miles, that can't be true?!
I also checked the ATF fluid, it's just exactly at the full level...

you checked the fluid level with the car running and in nuetral ? You should probably contact the person who built the transmission, maybe it is a simple problem.

Yep, I checked with fluid in N and do have a deep pan from B&M...
When the engine is off, the fluid level is 1/2" over max, so I think that isn't the problem. Fluid is also not foamy or so, nice clear red.
I think it's not an easy problem, man, it's just so frustrating!
I know, but I can't get a hold of this person...

Ok, I retried again: Reverse still works good, front gears (1, 2 or D) have a HUGE slippage!!! When I rev to 3000RPM it starts to roll slooooowly! Can that be a bad sprag?!?! That's a new ultra bolt in sprag!!!

So, after the previous failures and "pulling", I dont see any mention of flushing or replacing the convertor...

any reason like you forgot to type it? or it's the same convertor..that held the same particles from the earlier disintegrations? The rear clip can really only come out if one of 2 things happened. It is fatigued from being over-spread from many removals and installs, or, it didnt seat in the groove, someone only thought it did. I hate to say this, I would have thought someone would have, but if the conv had the used oil in it, it had the residue in it, and that went all thru the new trans the second you fired it. ANY time a trans goes bad or has to be taken apart and large amounts of wear/damage are found, flush the convertor and lines at minimum, or if possible, replace them. I'm hoping it's something small, but a convertor with a bad stator or stator bearing will do just that..and spew crud all into the oil system. sorry...

Have you checked to make sure the tensioners are tightened on the Trans? There should be two of them, and you can roughly torque them at build, but they may need adjusted afterwards. I am not sure what their technical name is, but they are 1/4" square heads with a lock down nut. They adjust the tension on the bands. May not be it at all b/c I am no expert, but when I built my one tranny, I didn't have as many problems as you are having.

hi moper...

yeah, I forgot to mention that: I did send that converter back to Dynamic last time! It did cost me 300$ to send that, let inspect it (the cut it open) and send it back to me!!! They told me everything is fine, cleaned it and welded it again.
But I thought maybe that converter created that mess, because nobody could tell me why that snap ring felt off and why the pan was full of this black varnish. (the bands and clutches where fine, just the case was shot because the outputshaft pushed against the sprag and that sanded off the case where the sprag is, but this where aluminum pieces in the oil, NOT black varnish like I had everywhere!)
I also flushed my radiator and cooler lines with carb cleaner till just clean cleaner came out!
[Edited by Moparts - Keep it clean], everything was just fine... and now after 50 miles that thing felt apart again!

By the way, last year before the 727 broke down the oil was around 170F max. But on that day it broke down it went up to 190-200F in the pan, probably from the outputshaft rubbing on the sprag! After that it was toast!
I didn't install the new oil cooler it on this transmission yet because I was looking for fittings, BUT the oil NEVER got hotter than 150F in the deep oil pan from B&M! Our summer suxx, it's just all the time 60-70F max! So everything was keeping very cool and I thought I will install it this week before the weather gets hot.

By the way, last week, when the R didn't work the oil was cold! Today I drove 3miles and the oil was also cold when I lost first R and then all forward gears and it started to have this big slippage!

I just removed the oil pan and valve body, the oil is again full of black varnish and seems pretty dark to me. I will compair it on a white towel (how I was told) with the new oil.
The 2 bands look to have material as far as I can see from outside. Also the front cluth retainer and reverse drum don't seem to be discolored!
The builder just told me that it sounds like that trans got to hot! But [Edited by Moparts - Keep it clean], it never got over 150F and I just did cruise 50miles with it! The kickdown (lokar) cable is hooked up right and it didn't shift back nice at WOT.

Can that converter be the reason of my last 2 trans failures?! Can that converter create so much heat to destroy the oil on the way to the radiator, but the radiator cools it down fast enough so that I just got regular operating temperatures in the pan???

I just am so [Edited by Moparts - Keep it clean] frustrated! I got now money for new parts and the season just started... the last 4 years I drove that car 1-2 months, then the engine or 3 times the trans broke down

moposcar - you mean the band adjustment... that trans was build and dynoed and everything was checked before it was delivered to me. I will check the band adjustment but I don't think it's such a simple problem... but you never know, I will surely check that!

You state that it's a "race 727", does it have a manual valve body? If so, a broken sprag would prevent movement in 1 but not in 2 and 3.

The intermittent no Reverse could have been caused by a rear clutch that wasn't releasing and if that clutch has now failed there will be no forward gears.

When there was no Reverse did the car try to drive forward in Neutral?

