Trans slipping when cold
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12 Second Club
Joined: Feb 2012
Posts: 419
Likes: 4
From: Long Beach, MS
Trans slipping when cold So I just had a local trans guy rebuild my 4l60e. Basic stock rebuild with the addition of a smart shell and transgo HD2.
I got the car back and the trans shifted ok. Trans fluid was a little high, the guy said he wouldn't worry about it. I've been driving it to work and back every day. have about 125 miles on it now.
I haven't really romped on it much, just a couple times to check take off and wot shifting from 1-2.
This morning I cranked up and pulled out of the driveway, it seemed to slip some going down the road at low speed, light throttle, just felt like it was dropping into neutral. It didn't do it anymore once warmed up, but I did smell trans fluid a couple of times while on the way to work.
What would cause this?
I'm giong to get a hold of him this evening, just looking for some input.
Also there is a little more noise with this trans than the last one. just hear it at idle, almost like a whirring sound, maybe the pump? Don't know if that's normal.
I got the car back and the trans shifted ok. Trans fluid was a little high, the guy said he wouldn't worry about it. I've been driving it to work and back every day. have about 125 miles on it now.
I haven't really romped on it much, just a couple times to check take off and wot shifting from 1-2.
This morning I cranked up and pulled out of the driveway, it seemed to slip some going down the road at low speed, light throttle, just felt like it was dropping into neutral. It didn't do it anymore once warmed up, but I did smell trans fluid a couple of times while on the way to work.
What would cause this?
I'm giong to get a hold of him this evening, just looking for some input.
Also there is a little more noise with this trans than the last one. just hear it at idle, almost like a whirring sound, maybe the pump? Don't know if that's normal.
Last edited by fbody_brian; Oct 24, 2013 at 09:24 AM.
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From: Ann Arbor, MI
The correct way to diagnose this will be to put a trans pressure gauge on it and check the pressure when cold and you think it is slipping.
Does it slip in all gears?
Yes, it could be a bad pump (whining noise).
A bad EPC (pressure control solenoid) can cause low line pressure, but if its slipping under light throttle, I don't think that is the case here.
I would also get the ATF level correct; I've been told that even 1 Quart too high can cause problems.
Does it slip in all gears?
Yes, it could be a bad pump (whining noise).
A bad EPC (pressure control solenoid) can cause low line pressure, but if its slipping under light throttle, I don't think that is the case here.
I would also get the ATF level correct; I've been told that even 1 Quart too high can cause problems.
Thread Starter
12 Second Club
Joined: Feb 2012
Posts: 419
Likes: 4
From: Long Beach, MS
Yeah, I'm going to try to get some of the excess fluid out today.
It will probably be as difficult to troubleshoot as my LT1 dying while driving down the road.
I post a thread about it and it quits happening! lol
After it slipped yesterday morning it hasn't happened again. driven it another 75 miles.
Think I may drop the pan this weekend and drain some of the fluid out and check to make sure the filter has a good seal, as I understand if they don't, the pump can suck air and make some noise. Trans has been shifting great though.
The slipping may be from the shift lever cable i suppose. It's bushing disintegrated and it's held in with zip ties. Doesn't feel like it moves into the drive position cleanly. Going to the u-pull-it and try to grab another one.
Anyway thanks for the reply.
I'll update this if I find what actually caused the issue.
It will probably be as difficult to troubleshoot as my LT1 dying while driving down the road.
I post a thread about it and it quits happening! lol
After it slipped yesterday morning it hasn't happened again. driven it another 75 miles.
Think I may drop the pan this weekend and drain some of the fluid out and check to make sure the filter has a good seal, as I understand if they don't, the pump can suck air and make some noise. Trans has been shifting great though.
The slipping may be from the shift lever cable i suppose. It's bushing disintegrated and it's held in with zip ties. Doesn't feel like it moves into the drive position cleanly. Going to the u-pull-it and try to grab another one.
Anyway thanks for the reply.
I'll update this if I find what actually caused the issue.
