01 Blazer Transmissions

We have a 2001 2WD Blazer that has the original transmission that has been rebuilt 3 times. When if first went, we were told that that year tramsmission has a defective - aluminium - sun (?)shell. The thing went again for the 5th time. We have a lifetime warranty from Aamco. It seems like GM knew about this problem and have left people to deal with it.

You’re talking about the sun gear reaction shell. And yes, for what’s asked of this component it should have been built a little beefier. There is someone who provides an aftermarket shell that is built a little beefier to eleminate this problem. I saw it on one of the weekend car shows. Do an internet search.


Thanks. Yes that is the right part. I just hope that we can get the vehicle to the Aamco for this repair again.

I found it. http://www.hotrod.com/techarticles/113_0704_700_r4_transmission/input_shaft.html


You’re going to be searching for eternity before you ever find a vehicle made by anyone that does not have a weak point or two in a transmission.
The 4L60E is not a bad transmission at all so the question should be asked: Are you changing the trans fluid/filter every 30kish miles?

Your problem is not with GM at all. It’s with whoever has allegedly “rebuilt” this transmission 3 times. Maybe the word “rebuilt” is a misnomer because the person doing the rebuilding is supposed to remedy any probems while it’s apart rather than fling a set of clutches and seals at the transmission and call it a rebuild unit.

Any rebuilt transmission that fails repeatedly is failing for 1 of 2 reasons.

  1. You’re flogging the vehicle to death.
  2. The person doing the rebuilding is doing a very lousy job of it.

This is the sun shell:

They break at the collar. The sun gear which is sitting on top of the shell in this pic has the collar still attached to the splines. This is a very common problem with the factory GM 4L60E’s. When I build these, I use an aftermarket sun shell called “The Beast”. That 4L60E should never have to be rebuilt again if properly done. If you are out of warranty with AAmco, go somewhere else.


And you can change the tranny fluid all you want. It ain’t going to save the sun shell.


The never touched other than fluid changes, 240,000k miles 4L60E in my son’s Camaro has never shucked a sun shell even with some moderately hard driving and a few drag strip passes.

So 3 rebuilds later, staring Number 4 in the face, and it’s GM’s fault?

The OP states "when it first went, we were told…etc, etc.).
So that begs the question, if they were told from the get-go what the problem was then why didn’t this problem get resolved on Rebuild Number One?

We’re to believe this '01 vehicle has already trashed 4 sun shells and the OP never questioned why the problem was not resolved on the first rebuild?
That also begs another question. If someone is actually shucking sun shells on a regular basis then it’s not likely a parts defect problem because GM had zero, zilch, and nada to do with any of those rebuilds.

As per the usual, I think a lot of story is missing.