Ok, so a guy drives his car over for a clutch replacement, it's an 02 Z (not positive on the year) The car has just under 40k on it, and what an absolute mess. This car hurt my feelings. It's a blower car with a Vortech, and I don't know who built this car(I'm pretty sure I know but not gonna say)but it is an absolute shame the condition this car was in, not only from the crap install, but how the previous owner took care of it. Too many things to list.

Whenever doing a clutch replacement we always install a new pilot shaft bearing, and always recommend a new Slave cylinder/throwout bearing.

Anyway, here's the question.
What would you do about this pilot shaft bearing?

After removing a very badly worn out clutch, I find that the pilot bearing was installed wrong.


and here is the knurled bearing they put in. Knurled? Yep keep reading.....


Then I find out why it's knurled, has epoxy on it, and was recessed in so far.
When I go to put the new bearing in, it just slid right in there. Doesn't wobble or anything like that it just slides in and out with ease. So the 1st attempt was to kind of do my own knurling if you will by using a punch to raise up some of the outer surface for grip, as that is what was previously done with the help of the epoxy, the old bearing had "grown" about .004". When installing it like this I too would have to put the bearing in too deep to get it to hold, but after that I reached in and just pulled it back out with my little finger. So that is NOT going to work.

This car has an LS2 in it, and I'm pretty sure an aftermarket crank which is where the issue is. The LS2's pilot bearing is different, it rides on the larger diameter surface not like ours do on the C5's. However I believe this was the fault of the machine shop that made the crank as we have done pilot bearing change out before on LS2's that were in C5's and have never had this issue before.

So How would you solve this problem?

The owner of this car just bought it, and is installing a Monster clutch. After getting the install done and checking the clutch movement we find another HUGE issue, and do not feel that this motor will last much longer as there is massive end play in this crank, either due to poor machining or a very very worn out thrust bearing. You can actually see the flywheel move back and forth significantly.
Anyways just curious what others would do to solve this issue with the pilot bearing.

 

So no one has any ideas on how they would solve this problem?
Did I post this in the wrong section?

 

Wow, thats pathetic!

I have no suggestions other than to post in the Tech section.

 

Try Tech

 

Mic it and get a measurement. Then do some researching to find out if theres any other vehicle that uses that size bearing, or get the measurement on the crank bore for the bearing. If needed, you can probably get a slightly larger bearing with the same I.D. as the stocker, then drill it out to fit the bigger O.D. of whatever bearing you find.

 

Didn't have a set of calipers that would reach in deep enough to get a measurement on the crank. Best guess would be (based on bearing that came out) that I needed a bearing that would be about .005" to .007"
To do as you suggest correctly would require the crank to be removed for proper drilling.
Another route would be to put in a C6 bearing and change out the front shaft section of the torque tube to match. This was not within the finances of the car owner.

 

Check with a bearing house. With the original bearing dimensions or identification, check to see if a metric bearing might just work. The only other alternative is to bore and sleeve.
Now, there may?? be a possibility of a bearing with a larger od dimension that could be installed with drilling the bore a little larger. This can be done with a magnetic base drill.

Either way, its not going to be an "easy" fix. I always say that i will do everything i can to help a customer, but i wont let "their" problem become mine.

 

Maybe find another bearing with the same inside measurement but a larger outside diameter and have it machined to fit?

 

The members in the Tech section might be able to give you an answer. Some very knowledgeable people over there.

 

 

Trying to Knurl yourself IMHO is a very bad idea.

If it were to fail then it would be your fault (in the opinion of the customer and the next shop he takes it to).

I would find another bearing with the correct inside diameter and an over sized outside diameter then machine it to the correct size.

I would not touch the crank. The last think you want is be accused of messing that up.

I would also document in writing the current problem and what you recommend as a fix with the owner signing it before any work is done.

It can be fixed without much difficulty. I mean s**t how long did it run with epoxy in it?

 

.002/.003 can be done with Locktite Baring Lock, I don't have the number but you can goggle it. At .007 there is little you can do. If you know someone with a lathe they might re cut knurling on the new baring. Doing anything like this is cheep/temporary fix and you will be risking your reputation. Think your client should find budget to do this wright.

 

its likely an eagle crank. they messed something up with their deisgn at some point along the line and the bearing journal is oversized. I have an eagle crank on my z06 and shortly after buying it I pulled the driveline to diag. a shifting issue I noticed the same thing.





Pilot bearing just slides in and out with no problem. Rather then fix the problem correctly for the previous owner, cartek just threw a new GM bearing of the wrong size in there and called it a day. This one just one of MANY half *** things I've fixed on the car since owning it.

I have all the measurements written down in my log book if you need them but its at home. Basically, what you want to do is call up eagle and tell them what crank you have and they will send you some oversized bearings at no charge. I have 4 of them 'just in case' for later.

good luck