pop23235

Setting up my rear spindle/bearings. Tolerance/set up is +0.001" to +0.007". Shims are available in 0.006" increments. Mine are checking out at or less than 0.001" clearance, so I need to shim either to 0.007" or leave as is. One measures just less than 0.001". The other seems less, but the 0.132" shim shows some wear (~0.001") so replacing it with a 0.133" shim should put it right at +0.001" clear.

So which is better? Tight at 0.001" or loose at 0.007" given the choice?

Of course, I could take a little off a larger shim to get under the 0.007".

Looking for experienced advice, please.

OH, this is a 64 w/drum brakes FWIW.

Plasticman

I always set mine up at .001" (per John Greenwood's recommendation).

Never did understand why the large range.

I guess the shim selection was larger back then (1970's).

Plasticman

427Hotrod

I set mine at .0005" (less than .001").

JIM

Boyan

I had a problem once with a .001 set up. Had to re do it as it was acting up. So now I shoot for 2-3 thou and have never had an issue. I wouldn't go more than .003. Try switching the spacers around or if you have access to different spacers , measure them and see if you can get your tolerence that way.

Boyan

And unless you have a surface grinder and ability to re-harden shims, I would not alter the thickness of any shim. What size do you need? I will look through my stack.

Boyan

Missed it. I will look for .133

pop23235

By switching shims (0.127" and 0.133") I have one set up at 0.004". I think this is better than before as I think it had bearings preloaded. A 0.133" should make the remaining one about 0.002". Thanks for checking Boyan! Hope you find one.

Boyan

I dont have that size. Try Duntov Motors. They have checked their stock for a specific size for me in the past.

rene-paul

My 2$... From what I understand the theory behind the tighter end float is to minimise the potential of the rotor moving in and out causing "pumping" of air past the caliper piston seal and getting into the brake fluid thus causing spongy pedal. We who have drum brakes do not fall into this category. I have seen the engineering specs .001 to .007 and .002 to .008.
I run mine loose at approx .006. The set up of tapered rollers is a study in and of itself;
Engineering wise. Case in point, the pinion tapered rollers in the carrier are set by rotational torque using a crush sleeve. The rear spindle tapered rollers are set by end float using shims. [.001-.007 or .002-.008].

Critter1

It's actually best to set the clearance at around .002-.003" instead of shooting for .001".

Tapered roller bearings need a small clearance to relubricate the rollers.

Tapered bearings in 90W lube can run at zero end play because the oil relubricates the rollers constantly.

pop23235

Thanks for the comradery, but some days you should just not get up.
Did all the dry (light oil) checks to get the 0.004" or 0.005" clearance, both bearing felt really smooth and normal even though the inner race looked just "off" a little. Not bad, just different from normal. Smooth as butter though. So, I greased both, installed the new seals and figured it would read 0.003" when lubed or a little more. Got all together with the backing plate and trailing arm and torqued the retainer nut. Did a final check and noticed the inner had a roughness not felt before. Clearance went up to 0.006". Unless Valvoline puts rocks in their wheel grease, I'm puzzled. But I know I've got to change a bearing and start all over. :-( Only thing I can think is the bearing had been run too tight and wore a groove not visible on the race. Once loosened a few thousanths the roller is not running the exact same grove. Think I'll take a break!

pop23235

Thanks Boyan. We'll see where we go. New bearing could be lots different. I may just buy an assortment from ZIP on Monday.

Plasticman

Critter1,

Like I said, I set mine in my 70 Vette at .001". I also cut the spindles down to slip fit the inner bearings, so I could adjust the clearance perfectly (all per John Greenwood). That was at about 66K miles for both sides. I drove that Vette daily for a total of 247K miles (over 15 years), without ever needing to take them back apart, so I guess that I (and Greenwood) must of done something right.

I have always been a fan of synthetic EP grease, but I honestly can't say what grease I used in those bearing back then.....mid 1970's

And the rear wheel bearing spec in 1970 was .001" to .008" endplay.

Plasticman