Ugh...I cant see how the convertor could get things that hot, unless there was an oil delivery probelm like a kinked or flattened cooler line. Like John said, if that forward clutch (used in all forward gears, but located in the rear position in terms of clutch packs) stuck, it would be trashed when the rear band applied and you tried to move. Why would that happen..I couldnt tell you..John?

I mean with race that it had a ultra bolt-in sprag, billet front clutch retainer, billet servos, 4.2 lever, kevlar bands, accumulator rod and a TF-2 like AUTOMATIC valve body.

Yeah, the sprag is probably fine, no gears in forward work at all!

Yeeeees John, now that you say it, I think it did behave like that! I hooked off the column shift linkage because I first thought there is something wrong, but indeed, to me it seemed that it was going forward when in neutral at the moment the reverse wasn't working!
I tried to get reverse out of the parking but it wouldn't, but in neutral it would go forward. I am not 100% sure, but when trying this gears that's what I felt but I thought first I am in the wrong gear, although I shifted those gears many many times because I was hoping that it would suddenly work! So I think 90% sure that it was going forward in neutral... what does that mean?

But yeah, how and why can that happen on a fresh rebuild transmission???
I used by the way fresh Midland Type F ATF fluid and the fluid level was at max.

Do you have kickdown linkage hooked up and adjusted correctly?

Yes... the Lokar cable is hooked up so that at WOT I got the throttle pressure linkage full pushed.
The car was shifting at 38mph at very light throttle into 3rd gear and when pushing the throttle it would shift pretty quick to 2nd gear.
But wouldn't that toast the bands? The bands look good from outside. I also did drive as said 50miles with that car, maybe 20 full accelerations, otherwise just cruising around.

Tomorrow I will try to remove the trans and open it... from somewhere I have all this black varnish in the oil...

By the way, I did compair the fresh ATF with the used one on a white paper. The used one is a little bit darker from the varnish, but still red as the fresh one. Don't know if that means anything?

btt...

hi
do you have the proper filter extension to lower filter in the pan ?

what are your band adjustments set at ?

are you using kevlar bands front and rear ?

what is front drum steel or alu ?

what filter are you using cloth or brass screen ?

where are you testing trans temp from ?

Yes, it has an extension on the filter. As said, that transmission was build by someone with a very high reputation, I don't think there is a mistake like a missing filter extension, but you never know.
The band adjustment I didn't measure, but both seem to be tight, not loose or so. But I will measure it more accurate. The bands I think are kevlar (from outside the band material seems to be red/orange, not black...) But the varnish in the pan is all black, like a paste.
The billet front clutch retainer is steel, that trans was made for daily driving, high performance, but a driver.
So the filter is also the regular type.
The trans temp is in the pan with a pretty new Autogauge.
Here 2 pics of the filter and the oil. I droped a few drops of the bad used ATF and of fresh ATF so you can see the difference. The used one is still red, but got the dark dirt in it.
The filter is very dirty and those little black pieces I found there are not hard!!! They are soft, like rubber, like a sealing!?! What does that mean?

http://home.tiscalinet.ch/6o4o/727/

The rubber you see could be off the reverse clutch piston. You need to pull and disassemble and inspect to find the problem. I have seen guys use feeler guages to help install the piston and the feeler blade is like a knife and can ruin a seal on the install.

Pull the trans, have the converter flushed and replace the trans cooler and flush the lines!!!! You probably have contamination in the cooler/lines from the first failure and none of your transmissions have had a chance. The contaminates will build up as a thick mass in the cooler and not move until the fluid gets hot enough, then it spreads though the trans

Yeah, I also thought about the clutch piston sealing!

Thinking about all this 24h a day I just remember again:

The day I got that trans (that was 50miles ago) I exchanged the oil pan with my B&M oil pan with my temp sensor. When removing the pan I saw EXACTLY this black little pieces on the bottom of the pan like on the picture of the filter! I didn't feel them, so I don't know if they where soft or hard, but the size was the same, it wasn't just a varnish/paste like it's everywhere in the oil now. It where 3-5 little black pieces! That trans was dyno tested before I got it!
I asked the builder because I was worried when I saw that, but I was told this is normal when using Kevlar bands. Now that I saw that the bands are orange I know that this pieces didn't come off the bands! Maybe from the clutches, but the clutches I saw till now are also more orange/red than black!
Could that have been the begining of the end???

I deinstalled both cooler lines and flushed them well with carb cleaner, that stuff cleans ALL, it kills your hands too!
I also flushed the original 26" radiator from right to left till just clean carb cleaner came out and then did the same thing from left to right! I almost choked from that stuff!
I didn't and still didn't use any extra oil cooler, the weather is very cool (60-68F) and I wanted to install the cooler this week. So that can't be the problem.
I drove the car 2 weeks ago the first time with the new trans around 10miles, it hardly got warm! Then 2 days later I had this first time the reverse problem that didn't work. (the car was just running 5min and it was still pretty cool)
And few days later I drove the other 40miles without a problem. And yesterday I drove 3 miles and then reverse didn't work and at the end no forward gear worked...

