What causes TO bearing to be so scarred at 5k miles?

[Baby]

When my throw out bearing took a crap, I replaced it, the clutch, flywheel, pilot bearing, and other associated parts. Prior to the repair, I had never had the motor out and in. I got on the road again, and things went well for the first few short drives. But when I took the car out on the freeway and was giving it some juice and working the pedals with some vigor, I felt something kind of give, like maybe the clutch cable had stretched. I limped the car home, about 25 miles. It smelled like fried clutch or metal or something, and there was some smoke.

Turns out I had installed the new clutch cable in a way that it had been tangled with the throttle cable. When I worked the pedals hard, the cable "readjusted," I thought causing the clutch and flywheel not to separate enough when I shifted or in some way only partially engage when I drove. When I re-routed the clutch cable and adjusted it, the clutch worked great. I figured maybe I hadn't fried it all and I didn't to in again to check for damage.


5k miles later, with a broken head stud, I drop the motor again and find the throw out bearing pretty beat up. (Clutch and flywheel look great.) There is ground metal all over it and the guide tube (which is less beat up). So my question (finally), could this be the result of my mis-installation of the clutch cable? Could it be the result of something else I need to look out for? Any and all help is appreciated.

[pharlap71]

do you have photo of the snout on the trans that this slides on?

[timmy2]

I'm assuming you put the bearing in a solvent bath to remove all the grease, and it didn't come out that clean....

[Baby]

Sure do.

[pharlap71]

its hard to believe that the snout is not scarred, the TO loosely slides over the snout, more of a guide. I sprayed my snout with teflon spray. Is it a SACHS TO? The scarring looks like it is front to back rather than circular, which indicates the scarring happened as the TO slid back and forth, I don't understand why the snout is not showing the same scarring.

[Baby]

Timmy2, I scrubbed it a bit, but no bath. It had hardly any grease on it, and the part of the interior with the deep grooves didn't have any grease on it. Phar, yes, it's confounding. One half has the deep grooves from a thrusting motion; the other half has lighter thrust grooves but also spinning grooves. The guide tube was brand new with the TO bearing. I believe it is Sachs. It's from pelican.

[Fishcop]

Never seen anything like that before! The tube and bearing surface are meant to get grease...

[john walker's workshop]

what kind of grease did you use?

[hcoles]

Originally Posted by Fishcop

Never seen anything like that before! The tube and bearing surface are meant to get grease...

When I look at the roughest part, it looks like material is raised or upset in some way not caused by sliding friction, I vote for it was installed with this issue or the or at least a big start on it. If you put a straight edge on the two surfaces is one higher or lower than the other? This might help finding the root cause.

[mreid]

Does the pilot bearing in the flywheel fit over the tip of the tranny input shaft with no slop? That looks like what happens when the pilot bearing fails, is missing, or is incorrect for the application.

[HawgRyder]

The part looks like it has "chatter" marks.
This would agree with Mreid as to the fit of the TO on the guide...too much play?
Bob

[rgmrgm]

check for bad or missing pilot bearing, throw-out lever shaft play, bad fork

[DRACO A5OG]

Originally Posted by john walker's workshop

what kind of grease did you use?

+1

[CCM911]

+2

I generally smear just enough grease on mine. Not a little, but not so much as it will be thrown out onto my disc.

That almost looks like bad metal on the throwout bearing.

Originally Posted by john walker's workshop

what kind of grease did you use?

[kodioneill]

He stated that the cable was fouled up in the throttle bell crank maybe the bearing is cooked because it was under tension from the cable and touching the pressure plate, burned up and seized.

[M.D. Holloway]

ouch

[Baby]

For clarification, I installed the TO bearing new, purchased on this site as part of the Sachs clutch kit. The pilot bearing, fork and seals were new as well.

The two halves of the TO bearing are even, considering the gouges.

I used the grease from the Sachs kit on the input shaft and high quality Redline synthetic grease left over from a motorcycle engine build on the guide tube. (Yeah, I asked the board after I put it all together and learned that white lithium is better.) Conceding that I didn't use the best grease, I don't know that the wrong grease would cause such deep gouges.

As for slop, it all seemed to fit together pretty well. Seemed like the correct pilot bearing.

Also, for clarification, the TO bearing didn't seize or disintegrate. Once I fixed the cable, everything worked great for 5k miles. I was surprised to see the TO bearing so chewed up.

Thanks for your input.


The TO bearing new:



Pics of the assembly process for the TO bearing here. (There is a brief video of me showing the play in the TO bearing installed that shows the inside surfaces in new condition.
911SC Garage: Installing the Clutch Disk, Spring Plate, Throwout Bearing, and Starter Ring

Here is a pic of the pilot bearing NOW:


Pilot bearing when I installed it:

[Baby]

Weekend bump....