Pilot Bearing Problems - thoughts?
 

I just had the pilot bearing seize up in my 3rd gen the second time now. It basically welds the engine to the transmission. Anyone else have pilot bearing reliablity problems?

For those who havent had this problem, the symptoms appear like the clutch isnt working. The pilot bearing, a set of ball (roller) bearings breaks, wedging itself between the engine and the very tip of the transmission.

I am going to replace it again, but before i do, advice from the elders would be greatly appreciated.

happened to me. the bearing wasnt inserted properly by the other person and there was no grease seal

make sure grease seal is there, lube it up and make sure it seated properly in the hole

If you are installing it properly (i.e. correct depth and lubricated) and you are still trashing the pilot bearing, then your tranny input shaft is damaged.

Yep, most likely a bent transmission input shaft.

check how far into the e-shaft your putting it. the one in my car that was in there when i got it and failed was flush with the end of the shaft. it needs to be about 1/2-3/4"(i cant remember exactly) into the end of the shaft, then the grease seal sits against that

Do a runout check on the input shaft.

Although if you've already seized a pilot bearing then the input shaft probably also had a bad finish on the journal surface.

Dave

Another thing that can happen is it gets damaged when mating the tranny to the engine. If it's not a straight in shot and you force it you can damage the bearing.

had this problem w/ my last FD, had to replace the trans... input shaft kept taking pilot bearings out

I've had 4 rotary cars & getting ready to replace my 4th PB. I'll likely replace with clutch, flywheel, etc. I'm trying to find a reference to a "heavy duty" PB that I recall seeing over a year back, either here or at RX8Club, but no luck, so far. Anyone recall seeing those? Suitable for street and occasional track?

I doubt it. Pilot bearings are just needle bearings, and unless you machine the input shaft or e-shaft to accept a pilot brg with bigger needle rollers the strength will always be about the same.

Dave

If a previous bearing welded itself to the input shaft, test fit the new bearing on the input shaft before installing it. It should be fairly snug with minimal even play and no binding.

...you may notice (before you tighten down the pressure plate) that there is enough play to offset the clutch even with an alignment tool. When you have the alignment tool set as perpendicular as possible run your fingers over the edges of the clutch and pressure plate to see in the spacing is even left to right and top to bottom, before tightening down the pressure plate. If the trans does not easily slide in don't force it, or you can easily damage the pilot bearing and seal.

Make sure that the tranny to engine surfaces sit flush before tightening any of the mounting bolts.

If the tranny to engine bolts are not torqued and the eventually loosen, this can lead to bearing and input shaft damage.

I am resurrecting this thread to contribute my experiences since my initial post.

Two months later, the squealing noise resumed until the new bearing seized.

I did not:
Grease the bearing
Have a seal to install

Both of those gems of information were contributed after i installed the unit.

I fear the input shaft is trashed. Any experience (preferrably positive) with life after a bearing failure?

I have ordered a new bearing and seal this time. (i ordered a clutch set last time wo/ seal) I will grease it up as well, if the thing isnt totally trash.

My original PB broke up after the seal failed and the lubrication ran out. It was bound up for awhile, but eventually cleared and I drove the car for 5 or 6 years without the PB and had no problem with it (although it was probably a little hard on the input shaft bearing).

When I eventually had to pull the tranny to replace a broken clutch fork, I cleaned & polished the input shaft with a file and fine emery cloth. I also made tools to properly center and seat the pilot bearing and seal. That was in 2002. I just pulled the motor and the PB and input shaft were fine, so I'd say that it's possible to reuse a less than perfect input shaft (as long as the burrs are removed). At the time, I used a moly type wheel bearing grease, which is what the factory recommends for the PB.