Tomorrow I will try to get that transmission out and hope nobody comes up with some money in their hands wanting to buy that car! I am so d"*%"*% frustrated that I might sell all this crap!

hi
your filter looks dirty for only 50 miles ?

a lot o black junk and a lot of metal for such a short time ?

kelvar bands are not orange but dark green almost black .is rear band orange also?
kelvar may leave some dark residue after time but should not notice in only 50 miles .
you said bands seem tight ? not sure what you ment but if it is not releasing correctly and draging that will create heat quickly at band /drum surface . this can cause burning / flacking lining on band .

You do know that to adjust the bands, you tighten them to 72 inch lbs and then back them off 2- 2 1/2 turns (depending on the lever ratio). If they are tightened down and not backed off, there's your problem.

If you saw black in the pan, after the dyno test..I'll bet it had issues then. The "street" clutch discs I use are red Altos..same with the bands, but the forward clutch could have a light tan, or dark metallic grey look to them if they used stock replacement stuff. You raise the issue with the builder before it was ever installed, so his reaction (I woudl think) should be fairly supportive. good luck with it..it's amazing how an outside source can make you want to dump the car. Just walk away for a while..that helps for me...

Ok, now I got it open, you guys where right, the rear clutch retainer is totally gone!
It totally burned the clutches, the steels are also bend from the heat, the clutch retainer itself also shows heat signs! Also the beleville spring got scratches and so does also the front planetary assembly on the teeth a little bit.
BOTH sealing gaskets of the piston (inner and outter) are partly destroyed. I found parts of the piston seal in the clutches!
I just checked quickly the band adjustment with the "snug" method: front band got around 2.5 turns, rear band I got around 4 turns!!
The rear band also looks a little bit used! You can see the fine lines in the band, BUT on a few spots they are gone... this band was also used more than normal, but not burned or so! That would also explain the 4 turns of the rear band!
That transmission is supposed to have alto red eagle racing clutches and red lined bands. The rear band is solid and ORANGE and the front is flex and ORANGE! I always had black and solid front bands on my other tranmissions, why is this one flex and orange? Aren't Kevlar bands black?
Anyway, it's orange, so are the front clutches (they look like new!) and the rear clutches, as much as I can tell since they are burned up pretty bad! So this few black parts I saw in the pan BEFORE I installed this tranmission are 95% sure sealing gasket from the rear clutch retainer piston, or what do you think? Or do I have Kevlar parts?
I mean, I got the first time this reverse problem after 15miles driving and that trans never saw more than 140F!
It just makes me sick that I had to remove this trans a 4th time, the torque converter is again full of dirt (I paid last time 300$ to send that back to the USA to open it, inspect, clean, weld and send back to me), I got again back pain AND working today on the car and lowering the car on the lift I hit something and that bend me the whole lower quarter!!!!!! I mean, it's more than just a few broken parts, it just makes me sick!
I want to know WHY that happened and IF this parts I saw in the pan before I installed it could have been the piston sealing parts!
This valve body is by the way a modified (not by me!) VB that shifts stronger. Could a bad VB cause something like that?!
Otherwise the other parts look fine, the front clutch retainer also thank god! Sprag also...

Here are the pictures:

http://home.tiscalinet.ch/6o4o/727

thank you for any help guys... really appreciate that!

Judging from the pictures, the root cause of the failure was the plastic spacer ring in the rear clutch; when this spacer failed it allowed the piston to travel too far and pop out of its bore. When the piston leaves the bore the rubber lip seals expand and prevent it from returning, then the fluid pressure blows the seals apart. The lack of apply pressure causes the clutch discs to burn up. The plastic spacer ring is not a good choice for performance units, it should be replaced with an earlier steel spacer.

It also appears that there is a mismatch of parts in the rear clutch, a late piston was used with an early Belleville sppring, this might have contributed to the failure since the early Belleville is not as robust as the later version, especially when subjected to raised line pressure.

The color of the front band and clutches is red and they appear to be quality parts.

The pic shows the difference in the Belleville springs, the late type is on the left:

Thank you John...

What plastic spacer ring do you mean? There where the clutches and at the bottom the spacer ring is out of metal, as far as I know. But below the wave ring was sealing rubber, probably from the piston... or was there maybe a plastic spacer that is gone now?

Yes, the rear clutch retainer seems to be a late model (got a 3 tab washer + 2nd washer), the belleville spring is an early one, yes!

