Overdrive won't respond

[Sonyman]

When driving at required speed, overdrive wont kick in. I know on a cold start vehicles in general it wont do it until about a couple of miles down the road but mine just won't. Fluid and filter is good so what do you think? Torque converter or a internal transmission issue? Holla back

[Z26-T]

what year of car/type of trans?

[gpse3400]

Are you sure it is not the Torque Converter clutch? Yeah year make and model would help.

[Sonyman]

ok its a '91 Pontiac Grand Prix STE with 3.4 It has a automatic 4T60E Tranny.

[Sonyman]

If it was the TCC, how does it look like and where is it located?

[Z26-T]

a 91' with a 4t60? I thought those had 125cs... But what do I know. Chances are you will either need the Torque Converter Clutch Solenoid or a Torque Converter.

[Sonyman]

where is the solinoid located?

[Z26-T]

In the valve body. In the TH125C they're fairly easy to do, but in the 4T60-E they're a bit harder. You have to drop the pan and if you'll look the left side of your engine compartment, you'll see your trans under your air intake, and you'll see how there is 2 sections to it. Underneath that cover is where the valve body is.

[pocket-rocket]

Yeah, the 91-9? LQ1 cars got the 4T60-E, not the 125c. And on a side note (no pun intended) I don't think that side pan will come off with the engine/trans in the car, which is why Z26-T said the 4T60-E is a bit harder.

[Z26-T]

I've seen a few guys sneak them out... but it's a B. Pretty sure they drop the cradle and drop the engine/trans down a bit. Personally, if you're not a big car guy, a do it yourselfer a lot, I'm not sure if you would want to tackle this. It's really easy to mess up trannies . Not trying to discourage you or anything, more trying to help you from heart ache. If you do it yourself, the car will be down for a few days vs. having it done some place in a couple days. I'm not sure how busy the repair shops are around you, but everything in my state is dead. We've been standing around for a few days now since it's tax season so they should be able to get you in pretty quickly. But it wont be cheap...

[gpse3400]

yeah I've done it a bunch of times before...lets just say that you are going to lose the alignment when its all said and done unless you pull the engine out and then the transmission all out the top. Nstually you will want to verifiy operation of the soleniod before doing any of this.

[Z26-T]

Yeah, make sure it's the solenoid that needs to be replaced . This just happened in my friends monte carlo, we replaced the valve body and the tcc solenoid and it didnt fix the problem.

[gpse3400]

the TCC is strange....Things have to be just right for it to work. Soleniod filters liek to get clogged if you get any grit in the VB

[Z26-T]

It was all brand new stuff from GM .

But mostly this is stuff you gotta think about if you want to fix your TCC lockup . If you take it to a shop and they mis-diag it and fail to fix the problem, well they better warranty their repair and fix what they messed up .

[Sonyman]

allrighty thanks for the input i'm going to pull the engine/tranny out this weekend and put in another tranny waiting on stand by, gonna use the same torque convertor. I wanted a new convertor installed but its so hard to find a auto store that has one. They claim its unavailable and im leaving town tomorrow to do the job. I'll have to take my chances that another tranny will solve it in hopes its not also the torque convertr. I'll holla back when i get back and let all ya'll know.