gongshow71

iTrader: (1)

My pilot bearing just grenaded itself again for the second time in 6 months.

I created this thread this past October: https://ls1tech.com/forums/manual-tr...ed-advice.html

I can't continue to dump money into clutch/transmission parts until I figure out what in the world is going wrong. The first pilot bearing that went out on me only lasted 23,000 miles. The 2nd pilot bearing that just went out only lasted 5,000 miles and took my T56 input shaft with it again........So I know something major is going on and I'm obviously missing something.

Current set up as of 2nd pilot bearing failure: all parts have 28,000 miles on them except pilot bearing
-New pilot bearing
-Monster 28lb flywheel
-Monster Stage 2 pressure plate and clutch
-GM slave cylinder
-GM master cylinder
-eBay speed bleeder line
-TDP Stage 2 T56 with repaired input shaft

Planning to purchase:
-GM LS7 clutch
-Factory flywheel or lightweight flywheel
-New slave cylinder
-Tick adjustable master cylinder
-New input shaft or repair the old one again
-Bronze pilot bushing

The only thing I can speculate as the cause is a faulty slave cylinder or a bent clutch disc. I've always had a disengagement issue but hopefully that can be taken care of with the Tick Adj master cylinder or shimming the clutch if needed.

Am I missing something here that should be obvious? I can't keep paying $1500 every 5000 miles when another pilot bearing goes out.

Can anyone explain in detail how to measure for a clutch shim?

Also, I think I need new motor mounts because they're the original ones. I replaced the transmission mount bushing the last time my pilot bearing failed with a polyurethane one. Could this be causing an alignment issue between the engine and trans?

Any advice or help would be appreciated.

AU Doc

Did you align your bell housing to make sure it's centered with the crank?

pdxmotorhead

+1 you cannot count on the dowels to do it right.. I've found several on various brands that had at least one that was wrong. You can buy some that have an offset for correcting alignment.

2ToeRacing

iTrader: (5)

A bushing would be best. Have you looked at the input shaft?? Is the front bearing bad in the transmission causing the shaft to wobble?? Your pictures look like there isn't any grease in the bearing but.....there little bearings are cheap but most last a long time.

gongshow71

iTrader: (1)

I guess I never really thought about bell housing alignment because wouldn't it be aligned if the bolt holes line up correctly with the block of the engine?

I put the flywheel, clutch, and bell housing on first, and then I put the transmission case up and bolt it to the bell housing. Am I supposed to be attaching the bell housing + trans before I mount it to the engine? How do I align the bell housing? It's the OEM bell housing to my knowledge.

Input shaft was machined and shimmed the first time the pilot bearing failed. This time around I think I caught it soon enough to where it didn't damage anything internally. The input shaft is tight and has the correct amount of play in it. I guess I will find out when I open it up to install the new input shaft.

And yes, the pilot bearing was greased when installed. I'm sure all of the grease dried up when the bearing went bad. I'm scared to run another pilot bearing instead of a bronze bushing because new input shafts aren't cheap......

pdxmotorhead

How tight is the hole/attachment in the bell housing to the transmission? Sometimes the bell is lined up fine, but I have had a couple T56 and T5's that had just a little too much play in the bell to transmission junction, i used some bushings around the bolts because The factory holes were just a little loose, and added up to about 50 thousands offset.. Also make sure the front and rear surfaces of the bell housing are parallel, I got a brand new SFI one that was aftermarket that wasn't,, caused all kinds of grief with the clutch throwout and pilot bearings..

gongshow71

iTrader: (1)

Interesting. I'll have to double check that the bell housing mating surfaces are smooth on the engine and trans case side. Do you install the bell housing and trans together as a unit? Or install the bell housing first and then mount up the trans?

AU Doc

Here's a video on bellhousing alignment

gongshow71

iTrader: (1)

Learn something new everyday. I never thought of aligning the bell housing, thanks guys. I'm confident the reason I've been trashing pilot bearings is because my input shaft isn't aligned properly due to the bell housing.

Here's another good video showing the process:

chrysler kid

iTrader: (14)

The flywheel burn marks are leading me to say the input shaft bearings are toast and if you've always had disengagement issues then the problem was never truly fixed

Make sure you use NEE flywheel bolts, and they are torqued in the correct pattern in two separate passes

Make sure the pressure plate bolts are all torqued evenly in the star cross pattern

A shim would not cause an issue like this.

I've never had a problem with a pilot bearing, Jason at Tdp built my trans and clutch and sold me an oem pilot bearing.

It says you're in dfw, just go up there and talk to jason, he will spend 2 hours explaining exactly what happened. He's like Sheldon from big bang theory about transmissions and clutches

stevieturbo

Post pictures of the failed bearing as it is in the crank.

Exactly what failed ?