Isuzu SUV Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
13,615 Posts
Discussion Starter · #1 ·


I just disassembled an Isuzu 12 bolt rear third member, so I figured this was a good time to compare and inform...
The pinion shaft with the elongated sleeve is the 12 bolt ,and the other with the shorty is a Dana 44... Generally speaking these are a one time usage, and anytime you pull the yoke your taking a risk of messing up the pre-load..!! There are ways around re-use... Taking a small ball peen hammer and tapping around the flared part grows/expands it a bit, for retorqueing purposes... Another way is to add a shim between the upper pinion bearing and sleeve/collar ... If someone pulls there yoke to replace the seal this should be considered... What can happen ??? Worn bearing allow for a bit of compression on the already used sleeve and you can tend to over load the preload which can take out the whole assembly.. Very bad !! Or it looses it's torque load and the pinion can start walking forward and backwards, that messes up the backlash and can allow the pinion to actually dig into the carrier as its turning..!! Just an FYI I figured I'd put out there...
Setting them really isn't that hard, you tighten down the pinion and spin it occasionally to feel the drag /preload... It's similar to wheel bearing torque /preload in a sense... If you end up going with a new crush sleeve , don't be surprised if it has a good 1/4" of play before it starts to crush down !!! And it is hard to get the nut to spun at first probly 200 plus ftlbs of torque to break that initial crush...
 

·
Registered
Joined
·
8,073 Posts
Thanks...I may possibly be dealing with this soon.
 

·
Registered
Joined
·
13,615 Posts
Discussion Starter · #4 ·
You could possibly get one or make one, it's not a big deal to put in a shim.. Say 20 thou that's all you really need.. It just has to clear the bearing cage so it doesn't frag... The 44 would be easier to come up with a solid piece as apossed to the sleeve , but you'll have to assemble it and check preload the disassemble to add subtract ... The crush sleeve does have its advantages there...!! You load the front bearing and seal (prelubed) then insert the pinion with the rear bearing and crush sleeve through the works, then put the yoke on and start to suck it down (set preload ).. I've done both and it's a little more time consuming to assemble, check adjust, assemble test , then do the final assembly... I usually leave the pinion seal out till its right... I've messed up a few in the past lol or a shim slips inside and you gotta go diggin... I also cheat and use air on the nut.. Works great for doing a crush sleeve setup.. Buzz it down while stopping to spin (check preload ) then when you get close just quick blapps with the air gun and done deal... I've been under a truck before with a big breaker bar and a pipe wrench holding the yoke from spinning, I can tell ya it ain't fun...
 

·
Registered
Joined
·
1,018 Posts
So you're saying pinion pre-load can sort of be winged (so to speak) comparatively to wheel bearings? I normally just seat and spin the wheel bearings and then give them a "good enough" tightening and I've never had problems. I just thought that pinion pre-load had to be a little more precise.
 

·
Registered
Joined
·
996 Posts
I am in the middle of this too and I can tell you that the crush sleeve wouldn't crush with well over 200 ft/lbs. Randy's ring and pinion says its in the 300-400ft/lbs. Only a very good impact will do it. I am going to need a cheater pipe on my breaker bar to make it work. i did try to get it started in my shop press and the press plate broke. However, I decided to see if I can figure out a good option for the solid spacer, so hence a break and a little research. No luck yet though. I did try in the past to use a shim on a crush collar and due to the wall thickness being fairly thin on the crush collar, the shim wouldn't stay aligned and it never wanted to work right.

One thing I'm considering doing though is adding an oil slinger that Isuzu doesn't seem to use to increase lubrication on steep slopes, angles. Anyone tried this?
 

·
Registered
Joined
·
13,615 Posts
Discussion Starter · #7 ·
I was using the wheel bearing comparison as an example.. Bearing load (the resistance to spin the pinion) is very similar though.. 5-8 lbs of pullin force to rotate the pinion, and it can stick when it's all new... Once you spin it a few revolutions the lube makes it a bit easier... I have tons of shim stock in a can that Ive saved from various rebuilds, it comes in handy..
I remember doing the Dana 44 rear axle for my buddy's amigo a few years back... I stripped the nut tips off because I used a 12 point socket... Ended up buying a good 6 point and changing the nut.. But it took a lot of torque to sintch down... I used the 3/4" air gun too... Once it starts to squish it does get easier , make sure and lube the nut and threads... I think the housing has a nice opening for the ring gear to shoot the oil up to the pinion bearings doesn't it ?? There's also a pocket in there that holds oil.. It a place that needs to be cleaned and checked if you ever blow gears !!
A piece of Dom would work but you'll need a few shims... Couple 2 thou 5's and 10's what ever you can muster up...
I spose (not recommended) you could bang the new sleeve a few times to initialize its movement,then assemble... That's a worst case no other choice, stuck on the highway method...
 

