4L60E Squeak

[87Skier]

My 4L60E has been squeaking for a while. Turning the tires with the rear end off the ground or running the vehicle it is clearly audible, and it sound likes it is in the rear half of the transmission.

I thought the output shaft snap ring failed, but when I removed the transfer case, the shaft felt solid and wouldn't move more than 1/8".

So, what is likely wrong with this 4L60E? It is a 1997 model with I suspect about 250,000 miles. Not sure how many on the rebuild though. I've read that sometime a rear planet will cause the squeak. Any thoughts?

[68gmsee]

I have found that a 3 foot section of stiff garden hose works good as a stethoscope to isolate noises to a particular area. You can direct one end to the suspected area without you or your hand getting in the way.

Since you can duplicate the squeak while parked, you may be able to isolate the exact location on your truck (safety in mind, of course) or you can take it to a shop with a lift to see if they can at least locate the area it's coming from.

[Bigdav160]

Sounds like you are turning the roller clutch. They make that squeaking noise when turned in the freewheel direction. Completely normal

running the vehicle it is clearly audible

That would not be normal for the transmission. Sure it's not a U-joint?

[YoungPup1977]

Does the noise change when the transmission shifts to different gears ? Or does it make noise in every gear ? Does the noise go away at all ?

[87Skier]

I'm very sure it isn't a u-joint. I crawled under it while running and shut-off. Any time the tires are turning it can be heard.

When the gf first mentioned it, I thought it was a u-joint or some brake noise, but the noise is definitely coming from the transmission output shaft in some way. It must be something directly splined to the output since it doesn't change speed/pitch when going from 1-2 or 2-3. The noise is about the same volume any time the vehicle is moving, and around about 30-35 mph, road noise/wind noise is louder than the squeak.

[YoungPup1977]

Could be the rear torrington bearing that sits against the case and the ring gear. Just a guess....

You had mentioned you pulled the Transfer case out, did you drop the transmission pan to see if any thing in the pan (metal)....

[87Skier]

I haven't pulled the pan yet.

I'm still trying to figure out what I want to do. I have other projects going on and this was supposed to be a weekend sort of deal, but I think I'm going to have to rebuild the transmission.