1995 Cheyenne 4L60E shifting issue

[Roanoker494]

First I apologize for the vagueness of this thread but I am relaying the info I am receiving from the seller.

I have the chance to buy a 1995 Chevrolet Cheyenne that was owned by a local cemetery since new and is only showing 47K original miles. This truck has a short bed, 5.0L V8, 2WD and has a 4L60E automatic.

Here is the information I have on the trans for now (more to come once I hear back from the seller)
"transmission will not consistantly stay in overdrive. Truck can be driven in 1 and 2 with no problems (thats how I use it around town)."

I am no expert on this transmissions but isn't the 4L60E a four speed with overdrive? I am also not familiar with shifter layout on these trucks so maybe it is marked 1,2,D and it shifts through two gears in 1 and 2?

As of the moment let's assume it is only lacking overdrive. What are the possible problems? With only 47K miles I would assume the trans is not "burnt up" but more likely there is something stuck of sticking?

I have done some research on the 4L60E and have have found that the transmission has two shift solenoids that go through a pattern of on and off to control the various shifts. Is there also a controller for the overdrive? Is overdrive 4th gear or is it when the convertor locks up? I know I have had to replace a TCC sensor in many Grand AM automatic transmissions because the lock up was malfunctioning, though the normal problem was they would not unlock.

I appreciate any help that can be provided and I will update with new info as I get it. Unfortunately the earliest I can check the truck out personally would be next Tuesday, but even then I do not know enough about these transmissions to know what I was looking at.........

[stocker96]

My transmission guy told me whwen I had my 96 4l60 rebuilt that the ecm/pcm, has a ground loop issue which shuts off the 3/4 clutch lubrication. It's common and most transmission shops can get it knocked out really quick and for not all that much. I can't help with the technical side of this as I am a mess when it comes to the inside of automatic transmissions, just relaying info from my local shop. hope it helps. The 4l60 is a 4 speed, overdrive is when the converter locks up.

[Roanoker494]

I appreciate that information and I am with you when it comes to the internal workings of automatic transmissions, everywhere I have worked has always either just replaced the whole trans or sent it out to a trans shop. The seller claims he can get me a rebuilt transmission for $500, with core, and it has a 1yr unlimited mileage warranty but if the problem is electrical then that would just be wasted money.

Looks like the whole deal is a bust anyway because his response to my email was less than enthusiastic. I was told he did not have the time to explain the issue and I just needed to come and check it out myself............ All I asked is what gears the trans would go through in the various selections. I half expect he has bought the truck for a quick flip, has found out it has serious issues and is now trying to pass the headache along.