ShopTalk Forums | Aircooled VW Tech & Restoration Help

I put the flywheel on my crank(with rods) and got it as tight as I could on my workbench and took an endplay measurement between the rear main bearing and the flywheel with feeler guages and it came out to be 0.049 in. From what I've read in other posts, I should use 600 grit sandpaper to take material off the front side(not flywheel side) of the rear main bearing. Then I was thinking about it and I looked at my #3 main bearing and took endplay there(I guess its not really "endplay") but it has 0.145 in. of movement in it. So whats the point of setting endplay at the rear main bearing when its got more slop in the #3 bearing?

Thanks,
Andy

Hmmm, something doesn't sound right to me. Isn't endplay the amount that the crank can move axially? How can it move more when measured at a different spot?

Steve

Andy:

The procedure for setting end play is outlined in the VW manuals,
or a VW restoration manual. However I would think that you may not
have access to one (Would be a good idea!)

To answer your question "end Play" is actually measured on the exterior
of the engine, after secured Flywheel; the measurement is between the flywheel and Engine Case when the crank / flywheel is moved or flexed back and forth (using a Dial indicator to take the measurement). What it confirms is the maximium clearance or movement of the crank (back and forth) within the engine bearings (or case). At the # 4 or rear bearing, when this is done properly the crank can only move based on clearance
at the rear bearing. Don't worry about the other bearings and their potential end play since it has nothing to do with the actual rear
end play.

This is usually checked once the short block is together and torques set.
I am not sure if you could check this without it being together by using a feeler guage; I would not suggest it.

Once you do the preliminary check (which manuals suggest to use TWO
shims) then take an accurate measurement; then based on your
measurement and the "clearance required" then subtract it and you
will know what size shim or combination of shims is needed to arrive at
the final clearence. (The manual also states you must use a total of
three shims)

Have fun and trust this helps out. Otherwise stay tuned and an expert
should reply and further steer you in the right direction. Good Luck.

Allan

Yeah, I guess the crank can only move axially as much as one(only one) bearing will allow...in this case the rear main bearing.
The way I understand it, is I do a preliminary check with the crank and flywheel on a bench. Slide feeler gauges through the gap between the rear main bearing and crank to find the endplay. Then use 3 shims to make that endplay reduce to 0.003-0.005". Once its all in, then I double check the endplay with a dial indicator as you mentioned. I don't see anything wrong with doing it this way?

Thanks,
Andy

Mugsy wrote: Then use 3 shims to make that endplay reduce to 0.003-0.005". Once its all in, then I double check the endplay with a dial indicator as you mentioned. I don't see anything wrong with doing it this way?

Sounds good. By checking it before you install the crank you'll know early-on if a little machinework is going to be needed to the crank or 'wheel, too (rather than discover that you can't get it right with the recommended three shims after the shortblock is almost done). Beware of flywheel flex making your dial indicator reading higher than the actual endplay - clunking the crank back and forth from the other end will eliminate that concern. The factory minimum of .0027" is a little tight for my tastes, shoot for .004" and try to stay within half a thousandth of that for a final reading.

Whoa, I screwed up somewhere! Ok, let me go through this whole thing again. I started off with 0.049" endplay with no shims installed. The minimum endplay I would need would be 0.081"(0.024+0.024+0.030 shims + 0.003 real endplay = 0.081"). I just happened to shave the right amount off my rear main journal so my enplay was in fact 0.081". So I put on the 3 shims I mentioned(2X0.024 and 1X0.030) and the endplay ended up being 0.045"!!! So then I put on the biggest shims I've got: 2X0.036 and 1X0.034...and then the endplay was 0.033"!!! What gives? I obviously screwed up bad somewhere, but I'm not sure where. Any suggestions? I supposed I could throw on a 0.030 shim and have 0.003" endplay...but is it wrong to use 4 shims? I feel like such an idiot!

Thanks,
Andy

AGH! I figured it out...the shims are 0.24, 0.30, etc. MILLIMETERS...I was thinking 0.024, 0.030 INCHES! Not only was I wrong on standard-metric, but I was off on a decimal spot too. No wonder none of my calculatioins worked out. I definetely screwed up. So I actually had 1.245 mm of endplay with no shims...and using .36+.36+.34mm shims I'd have 1.06 mm worth of shim which would leave me with 0.192mm, or 0.00756" endplay....so I still would have to use a fourth shim anyway.

Now I have 2.057mm of endplay without shims, so I'll need to get a new rear main bearing. Anybody got a spare they'd be willing to sell to me?

Andy

What size bearing do you need?
http://www.1800vw.bizhosting.com/mainbearingList.htm
You may not feel comfortable with doing this, but I see no reason why it should cause a problem: the endplay shims made for non-O-ring cranks have a larger ID and will slide over the main journal (one should never use these for an O-ring crank) but in this case using one thick one between the crank & the #1 main bearing would bring things back to "normal".

Could I use a bunch of my shims to get the proper endplay just for mocking up...until I get a new rear main bearing? Any reason why I shouldn't do this?

Thanks,
Andy

If you do, the crank will be pulled slightly further to the flywheel end which could be misleading as regards any clearancing you may need, but it shouldn't hurt anything otherwise. Shouldn't be enough to cause any problems with the distributor drive pinion mesh, for example.

Marc, I'm sorry but I don't understand why the crank would be pulled towards the flywheel. Is there a difference between main bearing material and shims(they both take up space)? The real question is, would this alter my deck height readings, or my cam gear meash?

Thanks,
Andy

Didn't you say that you'd removed some material from the inside face of the thrust bearing? If so and you make up for it with shims on the outside (flywheel) side, the crank is going to ride a little closer to the flywheel end - that's why I proposed using one early large-ID shim on the inside of the bearing. Sounds like you're only talking about ~.012" so it shouldn't affect anything dramatically.

Hello all, I got my new rear main bearing in today and I put it on and checked the enplay. It was 0.050 in.(1.27mm) without shims. If I put on my biggest shims: 0.36+0.36+0.34=1.06mm, that would leave me with 0.21mm of enplay which is equivalent to 0.008" endplay! So...should I add a fourth?

Thanks,
Andy

Okay, I put on the three biggest shims: 0.36, 0.36 and 0.34 and the endplay(with feeler gauges) was in fact 0.004". I suppose its possible I'm doing something wrong...for instance, I have the flywheel/crank assembly on its side...maybe I should have it standing on the flywheel as a base? Either way, I'll double/triple check it with a dial guage once I put the crank/flywheel in.

Thanks,
Andy