12 bolt help
 

Anybody have a tip or trick for not over tightening the crush sleeve


Scott

Re: 12 bolt help
 

Are you assembling with a new sleeve or are you just replacing a pinion seal and re-tightening?

My experience is it takes a 4’ cheater bar to crush a new sleeve and something equal to hold the yoke if assembling a diff. I use my IR 1/2” impact to crush new ones usually. Sometimes the hammering doesn’t work as it just loads and unloads but doesn’t crush the sleeve. That’s when a cheater comes in.

When replacing a pinion seal I use a 1/2” ratchet and just get it as tight as I can. I’ve never seen it add to crush.

If you are doing the latter, I recommend a new pinion nut.

Re: 12 bolt help
 

Complete rebuild, new everything 3.73 plus a posi unit.. thanks for the help

Re: 12 bolt help
 

I do the same as Mike C... run it in with a 1/2" impact. I stop frequently and check the preload until it gets exactly where I want it. It takes somewhere around 3-400 ft lbs to even start to crush one, so I've never had an issue with over crushing one as long as I check the preload frequently as I'm tightening it up.

Re: 12 bolt help
 

I just did mine I did it in the truck used a big pipe wrench to hold the yoke it was long enough to go over to the trailing arm . then used a half inch rachet with a piece of pipe to make the handle longer and just kept tightening it till it didn't rock in the races anymore . when it started getting close I kept an eye on the socket so I didn't turn any more than an 1/8 inch at a time till it got the right rotational torque . was way easier than I thought

Re: 12 bolt help
 

Sounds good guys. L
I'll probably shortcut it and pre crush it on a press at work, figure I'll get to .030 of the original and the finish it in the rear end

Re: 12 bolt help
 

My pinion bearings under preload are not smooth. Is this normal? Thanks

Re: 12 bolt help
 

I have personally had no luck with impacts. When you are close there just isn't the control you need when using an impact. I can almost guarantee you will end up over tightening the pinion and your preload will be too high.
I use an extra long SnapOn breaker bar with a cheater on it.
I back up the pinion with a pinion wrench but there is no reason a large pipe wrench wouldn't work. I just can't have teeth marks on customers pinion yolks. Adapting a typical 1-5/16 socket to a 1/4" square drive inch pound torque wrench is always and issue. Preplan for this or you will end up guessing on the torque.

My pinion bearings under preload are not smooth. Is this normal
Can be but, but guessing by your description the nut may be over tightened? What is the turning torque when this is an issue?
Typically you have a brake away torque and turning torque. This is why you need to use a dial type torque wrench for this job.
Rick

Re: 12 bolt help
 

Probably. Well lubed and broke in they'll be smooth

Re: 12 bolt help
 

Go get a inch pound torque wrench and don't guess.

You will be surprised how much crush is needed to get you into spec.

Do not Pre-Crush the sleeve. If you cannot get the resources to set it up right, then find someone who does.

This is an area that you do not want to guess. I have seen it, you don't want to experience it. You put too much money into it to not finish it correctly.

Smitty

Re: 12 bolt help
 

New bearings installed correctly under preload will not turn smooth. They are supposed to have a drag.

Smitty

Re: 12 bolt help
 

The turning torque required should be fairly smooth. One can see this on the torque wrench needle as it's rotated. In my experience if torque needed to rotate the pinion raises and drops significantly, after the pinion is turning, the preload is too high. But you are the judge on that, I am not on site.

Re: 12 bolt help
 

Go to posting numbers 558 to 574, in the link below. It shows how I did it utilizing a jack to slowly crush the sleeve. Starting on page 23 I believe.
Gary

http://67-72chevytrucks.com/vboard/s...d.php?t=259859

Re: 12 bolt help
 

if the sleeve is a lot longer than the original, i would not 'pre-crush it'. The bulged part of the sleeve really only works like a spring for so many thousandths of an inch...then it humps up in the middle and won't act like a spring any more. If that makes sense.

if it's too long, then I'd grind off some material squarely from the ends. Keep the bulge part in the center in tact for when you crush it down. The crush sleeve has a working range basically...you can tell if you crush past that point as it will get a LOT easier to turn the breaker bar

Re: 12 bolt help
 

You could use a 12 bolt crush sleeve eliminator

Here is one from Dennys for example

https://www.dennysdriveshaft.com/p87...olt_truck.html

Re: 12 bolt help
 

The crush sleeve eliminators are a good idea. They allow you to tighten the nut enough to add some additional axial force to assist in retaining the bearing during high loads. The disadvantage is getting the preload correct requires removing the bearing, possible more than once. If I was going to use crush sleeve eliminator I would install the crush sleeve to get my preload and then measure the length of the sleeve. Then use the measurement as a starting point on my shim stack. Of course this would eliminate any assembly advantage of the shim stack.

Setting up your first differential is a daunting task for the newbie.

When working on your differential you will need a wide variety of tools. Using the correct tools saves time and helps prevent parts from being damaged. Here is a list of some of the tools that you may find handy:

Dial indicator

Gear marking compound and a brush

Calipers or a micrometer (to measure shims)

Bearing pullers

Bearing press

Three foot long breaker bar or strong impact gun

Pinion nut socket (often 1-5/16")

Ring gear bolt socket

Carrier cap bolt socket

5/16” Six point cross pin bolt wrench

Pry bars for removing the carrier case

Ball pein hammer

48 oz plastic dead blow hammer

Center Punch for marking carrier caps

Oil drain pan

Foot pounds torque wrench

0-50 Inch pound torque wrench with reverse adapters to attach to pinion nut.

A beam style torque wrench for torquing the LH ring gear bolts.