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.