Seriously folks. What exactly DOES this oversized copper/brass washer do for us? Does it rotate freely? Is it just a guide/bumper for the tranny input shaft? What happens when it fails to do what its supposed to do?

I'm looking at mine right now, eyeballs on the darn thing, and just can't figure out its mechanical significance.

Somebody set me straight, or else the old one stays in. :p

I learned something too........



Description: The pilot bearing sits in a hole at the end of the engine?s crankshaft. Pilot bearings have three different designs: 1) roller bearing, 2) needle bearing, and 3) bronze bushing, which is actually more of bronze sleeve than a bearing. The bronze bushing and needle bearing are most common.


Purpose: The main purpose of the pilot bearing is to provide a low-friction support for the end of the transmission?s input shaft.

Maintenance Tips/Suggestions: The pilot bearing does not require routine maintenance, but should be replaced when clutch replacement becomes necessary. In some cases, pilot bearings can wear excessively when transmission-mounting bolts loosen. When this happens, the transmission?s input shaft moves around excessively and puts abnormal strain on the pilot bearing. If you suspect a problem with the pilot bearing or clutch, have it looked at immediately by a qualified technician. Putting it off will only make the problem worse.

Kel

John,

I guess you are asking about the brass pilot bushing in the rear of the crankshaft. My engine uses a roller bearing for the input shaft. If your's uses a pilot bushing, then go ahead and replace it. It keeps the input shaft aligned to the rear of the crankshaft and you don't want to run without it.

Tom

John,

I would suggest replacement. The front bearing in the transmission will see increased wear if this bushing is excessively worn. Do you have the means to measure the bushing id and compare against the pilot portion of the imput shaft?

The "washer like" description you explained to me the other evening does not sound like a pilot bushing. Some quick research shows stock bushing was 1.094" OD x .592" ID. No length was given however if I remember right these bushings are about 7/8" long. This is a stock replacement bushing for all '67-81 V8's except 256's

According to the same parts catalog there is also a roller bearing offered that fits '67-'79 V8's. It is 1.379" OD x .590" ID x .390" thick. I can only assume there are two different bores in the end of the cranks that would accept either of these bearings.

Were you able to remove the old bearing?

How about a couple pics of your crank and your new bushing so we can see what your seeing?

The pilot bearing keeps the transmission shaft concentric with the clutch. It keeps the transmission shaft spinning on the exact centerline as the crankshaft.

If the bearing is worn, the transmission shaft can shift off-center during engagement with the resulting wobble causing clutch chatter and vibration. The bearing in my 1968/3 speed was a ball bearing type. The bearing in my slant six mopar was a brass sleeve.

The bearing is inexpensive enough compared to the labor involved to replace it later, that it is recommended to replace it any time the clutch requires replacment.

In all the highly technical help above, they may not have answered your basic question. With the clutch pedal out (clutch engaged) the crank and trany shaft are spinning at the same speed so that pilot bearing isn't really doing anything. The only time that thing works is when you push down the clutch. Then the crank is still spinning and the tranny shaft is stopped. If it fails, it might jam up and you wont be able to shift because the tranny shaft will still be spinning with the crank.

I'll post pics tonight.

Bob S put it best. 68 Blkbrd and Tom Jr. together also hit the nail on the head, too: Replace it, and don't leave home without it.

To remove it, an internal race bearing puller (borrowed from an auto parts store) is one of the few tools that will do the job while it's in the car.

You have a pilot bushing. Replace it with a pilot bearing. Dennis gave you that one.

Nash,
You've got good info here. Use it.
Before I get too deep however, if this thich WASHER (bushing) rotates FREELY in the back of the crankshaft, you may have other issues...
I was always under the impression Pontiacs came out with a bearing for the pilot anyway. Most of the clutch kits come with a bushing. Usually acceptible, but I whole heartedly agree with PMI to replace with the proper bearing. BCA (& industry) Part #7109. It is a single row ball (rather than roller) bearing assembly that is shielded on one side. Should be available at any parts store. There are many methods of getting the old one out. They make pullers that may be available through parts house tool rental programs.

Here is what came with the clutch kit:



Here is more like what I have currently installed, with what looks like inner/outer races.



And here is me, getting pretty pissed off and needing the strait-jacket at this point!!

:p

Well Nash,
If that is pissed OFF, I'd hate to see you happy.
The bearing style is what I personally would use.
Greg

Here's an installed pilot bearing. This one is the one from the factory.

Toss that washer off to the side...

Rent a slide hammer to pop what ever is currently in your crank then replace it with either a proper ball bearing or bronze bushing.

Remember... The slide hammer is our friend

Got the old one out tonight with the "slide hammer" method. Popped right out after letting her soak in nut-buster for 30 minutes. Its what I'd call a roller bearing. 8-10 balls I'd say. Seems to be in perfect condition but I'll replace.

So, I'll put this new copper/brass washer-from-hell on the shelf and order the new bearing type in the morning. Thank you, all my friends. Not quite done, but pretty close.