What sealant to use on rear main bearing cap bolts and shims?
 

What is the recommended sealant to use on the rear main bearing cap bolts and shims? The engine is in the frame and the crankshaft is counter balanced so removal of the bearing cap is difficult. The oil leak is down from a stream to a drip at fast idle. I am going to remove the pan one more time since I over torqued the pan bolts, as per the Les Andrews book misprint, and replace the pan gasket with another new composite gasket. This is the same engine I have recently made posts about on here if you are following along with my exploits. I am gaining on the problems, not much though it seems. Thanks to all for the excellent advice!

Re: What sealant to use on rear main bearing cap bolts and shims?
 

I use nothing.

Re: What sealant to use on rear main bearing cap bolts and shims?
 

Yes, we do not use anything.

If the block and the caps were machined properly during rebuilding, they will easily compress the shims to seal un-pressurized oil from escaping.

Re: What sealant to use on rear main bearing cap bolts and shims?
 

Are you certain the leak is from the rear main cap and not the rear cam bearing?

Re: What sealant to use on rear main bearing cap bolts and shims?
 

If you're removing the pan again, you might want to make sure of the rear bearing clearance. I like to run all of them at .0015" and the rear main just a bit tighter.

And, what Dan said.

Re: What sealant to use on rear main bearing cap bolts and shims?
 

I use metric hard washers on all main bolts, I use threebond rtv sealant on the two front, center left and both rear washers on assembly..dont have to go crazy with it, a light smear will seal the washer preventing oil migration.

Re: What sealant to use on rear main bearing cap bolts and shims?
 

It is not leaking from the rear of the cam shaft. I went back together with nothing on the shims or bolts. I took out 1 peel shim on each side, .002, buttoned it all up except for the dust cover and ran it for about 10 minutes. Dry as can be! Rated right up there on the excitement scale with first time engine start from total rebuild. Adjusted the brakes last night and will be doing a carb. rebuild this weekend and front wheel bearing repack as well. It's getting close, the owner is getting anxious to drive it again. Thanks everybody for the great input, my local go to Model A guy has failing health, so I'll be back with more questions.

Re: What sealant to use on rear main bearing cap bolts and shims?
 

If you are using RTV you are doing something wrong.

Re: What sealant to use on rear main bearing cap bolts and shims?
 

Go to Antique Engine Rebuilding Website. Rich gives the total how to etc. on rear main bearing installation/troubleshooting.. bottom line is that the bearing cap surface has to perfectly match the block surface..

Re: What sealant to use on rear main bearing cap bolts and shims?
 

We put a little RTV sealer between the cork and where it meets the gasket in the chorner only and sometimes a little anarobic between the cap shims and block. Anarobic is thin enough that it should not change the clearance.