need advice on trans problen
05-14-2005, 06:42 AM
#1
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need advice on trans problen Before pulling trans trans(4l60e) worked great, Had rebuilt now no 2-3 shop has had it for 6 weeks,Pulled back out ot car and rebuilt again still doesnt work says something in valve body and is going to put new one in then says if thats not it its electrical,NEED SOME ADVICE TO MAKE SURE IM NOT GETTING SCREWED THANKS.
Last edited by 1FASTLS; 05-14-2005 at 07:21 AM.
05-14-2005, 02:49 PM
#2
It sounds like they don't know what they're doing or not spending enough time on it, maybe they're too busy working on other peoples stuff.
They didn't pull it back out to rebuild again, they pulled it back out, took it apart and checked everything.
They should be able to wet air test the 3-4 clutch to make sure it tries to apply.
It could be something assembled wrong in the 3-4 piston, apply plate, clutch stack.
Could be the band sticking and making it bind staying in second and third.
Could be a valve put in wrong. Bad solinoid.
It could be so many things.
I really don't see how telling you any of this is going to help if someone else is doing the work.
If you have to suggest to them what to check then you're all on the wrong track.
They didn't pull it back out to rebuild again, they pulled it back out, took it apart and checked everything.
They should be able to wet air test the 3-4 clutch to make sure it tries to apply.
It could be something assembled wrong in the 3-4 piston, apply plate, clutch stack.
Could be the band sticking and making it bind staying in second and third.
Could be a valve put in wrong. Bad solinoid.
It could be so many things.
I really don't see how telling you any of this is going to help if someone else is doing the work.
If you have to suggest to them what to check then you're all on the wrong track.
05-14-2005, 02:58 PM
#3
could be pcm. I SWORE my tranny builder had not done something right with the 2-3 shift stuff. It NEVER shifted once without hitting the limiter at WOT. Turns out I just found a screwy parameter in my tune that was causing it. Went to the track last night and it worked flawlessly after not shifting ONCE on the 2-3 since Thanksgiving. I had to call him and say "uhh...you were right..it's not the tranny."
05-14-2005, 03:14 PM
#4
Originally Posted by cablebandit
could be pcm. I SWORE my tranny builder had not done something right with the 2-3 shift stuff. It NEVER shifted once without hitting the limiter at WOT. Turns out I just found a screwy parameter in my tune that was causing it. Went to the track last night and it worked flawlessly after not shifting ONCE on the 2-3 since Thanksgiving. I had to call him and say "uhh...you were right..it's not the tranny."
I had one 700R4 I built to stock specs and it worked great with a low power engine.
Then I added about 120 hp with heads and cam and the 2-3 shift started flaring.
I took the trans out and only changed the 3-4 clutch clearance.
It shifted perfect and held strong.
Now the 4L60E in my camaro has the same problem, just not as bad.
2-3 shift is slow. Put in a transgo shift kit and even made changes beyond the instructions to get 2-3 to shift better.
Better but not what I wanted.
I don't feel like pulling that trans out right now just to change the clutch clearance. So I raised the 2-3 upshift pressure modifier by tuning and it almost completly eliminated the problem.
I look at it as putting a baidaid on the real problem but it works for now.
Now as far as tuning goes, I can't see why it would stop shifting into third after just pulling the trans and reinstalling it. Hell you could take your VCM out of the car and ship it to china and back and it's still going to have the same tune in it.
The forward drum has a ton of parts in it including the 3-4 clutch. There is a lot of room for mistakes.