Thread: Release Bearing wear... Where?

Hey All.

I am in the finishing stages of assembling my all-motor setup for my NX2000. After a bit of a dough-head move resulting in the ruining of a release bearing (another story, another time), I had a couple of questions regarding release bearings:

I now understand the mounting of the bearing on the sleeve, and how it is actuated by the forks. I also realize that, in essence, there are two critical areas to be concerned with in terms of wear on a release bearing; One, being the inner bore of the bearing housing that slides on the surface of the input shaft sleeve, and Two, the bearing race itself (I suspect that the bearing would wear out long before the contact point that presses on the pressure point fingers would).

So, my questions center around this:

What part(s) of the release bearing is/are responsible for symptoms associated with one worn to the point of requiring replacement? There don't seem to be limits associated with inner bore diameter, nor axial play, detailed in the FSM. I realize this is not an expensive part, and the money spent on a good replacement part is far cheaper than the labour/time associated with pulling the tranny to replace one. Having said that, what makes the release bearing ready for the scrap pile?

Thanks much for any input; looking forward to hearing some thoughts on this!

Darrin

Whenever you pull the tranny, replace the bearing regardless of the amount of wear that is visually apparent. I've never had a problem with my TOB so I'm not sure what constitutes a need for replacement, but I've always installed a new one while I was in there.

Also 3) The spring clips that attach the CRB to the fork. While it won't allow play the metal does tend to wear a bit where contact occurs.

Did a clutch on a GA16DE NX a month or so ago with 120,000 miles.
Disc was fried and the pressure plate and flywheel a bit blued from the heat, and the CRB sounded rough when spun by hand. Sounded gritty. No real wear in the centre bore that slides on the tranny input.
I wasn't impressed by the replacement CRB in the clutch kit, made by a company in the UK called Quinton-Hazell. Generally their stuff is great but they'd updated the CRB design to do away with flat ends that you'd attach the spring clips to, and replaced with metal tabs bent over at 90 degrees with a small oval hole that's supposed to pop over the tiny pins on the fork. The new CRB was supposed to be self centre-ing and wasn't anywhere close to being centred from the factory which allowed it to fit to the fork on one side and be miles out on the other...

Also, you can sometimes hear a bad CRB in the car when you depress the clutch pedal. It'll whine or sound generally rough.

I say if it has low miles and is in good shape, reuse it. If it ain't broke, don't fix it. You would hate it if you put in a defective bearing when your low mileage one worked perfectly.

spring, and always replace the bearing reguardless

The TOB is a ball bearing. It will not fail until the balls or separator or races wear so bad that the balls fall out. However, it will get noisy as it wears and loses lubrication. It will feel rough (or gritty) when rotated. Same as wheel bearings. They get noisy long before they fail. If you don't replace the bearing with the clutch, you run the risk of having it get noisy before the clutch wears out.

Thanks to all who responded! I absolutely believe that it is cheap insurance to replace it while you have the tranny off, and that equation of cost of parts vs. misery of pulling and reinstalling transaxle is a no-brainer.

FWIW, I have a new OEM bearing on the way; I looked at the auto parts store replacement (Made by SKF, I believe), and I was appalled at the workmanship. My old OEM looked much better! To let you in on my contribution to the department of stupid tricks, long story short is I installed the new ACT release bearing I had, well, *sigh* backwards. Exit one perfectly good bearing (let me tell you, it did not go without a fight! Nastiest sound I've heard). Fortunately, I did not do significant damage to my ACT stage 2 pressure plate or street and strip clutch, so it was a relatively good outcome, and a good lesson for the engine bay that has been my classroom for the last year and a half.

Thanks again, guys!

Darrin

also while your in there its a good idea to clean off the input shaft AS MUCH AS POSSIBLE!!!!!! as well as the pivot shaft for the TOB release fork. use a bunch of brake clean and high grit sand paper/steel wool. once its all clean put a film of nice thick grease and that will make clutch release super smooth.