I have been getting some issues with my rpms on my 96 5.2L. I have ruled out the normal tranny issues like fluid level and color, and I changed the filter and fluid about 15k miles ago. After I park after driving on the steep hills on my ride home I can smell what seems like the tranny overheating. I'm beginning to suspect my TPS as I have been getting low idle and driving rpms. So, I guess I'm wondering can an issue with the TPS cause a tranny to overheat? I would think that it would, but I figured I would ask for others' opinions. This would help to rule out my tranny concerns.

 

The TPS won't cause the transmission to overheat. I would look for a transmission fluid leak that is burning off of the exhaust.

 

Well that's good. So, could the TPS be a culprit for the idling issues then?

 

Maybe, but the IAC motor is the most likely cause.

 

I cleaned the IAC recently. Can you backprobe it to see if it's shot?

 

You might want to check your trans cooler for flow. My 97s aux cooler was plugged solid and had to be power flushed to clear it. The trans itself was toast so I don't know which problem started the whole failure thing.

 

My plugged lines lead to me destroying my tranny.

 

Well, the cooler lines are new. I crunched them and the y-pipe so I replaced all three. So is there a DIY way to flush the tranny cooler? Or do I need to get it flushed at a shop? The engine has almost 200K on it and I heard high mileage engines shouldn't get their trannys flushed. My father-in-law had his flushed around 210K miles and it ended up toast. Any validity to this?

 

I would just check it for flow by disconnecting the return line and starting it up. You may need to check it in neutral but IDK. It should flow freely at about 40 psi, so direct it into a bucket. The return line is the one that goes into the tranny most rearward.

On the tranny flush, If it's been done regularly, it's okay, but if not, I would only change the filter and the amount in the pan. A power flush can break loose clutch glazing and plug the valve body and solenoids. It's good to clean out the pan anyway because there may be fine powder material in it that you don't want stirred up and recirculated. GM trannys have a magnet in the pan so you can see if you have steel parts wear. This would be from gears, bearings, and clutch plates. Not good. If jeeps don't, it might be a good idea to put one in. Fine silvery grey stuff is from aluminum clutch housings and clutch friction plates.