727 Damage/Repair Advise

727 in my street toy seized up Friday. No clue doom was coming. Small blower on 440,3,600lbs touqey tire killer.
has Turbo Action RVB.
3rd has failed twice with 4 disc,hence the 5-disc this time. Has about 50 passes on it.
Changed rear gear from 3.33 to 3.73 Dana and on its 1st ride felt like the brakes were dragging in a cycle.
Headed home.
Was reluctant to back up the driveway,got the the shop put it in neutral and could push it easy???? WTH...
10 minutes later go to push it into the shop can`t budge it. Back it into shop pull wheels and then axles expecting rear has issue.
Pull driveshaft......... trans. is locked.
Pull it and strip it.
Front clutch pack burnt 5-Koleno/plate
Rear is OK
Output shaft support siezed to shaft,drum chewed up as well were it rides on support.

What fails the support? Lack of lube of course,but why?
Ate 5 disc in 50 passes?
What needs addressed for this issue?

I'm not sure why it ate the clutches but filling the cooler with trash will block the lube to the rear support. Have you been flushing or replacing the cooler after trashing the clutches prior? You should also have the converter cleaned out as the same trash will remain in there. Possibly a cumulative effect.

Hmmm,I guess that is possible. But there wasn`t "trash" in the pan just the fine dust from the clutches,no chunks....
Failure was slipping into 3rd.

I will examine that tho..thanks

There doesn't have to be chunks to block up a cooler. Slipping in to 3rd is another issue that could possibly be determined during teardown. Which I would strongly suggest.

Something is restricting the fluid returning from the cooler, clogged line, pinched line, clogged cooler. Also check the small hole just behind the brass fitting where the line enters the trans, I've seen that hole become clogged. You burnt the clutches as the trans was attempting to overcome the bearing seizing up. Are you using the factory trans cooler or are you running an aftermarket cooler?

Aftermarket cooler in front of the radiator.

When 3rd was slipping in the 1st 2 transmissions,fluid never burnt.

So what does it take to get a good hold of 3rd.??

Cope laughed when I said I had a Turbo Action and 3rd gear issues,didn`t elaborate tho.........

Low line pressure can cause slipping, also, if you've burnt clutches it would be a good idea to take the valve body apart. I've seen silt (clutch material) get into the passages in the valve body that would cause your problem. It will look like mud in there severely restricting flow. This is especially possible if you're using one of those screen type filters.

I am sorry to hear of your trouble with 1st gear.I went through 3 trans like that in 1 year 2 with a Chetah rmvb and 1 with CRT so now I am N/A for now.I busted the 3 planet A&A and froze the trans having to cut off the shell to get to a snap ring to seperate the shafts.I changed from a stacked shell trans cooer to a 10"x14" tube/fine.

Ok thanks for the replies.
Yes I am not as educated on trans. as engine stuff.
Ran 727 in my bracket car for 30+ years never an issue.
This car has an appetite for 3rd gear. I blamed in on tall gear,strong torq. and street abuse. I beat it like it owes me money.................
I shift at 4,800rpm at the track,trap at 5,000 11.0`s et. All bottom-mid power.

So the T/A RMVB`s have been the std when I started in the 80`s.
A 4 clutch high should handle that power just fine....right???

What about the driveshaft bottoming out? I have 3/4" free play. But what if its bending the front segment...just a theory.
It only goes low 11`s but from a roll with traction on the street,it is an animal . Bit of a pig at the track with 100% hook. If I took you for a ride up the valley,then you rode with me down the track you would ask whats wrong the the car BIG difference in performance.
Which is why I went with more gear..

Will check cooler flow and orfice stuff today.

Oh I forgot to say, I love your car.

Thanks

Did/made everything myself except seat covers.

Rear support galling can be the result of poor lubrication, but I've seen them gall with plenty of lube. It's a marginal design.

Best way to go is a roller support but you can't use one with an auto VB.

Is the roller support OK for street use?

I see there is a modified support available with a bushing in it?

Took the VB apart,,,,yeah ...it was dirty.
Now to get it all back together

What filter were you using.

