Engine Locks after Flywheel Install

[bajaman72]

My beater 1600 DP was about to get put back into the bus so I can clean the garage. The engine was running pretty good but has excessive end play. The only thing I did different was while I was installing the rear seal, I added an extra shim to help with my end play issue. Engine turns over fine until I install the flywheel and tighten. It will turn about 1/2 inch then lock up.

Any ideas what could be causing this?? I would think if it was the shim it wouldn't turn at all.

[SlowLane]

Sounds like the extra shim is locking your flywheel to the main thrust bearing (ie. the main bearing is being sandwiched between the flywheel and crankshaft). The 1/2" of rotation you're getting is the bearing turning in the case until it gets stopped by the dowel. STOP turning it in this condition, else you will certainly damage things further than they already are.

Odds are that the excessive end play you were measuring is partly (perhaps mosty) made up of play between the main thrust bearing and the case. You cannot shim your way out of this one. Colin will be sure to be along soon with words of commiseration and advice, but I strongly suspect that a new engine is in your near future.

[Amskeptic]

Sounds like the extra shim is locking your flywheel to the main thrust bearing (ie. the main bearing is being sandwiched between the flywheel and crankshaft). The 1/2" of rotation you're getting is the bearing turning in the case until it gets stopped by the dowel. STOP turning it in this condition, else you will certainly damage things further than they already are.

Odds are that the excessive end play you were measuring is partly (perhaps mostly) made up of play between the main thrust bearing and the case.
You cannot shim your way out of this one. Colin will be sure to be along soon with words of commiseration and advice, but I strongly suspect that a new engine is in your near future.

Boy, you got that right! Do not proceed.
Colin

[Amskeptic]

I added an extra shim to help with my end play issue.

It is very much not allowed to add a shim. You get to use three. Any more and you will have a chronic oil supply failure between the flywheel and shims.

I use four shims with an assembled engine ONLY AS A MOCK-UP to see if there is bearing movement between the case and the bearing.
If you can rotate the crank partially, I fear that you have a wallowed out dowel and bearing disaster.
Colin

[bajaman72]

I took the fourth shim out and the engine does the same thing. I only took it apart to scavenge the under cylinder tin for my baja. I shoulda left the damn thing alone.

[Amskeptic]

I shoulda left the damn thing alone.

Not at all.
VW's are famous for guiding their owners to the correct path.
It is merely telling you that you have this opportunity to once again make whole anew a beautiful masterpiece of ancient German engineering that you can then drive and drive, with the inestimable pride of having repaired/restored it yourself.
Colin
(with that fluff out of the way, whaddyamean that the engine is still locking up now that you have removed the 4th shim? it still clanks to a halt before you manage to get a turn out of it? Do you have open sparkplug holes, open carb top? If you get a good 300* + before it stops, and goes backwards a like amount, sounds like a piston stop)

[SlowLane]

I took the fourth shim out and the engine does the same thing.

Try pulling off the flywheel, carefully tease all the shims out, then gently rotate the crankshaft using the pulley while watching the effect on the flywheel end. Does the thrust bearing turn with the crankshaft and then stop? Do you feel resistance when it stops?

[Amskeptic]

I took the fourth shim out and the engine does the same thing.

Try pulling off the flywheel, carefully tease all the shims out, then gently rotate the crankshaft using the pulley while watching the effect on the flywheel end. Does the thrust bearing turn with the crankshaft and then stop? Do you feel resistance when it stops?

As a general rule, the investigation of bearing movement in the case saddle requires more friction than a flywheel-less crank is going to deliver. A serious thrust pressure on the pulley end may help, but this situation requires some definitive evidence.

Recommended Course Of Action.

a) before disassembly, rotate engine clockwise at pulley end until stop > give slight additional push in turning direction.
remove flywheel, mark bearing and case with sharpie
b) reassemble and rotate engine counterclockwise until stop > give slight push.
remove flywheel and see if marks are still lined up. Any movement is a fail.

I think the true course of action, if the end play was already out, is to do a nice slow winter overhaul with a weekly raid against the paycheck of about $50.00 over the next 20 weeks. Clean out the dryer and under the couch cushions for the final cost overruns.

[SlowLane]

I took the fourth shim out and the engine does the same thing.

Try pulling off the flywheel, carefully tease all the shims out, then gently rotate the crankshaft using the pulley while watching the effect on the flywheel end. Does the thrust bearing turn with the crankshaft and then stop? Do you feel resistance when it stops?

As a general rule, the investigation of bearing movement in the case saddle requires more friction than a flywheel-less crank is going to deliver. A serious thrust pressure on the pulley end may help, but this situation requires some definitive evidence.

Sorry Colin, I should have explained my thinking more clearly.
The procedure I suggested was to see if the main bearing shell and the crankshaft journal had been mashed together during the "why doesn't it turn with four shims" experiment and are now acting as s single unit. Bajaman's observation was that going back to three shims still resulted in what I presume to be the same limited range of motion. I was just trying to take the shim stack out of the equation entirely.

[kreemoweet]

Has a jammed-up distributor drive pinion been ruled out?

[bajaman72]

Dont think its the shims, dizzy never came out either. Metal shavings behind the flywheel make me think it's time to shoot it.

[Amskeptic]

Dont think its the shims, dizzy never came out either. Metal shavings behind the flywheel make me think it's time to operate.

[bajaman72]

If I remember correctly the case is line bored 40 over. Didn't think it could go more than that. With the end play as well I figured the case would be pounded out.

[SlowLane]

It sounds as if it doesn't owe you anything.

Give it a Viking funeral. Build a raft, light it up with a flare and put 'er out to sea. Magnesium burn real good.

But keep an eye out for the heat.

[bajaman72]

You're absolutely correct. It doesn't owe me anything. I'll have the case checked before it goes into the fire pit.