jjs3rd914

Anyone ever seen this before, if so what happened?

We are rebuilding a 1972 1.7L. Upon removing the main bearing by the flywheel, the one that is suppose to set the crank end play, the rear flange was gone. It almost looks as it someone had machined off the rear flange! The crank end play must have been huge! What is amazing in the car fine and there was no noticeable indications of any issues. We did not see any chunks of metal when the case was split. We suspect the machining has been going on for quite some time and the filter was capturing the debris.

It also appears that the #3,#4 main bearing webs in the case were in part of acting as the thrust surface with the crank throws slightly rubbing (machining) the webs. There were only two shims found each .011 thick. No remnants of the expected third shim was found. The shim closest to the bearing was rolled a little on the inside. We did a stupid thing by not measuring the end play before disassembly. Also the locator hole on the bearing was found to be elongated.

Another thing we found was the clutch TO bearing was missing both of the curved plastic end spacers. The bearing must have been floating back and forth in the fork. There was no evidence they were ever installed the last time the motor was out as no remnants were found inside the bell housing. We have only driven this car a few hundred miles since purchase. We wonder if the fact these were missing contributed to the disintegration of the main bearing.

It does not look like there is any permanent damage although as expected the flywheel side of the rear bearing race is chewed up a little but the new bearing fits snug.

Anyone have any thought as to what happened here?

One theory from another forum suggested a prior owner had the clutch and flywheel replaced and the mechanic did not know to check the end play?

Thanks
jjs3rd914

Geoff

Yes, the last guy didn't know how to set the end play and choose not to use 3 shims which ground down the bearing. I doubt the lack of the plastic ends did anything it just makes it harder to shift.

Matt Romanowski

The actual number of shims doesn't matter. The only important part is that the endplay is correct. Without seeing everything as it came apart, it's hard to tell, but I would think that the motor would have been incredibly noisy with that much end play. With the combo of end play and throw out bearing, I would expect you to get some serious noise and chatter on engaging and disengaging the clutch.

The only thing to do now is rebuild it correctly.

Matt

Geoff

As I understand it the 3 shims work together to prevent wear on the bearing and flywheel. Adding more or subtracting can result in damage.

Where did you hear it doesn't matter???

Matt Romanowski

When you set endplay, you are setting the distance that the crank asembly can move fore / aft in the case. The crank journal that controls end thrust is wider than the bearing by some arbitrary amount that changes depending on how the crank was manufactured (grinding, wear, etc). The shims take up the extra space and move it into a predefined acceptable amount. Depending on your crank, case and bearings, the amount of space you have to take up changes. As the measurement changes, the number and thickness of shims changes.

I think what is confusing you is that most of the time there are three shims and people just put the same number back. This is ok 90% of the time, but you should always measure.

Matt

jjs3rd914

We have done a preliminary spot check on the end play. We installed 3 shims, 2 x .0126 and 1 x .0094 for a total of about .034 and we still have about .010 of end play and want a target of .003.

The manual says to install only 3 shims. Shims come in .0094, .0118, and .0126, .0134, .0142, and .0150. So it looks like we need to buy some thicker shims. Does this end play measurement seem in the ball park? It seems that we are on the high side on the thickness of shims required and will need 2 x .015 and 1 x .0126. We are going to have to get 2 of the .015 shims unless it is permissible to use 4 shims. Any thoughts on using 4 and where can I find the .015 shims?

Thanks,

Jeff

Thanks to all for helping unravel this mystery.

Jeff

Matt Romanowski

I wouldn't get excited about using 4. I've done it in the past without any problems. As far as buying shims, I'm not sure.

Matt

Geoff

You can order them from VW or Jake Raby with Jake being faster. Always use new shims as they do wear are get dished.