setting backlash on 57 Chevy rear

I have the third member pulled on my 57 Chevy car rear end and checking the backlash. I'm getting about .012 backlash and wondering how to set it. Does the crush sleeve on these rear ends determine the backlash? Also, what is the max. play you should have? I pulled the yoke to put a new pinion seal in and didn't mark the nut to know were to put it back to. Dumb*** move on my part. Any help would be appreciated. Thanks.

 

I would put a new crush sleeve in it. But that's just me.

I try to run somewhere in the neighborhood of .010 between the ring and pinion. But I have always used to sheets of newsprint roll it through it should crease the news print without tearing it.

You can get the proper torque for the pinion out of an old Chilton's find it at the local library. Shim it so that it lands in the middle of the ring gear.

That should get you going you'll have to play with it a little.

Someone else will give you the absolute best/hardest way to do it. But now at least they have something to refute.

 

What does the crush sleeve do anyway?

 

I JUST finished building a 3.08 for a fellow HAMBer's 58 Chevy.

the pinion DEPTH is adjusted by shims between the back (inside) bearing and the gear.
PINION BEARING PRELOAD is set with a combination of the crush sleeve and the pinion nut.
TURNING TORQUE is what you measure the preload by.
BACKLASH is the "slop" between the ring and pinion.

basically, you install the pinion in the case without a crush sleeve, put an inch pounds toque wrench on the pinion nut and turn the pinion. Tighten the nut until you have 15 inch pounds of turning torque.

***emble carrier, install in case.

adjust backlash by turning the adjusters in or out side for side. measure by putting a dial indicator on the edge of a ring tooth, secure pinion so it won't move, wiggle ring back and forth. move ring gear until dial indicator moves 10-15 thou. (used ring and pinion)

take a "pattern" with setup "paint"
if the pattern looks good, move on. If it's off, dis***emble everything. change pinion depth, repeat above.

once the pattern looks good, dis***emble, install crush sleeve on pinion, put it back in the case,and get ready for a fight.

it takes an estimated 300-400 pounds of torque to crush the sleeve! I fabbed a pinion wrench with a LONG handle, and used a cheater on my breaker bar, and it was a MOTHER****ER!!!!!
torque down the pinion nut until the crush sleeve crushes, check it ALOT, until you get back to the proper pinion turning torque. If you go too far you have to start over!!!

put the carrier back in, reset the backlash, make sure the carrier bearings have preload, torque the cap bolts down, adjust as necessary to achieve proper pattern

 

Moparsled has pretty much cover the essentials. One further point is that when setting up the pinion bearing preload you do that without the seal in place. You fit that at the end.

The preload on the pinion bearing is governed by the shims the nut in conjunction just holds it all together. As my trade school teach said years ago the crush sleeve stops the nut from falling off.

Given that you are replacing the seal only I would be getting a new crush sleeve and tighten it up in the usual way. As for adjusting the lash don't. Unless you have re-raced that carrier and pinion then don't touch it. Over time the lash will open up on worn gear sets. There is no point in tighening it up to the new gear lash specs. which is what is quoted in the workshop manuals. The issue will be whether or not the gear set is worn out. That would be something for the experienced eye to look at. Chipped teeth, irregular wear patterns ie galling of teeth are the sorts of things you are looking for.

 

Generally just replacing the pinion seal should not require replacing the crush collar. If you do that will involve removing the carrier except in the case of a Ford 9" which is not what you have. As has been said reseting normaly worn gears is not a good idea. I have always just replaced the seal and tightened everything back up. Since you did not mark the nut it probably won't go back to the exact spot but chances are you won't overtighten it unless you use exrtaordenary force, it takes alot of torque to further crush the collar. Just make sure it is not too loose,there may be some witness marks still visiable on the pinion threads.