In Serious Need of a 4T60E expert!!!!!

[KingPin_Chevy86]

my 97 tahoe (350 vortec/ 4L60E) drives, shifts perfect when you first start driving it. The TCC kicks in at 40mph on the dot and I can hop on the freeway and do 65-70+ no problem as long as im on the freeway with the TCC engaged. If I drive around town and do some stop and go for around 15-20 minutes and then hop on the freeway, I have no TCC lock-up what so ever. It does this about 95% of the time more often when its above 50* outside. When its hot I can almost count on it. Sometimes I can baby it into lock up by driving up to around 75-80mph at half throttle with no lock up and then let off the gas to the point where the throttle is just cracked open. after that it MIGHT slip into lock up. I haven't done anything to try and solve the problem yet because I dont want to just go into this without the slightest idea of what could be wrong. Any Help?? Ill buy drinks if we can get a sure fix to this (If your in the Cleveland area) this has been driving me NUTZ!! BTW after its starts to act crazy, 99% of the time its followed by crazy hard shifting 1-2, 2-3 and 3-4 but when its acting normal it shifts smooth as glass... WIERD?!?!

 

[sewlow]

Sounds like time for new servo's

 

[KingPin_Chevy86]

I thought about that but then I was also thinking pressure solenoid, and/or boost valve. The truck has 206,*** on it and has never been taken apart (engine or trans for that matter)

 

[JollyGreen]

Mine is doing some of the same things your describing except it only does it from 1-2. The thing won't slip AT ALL in the am, but on the way home after 15-20 miles (70 deg + weather) of highway driving it slips on the 1-2 shift. It's also doing something weird when I come to a stop light, like a clunk when I let off the brake that I think is coming from the rear end. Hope you get it figured out. Thought mine might be the valve body, but I know 0 about trannies. Think I might wait till it ***** out and get a new one.

 

[bizzo15]

Mine is doing some of the same things your describing except it only does it from 1-2. The thing won't slip AT ALL in the am, but on the way home after 15-20 miles (70 deg + weather) of highway driving it slips on the 1-2 shift. It's also doing something weird when I come to a stop light, like a clunk when I let off the brake that I think is coming from the rear end. Hope you get it figured out. Thought mine might be the valve body, but I know 0 about trannies. Think I might wait till it ***** out and get a new one.

Your clunk coming from a stop sounds like either the slip yoke needs to be greased or a bad u-joint. I have no idea about the OP's issue though.

 

[JollyGreen]

The u joint had crossed my mind. Didn't think about the slip yoke.

Thought the original poster's problem might be the valve body or maybe like sewlow said...servos.

 

[Tomcat71]

4T60E is a front wheel drive transmission...4L60E is a rear wheel drive...

 

[rhino]

Those are know symptoms for the converter regulator valve being worn.. They have a quick easy fix, from fitz-all. it involves dropping the valve body though. I would first run a code check and see if it has P1870. That would verify. It probably won't have the check engine light on, but run the codes anyway.

 

[GMCTRUCKS]

My buddy ran his Snap-On scanner on my 93 and it read a lot of stuff you might consider running codes.

 

[KingPin_Chevy86]

4T60E is a front wheel drive transmission...4L60E is a rear wheel drive...

I know. im jus so use to working on junk w-body cars that I have that trans stuck in my head. I ran the codes on my truck a few weeks ago when it was kinda warm out and the trans was displaying the symptoms and got absolutely no codes what so ever. I jus replaced my mass air flow and reset the codes a few months ago but I figured since the trans was doing its act then I should have had something but no. im baffled I need to get this corrected before spring time. at this point im considering dropping a grand or so for aamco to rebuild the damn thing.