Tranny/ servo failure?
Thread Starter
TECH Apprentice
Joined: Oct 2006
Posts: 322
Likes: 0
From: Wichita, Ks.
Tranny/ servo failure? I purchased a Performabuilt Level 2 4l603e tranny with a Compushift controller for my 69 Camaro LS7 project. I installed it with a Yank SS 3200. After the Initial Dyno we had the car on the road for 20 to 30 mins. and found that we didn't have 2 gear.
Had a well respected local drag race tranny guru rebuild it. He stated that the aftermarket servo stuck and burned the clutches, lost 2 and overdrive.
The servo was a billet servo that my tranny guy has had some trouble with in his past builds. I have sent the parts back to Frank at Performabuilt for evaluation.
The rebuilt tranny with a stock Corvette servo is now working well. Has any one else had problems with aftermarket servos? I know they are used alot in builds. Or could there be another problem that lead to this tranny failing? Thanks
Had a well respected local drag race tranny guru rebuild it. He stated that the aftermarket servo stuck and burned the clutches, lost 2 and overdrive.
The servo was a billet servo that my tranny guy has had some trouble with in his past builds. I have sent the parts back to Frank at Performabuilt for evaluation.
The rebuilt tranny with a stock Corvette servo is now working well. Has any one else had problems with aftermarket servos? I know they are used alot in builds. Or could there be another problem that lead to this tranny failing? Thanks
On The Tree
Joined: Jun 2007
Posts: 165
Likes: 0
From: haltom city/DFW, Texas
The larger the apply area on the servo , the more holding capacity the band will have . From the factory there were three or four servo sizes that had varying apply areas . # 554 being the smallest 093 "corvette" the largest .
The fourth piston was the same in all the factory servo's . There are some aftermarket companies that make "billet" servo's that are larger than any stock ones , and also have a fourth only "billet" that is a nice piece and worth the money .
These are only for more holding / clamping force on the band ! They do not have any thing to do with band clearance adjustments which are controlled by pin length . It is critical and must be checked upon assembly of the transmission . Shift timing issues have always been a problem with both the 700R4 and the 4L60E and also must be calibrated to the servo .
I have always had good service using the Vette servo and a shift kit but a nice billet servo or a fourth piston is a bonus
Losing second and fourth indicates you lost the band , but it could be as simple as a damaged seal or a clearanc issue !!!
The rant is now over
The fourth piston was the same in all the factory servo's . There are some aftermarket companies that make "billet" servo's that are larger than any stock ones , and also have a fourth only "billet" that is a nice piece and worth the money .
These are only for more holding / clamping force on the band ! They do not have any thing to do with band clearance adjustments which are controlled by pin length . It is critical and must be checked upon assembly of the transmission . Shift timing issues have always been a problem with both the 700R4 and the 4L60E and also must be calibrated to the servo .
I have always had good service using the Vette servo and a shift kit but a nice billet servo or a fourth piston is a bonus
Losing second and fourth indicates you lost the band , but it could be as simple as a damaged seal or a clearanc issue !!!
The rant is now over
Last edited by big wally 55; Jun 13, 2008 at 06:59 PM.
We use the billet servo in every level 2 and 3 build. We have never observed any issue with the servo getting stuck or otherwise causing any issue with our units and there are 100s out there since the level 2 and 3 are our biggest sellers. Dave did purchase this trans from us in late 2006 and he contacted me about a shift issue. However at the time we agreed it might be a possible tuning error or something with the PCM. I told him at that time to keep me posted. Now I was informed a few weeks ago he had it repaired and up until that time he never ask or contacted us anymore about it. And was told only that the trans guy he had fix it said the billet servo got stuck and that he had changed the clutch sets to his preferred brand and type. We were never contacted about warranty or even kept informed of anything until now that someone else fixed it.
As for what actually caused the failure its unlikely we will ever know. The servo becoming stuck is unlikely as is that it caused the issue or we would have seen many with that problem by now I would think. And its commonly used in many other builds also. Could it have been a damaged seal possibly? maybe, Trouble is no one will ever know for sure since we never got the opportunity to inspect it and the explanation given does not make sense. We did get to see the servo which appears fine and we did see the band and 3-4 clutch set which were burned. Presently we are evaluating what to do in this very unusual case. Basically we have been ask what we intend to do and the answer for right now is we don't know yet what we should do.
As for what actually caused the failure its unlikely we will ever know. The servo becoming stuck is unlikely as is that it caused the issue or we would have seen many with that problem by now I would think. And its commonly used in many other builds also. Could it have been a damaged seal possibly? maybe, Trouble is no one will ever know for sure since we never got the opportunity to inspect it and the explanation given does not make sense. We did get to see the servo which appears fine and we did see the band and 3-4 clutch set which were burned. Presently we are evaluating what to do in this very unusual case. Basically we have been ask what we intend to do and the answer for right now is we don't know yet what we should do.
__________________
Thread Starter
TECH Apprentice
Joined: Oct 2006
Posts: 322
Likes: 0
From: Wichita, Ks.
Thank you John, very informative. When it was rebuilt we replaced it with the new servo, added Blue Plate clutches with 2 extra clutches and added a TransGo shift kit instead of just drilling holes in the plate, left out the accummilators. The tranny works well now, shifts great. Put about 200 miles on it without problems. Rant??- no problem!
Well its true we do not leave out the accumulators? and we use the ZPACK in the level 2 build , We did use the blue plates in our level 3 build at that time but have since switched to raybestos Stage 1 set as some felt the blue plates a little aggressive on th 2-3 but then if you block (remove) the accumulators all shifts will be IMO overly aggressive so that would be a mute point.
__________________
Thread Starter
TECH Apprentice
Joined: Oct 2006
Posts: 322
Likes: 0
From: Wichita, Ks.
Thanks for the reply Frank, it is true that I did not send back the tranny to Performabuilt. This is a special build for me, a 69 SS/RS Camaro vert with a wet sump LS7, built with a Pro-touring style in mind. I have waited 18 months to road this beast. I went with a local tranny builder with a great reputation to lessen any down time and if something is to fail I can get it checked/repaired quickly, without shipping costs and time.
Frank has been upfront and honest and genuine in his concern. I believe Performabuilt stands behind their product. I returned the parts to Performabuilt over a month ago but when I talked with Frank recently no mentioned was made of the servo being checked out as fine, so I didn't have that info. I posted this topic to better understand why the tranny may have failed, if there are any others with similar servo issues or if there was another possible explanation. This site has alot of traffic with alot of experience so I appreciate any disscussion. Thanks Frank for any information you can provide.
Frank has been upfront and honest and genuine in his concern. I believe Performabuilt stands behind their product. I returned the parts to Performabuilt over a month ago but when I talked with Frank recently no mentioned was made of the servo being checked out as fine, so I didn't have that info. I posted this topic to better understand why the tranny may have failed, if there are any others with similar servo issues or if there was another possible explanation. This site has alot of traffic with alot of experience so I appreciate any disscussion. Thanks Frank for any information you can provide.
