Type 4 End Play Shims?

[mentalQtip]

Guys. measured crankshaft end play at 47+ thousandths without any shims. Minus the 3-5 thousandths leaves 42 to 44. I'm figuring three of the .36mm(14 thousandths in.) would equal .042 in. I'm trying to find shims and the local places say not available. Where does one source these shims?
I see that type 1 shims all freely found but not for a late bus.

Thanks

[ruckman101]

Running a type 1 engine. Halsey had shims for me.


neal

[tristessa]

I think Paige got some at Halsey for her engine build .. there or whatever-Dan-Hall's-is-called-now.

[mentalQtip]

Halsey said not available. I'll try "Dan Hall's" on Monday.
ll

[drober23]

Wait till Tuesday

[mentalQtip]

Will do.

[sailorkh]

This guy still has some .36mm shims

http://www.thesamba.com/vw/classifieds/ ... id=1331521

[SlowLane]

Colin and I had an interesting discussion on end-play while he was here. He explained how it is possible to get too little end-play with an apparently correct stack of shims calculated from the no-shim measurement. The problem is that the no-shim measurement actually has two components in it: the actual free play between the crank/flywheel (which is what we are aiming to adjust) and the amount of play between the case bore and the #1 main bearing thrust surfaces.

In an ideal world this second parameter woud be zero, but few of us live in that world. So to factor out the bearing-to-case play (and to check that it isn't excessive, indicating a rebuild is in order), we need to measure it somehow.

As usual, Colin had the answer. The technique is to stack up more shims than are necessary to make up the measured end-play and snug the flywheel down (but not fully torqued. Just enough to take out the slop). You then measure the end-play as per normal, except you DON'T rotate the crank/flywheel assembly. The #1 main bearing is clamped between the crank and flywheel at this point, like in a vise. Any attempt to rotate the flywheel will try to spin the bearing in the case. That's a no-no.

So, once you have the bearing-to-case thrust clearance (and hope it's either zero or negligible), subtract that from the no-shim measurement you had made previously. Then use that new value to calcuate your desired shim stack.

[Amskeptic]

Colin and I had an interesting discussion on end-play while he was here.

. . . like how my shim inventory has slowly migrated from nice and thick 35s and 38s and even a 39 to a pile of useless skinny 23s and 25s. Now what am I going to do? We need to bond some skinny ones together absolutely shear safe.
ColinIAin'tSkinnyThough

[mentalQtip]

Hmmm. Why is it that I don't remember reading about this "rotation" part of the end play measurement. Is there a "how to" section I missed?
Reading the above, do I just stack shims to more than my 47 thousandths and snug up the flywheel and rotate the flywheel and then try to detect any end play? That simple? What amount of movement would be too much and point to an engine rebuild?

Thanks

[Amskeptic]

Hmmm. Why is it that I don't remember reading about this "rotation" part of the end play measurement. Is there a "how to" section I missed?
Reading the above, do I just stack shims to more than my 47 thousandths and snug up the flywheel and rotate the flywheel and then try to detect any end play? That simple? What amount of movement would be too much and point to an engine rebuild?

Thanks

If you do add a fourth shim to check for bearing movement that might screw up your end play math, **do not rotate the engine with the fourth shim installed*, that's all. Any movement of the bearing is indicative of problems, it is all a gamble after that. Do not ride the clutch!
Colin

[mentalQtip]

So I shouldn't try the extra shims. Remember who your talking to. "Mind to mush".
If I add shims to more than my end play without shims, then still have end play, then I have a #1 bearing problem?
What is this part about turning the flyiwheel when checking end play?
Confused.

Joseph

[SlowLane]

When checking the end-play the normal way (ie. without four shims installed) you are supposed to take measurements at several crankshaft rotation angles, looking for the "tightest" spot. That is, the one with the least amount of end play. Then you use that value to calculate your shim stack. This is to ensure that you don't inadvertently calculate too thick a shim stack based on one single measurement which is not the "tightest".

Given your evident confusion, I apologize for bringing up the four-shim stack measurement. It isn't one that an average mechanic would even think of doing (but we are talking about Colin here). As usual, his is the best advice to follow here.

[SlowLane]

. . . like how my shim inventory has slowly migrated from nice and thick 35s and 38s and even a 39 to a pile of useless skinny 23s and 25s. Now what am I going to do? We need to bond some skinny ones together absolutely shear safe.

So I've always wondered why three shims is the magic number? What harm would result in using, for example, four .025" shims instead of three 0.033" shims?

[Amskeptic]

. . . like how my shim inventory has slowly migrated from nice and thick 35s and 38s and even a 39 to a pile of useless skinny 23s and 25s. Now what am I going to do? We need to bond some skinny ones together absolutely shear safe.

So I've always wondered why three shims is the magic number? What harm would result in using, for example, four .025" shims instead of three 0.033" shims?

Oil delivery . . . four shims and oil does not reach the flywheel thrust surface in quantity required.
Shear . . . less than three shims will rip the oil film at high rpm. Each shim serves as a "bearing" between the 4,000 rpm flywheel and the stationary #1 bearing.

As ever, rocks and hard places abound.
Colin