I will ask on the line pressure, but I said I want firm shifts... don't know if maybe the belleville was to weak? That would explain the scratches on it?! That the piston pushed the bellevile spring to much and it started to touch the planetary gears? Is that possible or how do you explain those scratches?

In one of the pics you have a red arrow pointing to a ragged piece, this appears to be the plastic spacer between the Belleville and the wavy snap ring, plastic was used from the early seventies on.

The pic shows the different style spacers, at right is black plastic, next is white plastric, next is continuous loop steel (the best) and far left is split steel.

I checked the ring, it's steel, not plastic! This plastic you see on the picture is just a big piece of piston seal. I then put it on the side of the piston, you can see it on the piston picture. It fits right there, so it's piston seal.

But I still have a few questions:

1. This black little pieces (0.08-0.1" long) that I found in the trans oilpan before I installed it, could those have been already piston seal or are they really from the kevlar parts? (if I have any?) I just didn't check if they where soft, but they had this size and where black. My bands&clutches are orange?
Can a 727 shift, get the right pressure, although the piston is already a little bit broken? Or how did it pass the dyno test?

2. Can the converter be the reason for this? As said, it was cut open, inspected, cleaned & welded again.

3. Can dirt in the oil be reason for this? I cleaned all lines and cooler as said. The VB filter is also supposed to hold back bigger parts, isn't it?
I mean, can dirt in the VB be the reason for that? Maybe it had a malfunction?

4. Why is the belleville spring scratched? How could this happen?

5. Why is the rear band used? (4x on the adjusting screw!) Does it have to do, that the clutches didn't release?

6. Do I have to send again that converter back to Dynamic to clean & inspect or is it enough if I fill in fresh ATF and drain it trough the drain plug on the converter?

thank you very much for all the great help!

*popp*

The Belleville spring has always been a problematic part in the 727, even when all the surrounding parts are in good condition the Belleville can be overstressed to the point that it will allow the piston to leave its bore. The early style Belleville with the longer internal "fingers" is more susceptible to failure and is iffy when used in a performance unit.

In your case it could have failed at any time after a dyno test. Debris or the converter won't cause the Belleville to fail. The Belleville and piston are scratched because they traveled past their intended limits and contacted spinning parts.

The black residue is probably a combination of ground up rubber and friction material from the burnt up rear clutch discs.

The filter should have prevented any major debris from reaching the converter, a good flushing with clean fluid would be a good idea.

The rear band appears to be in good condition, I have no clue as to why it was adjusted at 4 turns out; ask your builder.

In short, the source of this transmission failure appears to be the Belleville spring; a combination of the wrong part being used and the possibility it was already well used and the increased pressure from the shift kit mods over stressed it.

This is a great post! I took the recent TorqueFlite A-727 book out to see what it said about the Belleville spring because I don't remember anything about strength being mentioned as John Kunkel pointed out. And I was right it wasn't mentioned. But here is an excerpt of what was mentioned:

"Unlike the front clutch pack, the rear uses a Belleville spring to return the piston upon release. The Belleville spring was changed in 1974 to improve the neutral to drive shift. At the same time the height of the piston was increased. THESE PARTS DO NOT INTERCHANGE WITH PRIOR MODELS."

If John Kunkel is correct and you have a later piston and early Belleville, and since they don't interchange, could this be the reason for failure? (I know Kunkel alluded to this). Sounds like the builder may owe you another 727!

Quote:

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"Unlike the front clutch pack, the rear uses a Belleville spring to return the piston upon release. The Belleville spring was changed in 1974 to improve the neutral to drive shift. At the same time the height of the piston was increased. THESE PARTS DO NOT INTERCHANGE WITH PRIOR MODELS."

---

Sorry , but that is not true. Yes you can use the late piston with and early spring. I do it all the time. Even Chrysler in 2000 went back to the early style belleville spring on all the 46REs / 48REs transmissions. When useing a #374 late stlye piston with an early Belleville spring you can set the clearance between the piston and the spring down to .003 - .010, then set the clutch pack clearance at .030-.035 , this will keep the piston from coming out too far and still apply the clutches fully


You can NOT use a #212 early piston with an late Belleville spring, this is what the hand book should say.

I'm glad I read this. I'm rebuilding a trans this weekend and when cleaning everything I found the plastic spacer to be in bad condition. I checked the box of '66 trans parts I have and it had the steel welded spacer. The belville spring in the '66 trans seem to be lighter in weight than the later model one and it was cracked too.

Did you say you used Type F fluid, as in Ford? Aren't you supposed to use Dexron in a 727? Maybe it doesn't make any difference, but when I worked at a gas station they made a big deal about using the right stuff so I always assumed it was pretty critical.