Stock style.
Not the brass screen

Lets see what the clutch fibers look like. Hold the reaction support up to the light. Are the ring grooves square? Or are they worn tapered. Are the rings worn on the sides? How about where the reaction shaft support rings ride in the drum, worn? 4 clutch drum should function fine with a Turbo Action rmvb. Have you checked the pressure regvalve and spring? I'd be testing the resource when its backtogetherT/A arent real high 120ish.
Doug

Your valve body has damage in the same area I have circled. Is this a modification or is this wall damaged?

Flush the cooler and convertor as well after seeing inside that valve body. One other often overlooked possibility is one of the rubber hoses going to or from the cooler may have separated INSIDE, blocking fluid flow. I would replace both/all of the rubber hoses with new hose.

No,not damage. Thats the way they are made. PDF. file on T/A website clearly shows it this way. I went back and looked after you pointed it out.
Either way I will be comparing their picture to my actual part.....

Rings look good,grooves as well.
I ordered a kit with Teflon seals and a roller rear support.
Clutches? BALD
I will post some pics of them later

Okay, That must be a Turbo Action mod for the reverse pattern, just wondering about the looks of that wall.

Clutch pictures.
Rear shows some slip,but not failed

Looking at your valve body, you have the part throttle kickdown (PTK) module attached. It is a small casting piggy backed to the side of the valve body opposite side of the gear selector/manual valve. The Cheetah RMVB should not have that PTK attached. Look at the Turbo Action website under instructions and look for 17156 Upper Valve Body Assembly. You would need 3 short screws to delete the PTK module.

Of course check the Turbo Action model number on the valve body top plate 4 or 6 screws. Should be etched in: 17156-XXAAAA, XX is the year and AAAA is the serial # extension. If you don't have a 17156, verify the number on the website and/or call Paul Forte at TA.

Also, I would carefully check your clutch clearances upon reassembly. Direct clutches should be around 0.015" per friction disc. 4 clutches would need about 0.060" clearance and 5 would need 0.075". The forward clutches should be about 0.028" - 0.035" MAX total. I use the RAYBESTOS TAN waffle clutches in the direct and grayish RAYBESTOS clutches in the forward drum. No Kolene steels.

I would recommend a 2 spring front servo with a 4.2 band lever. Red solid backed kickdown band, not Kevlar. As mentioned before, double check your reaction shaft support sealing rings. Teflon are best. Also replace the drum bushing and check for wear in the drum sealing ring area. I would use 12 springs in the direct drum. Remove the accumulator spring if present and install a 1/2" diameter blocker rod with an approximate length of 2.95". Check to make sure the valve body will sit flush. If not, trim the blocker rod slightly until VB sits flush.

Set gear train and input shaft end play to the lower end specs. Also, Use a selective FLAT snap ring in both drums for setting clearance. Set the front band lever using an old over-running clutch roller (5/16" diameter) like setting mechanical rocker valve lash.


If you have any further questions, e-mail or PM. Glad to help.

John

OK thanks for the info.
I will look into all those issues.
That "PTK" cover.
I seen that it isn't in the PDF illustrations for my part number VB.
I can just make a flat blocking plate to take its place.

I bought this VB new in 1986 was in my Cuda until 2009 when I put a Jericho in that . Never had any failures in thousands of passes.
Not happy in this street application

Didn't know you used that VB in another trans. Since that is a manual shift body you have to block off the governor in the tailshaft. If you don't the trans will attempt to shift on it's own while you are trying to force shift it throughout the valve body, could cause problems.

Confused??
I thought the valve body did that by design?
I do plan on removing the governor now that its off anyway.
Is there something else that is required?

To remove the PTK, you simply remove the casting and use 3 short screws using the same steel cover plate. No need to make a new plate.

Also, no requirement to remove the governor weights. The Cheetah separator plate does not have a hole to feed the governor. I am using the Cheetah 17156 in two transmissions and still have the governor weights in place.


I would call Paul Forte at TA and get his recommendations on your set-up.

John

Uh, no. The manual VB has the automatic shift components removed.

As long as there are no cracks. The valves all move freely. The basic design of the turbo action VB doesnt burn up parts in my experience. My 9.0@3350# car is at 350 passes and counting on the same frictions and KD band. This isnt to say you can't make it better. But that's another deal.
Doug

My B&M reverse pattern, manual shift valve body purchased in the mid '70's required the governor to be blocked or removed. These newer ones might not need it.

Cope and T/A both told me to block mine so I did.
Also used the A&A billet stuff

I've never blocked them in nearly 30 years of trans building.
Doug