·
Registered
Joined
·
996 Posts
I am looking for shims for my 12 bolt right now and will then on the 10 bolt. I discovered that the Toyota 8 inch 4 cylinder differential uses the same pinion shims as the Isuzu 12 bolt. Do you know of any interchange on shims for the side bearings?

And yes, a 3/4" air gun with good shop compressor would really aid in the job.
 

·
Registered
Joined
·
1,018 Posts
bradzuzu said:
There are ways around re-use... Taking a small ball peen hammer and tapping around the flared part grows/expands it a bit, for retorqueing purposes... Another way is to add a shim between the upper pinion bearing and sleeve/collar ... If someone pulls there yoke to replace the seal this should be considered...
I'm guessing I'm just not reading this quite right, but which option should be considered? Or do you mean both? I guess the part I really don't understand is the purpose or reasoning behind adding the shim between the upper bearing and crush sleeve. Would a shim make that much of a difference?
 

·
Registered
Joined
·
996 Posts
Shims make a huge difference. When you set up a differential, thousandths of an inch make big differences. Typically, when a pinion seal is replaced, shops mark the pinion nut and retighten to that exact point on reassembly.
 

·
Registered
Joined
·
1,018 Posts
I understand the point of shimming the pinion and the carrier in a differential, but from what brad said I was under the impression that this shim would be specifically placed there to reuse the crush sleeve. I guess what I'm trying to understand is would you be able to achieve the same preload on a reused crush sleeve simply by adding shims?
 

·
Registered
Joined
·
996 Posts
yes you can
 

·
Registered
Joined
·
13,615 Posts
Discussion Starter · #14 ·
Yah a new crush sleeve is the best plan of attack... But if your doing a pinion seal that's leaking really bad type of job, then you could get away with pulling the yoke, pulling the seal, then get the front bearing out (good chance to inspect and get an idea of bearing wear) then throw in a shim and reload your pieces (including the seal) then re-torque the nut... It will be a bit more tricky to gage the load... With the tires off the ground (maybe romved) spin the yoke and get a feel for resistance, then disassemble... As your redoing the final preload it should feel just slighty tighter then before... It would be best to remove the tires and calipers so you can get the best feel for what's going on... If your nervous still or unsure then you can pull the axles, back cover or whole third member and remove the carrier... Once your all done take a ready drive, say 15-20 miles then go put your hand on the diff housing... Should be warm but not hot... To much preload will cause to much friction and heat... Most shops should have a variety of shim stock on hand from doing axle rebuilds, I've hit those places up many a time to get the right size shims...

When replacing all the bearings you can general reuse the shims that set the pinion depth (typically one or two behind the race/bearing cone) if you screw them up pounding out the race just stack them together in your hand and measure them... Then just use the equivalent of new ones... The carrier sometimes works out that way to... Bearings are fairly precise within 1-3 thou (plus being new) will fit tighter... So you can start that way with your base setup... I prefer third members that take shims on the outside of the bearing cups, less chance of screwing up the new bearings on the carrier(off/on)... Even better the diff's that have threaded screw caps (toy and 14 bolts) ...
If your changing carriers ,the pinion still can be left alone in most case (the center line circumference hasn't changed) you'll have to set the backlash is all...
 

·
Registered
Joined
·
7,076 Posts
A solid spacer is a preferable design when your setting things up brand new. Once you have the right spacer its done forever. One could easily be made by a machine shop. Have it made .020" short and use shims to fine tune. If your servicing an axle you will have to do this on a bench with an inch pound torque meter. If your doing a D44 then there are probably a hundred different sources for a solid spacer.
 

·
Registered
Joined
·
13,615 Posts
Discussion Starter · #16 ·
I know the standard 44's just take shims, atleast my front axle did... I'm not sure about the early 44's in the rodeos though ... Anyone know that answer ??
 

·
Registered
Joined
·
7,076 Posts
Yup most D44's use a shim stack and spacer but as far as I know 93 to 97 Rodeos used a crush sleeve. Late model 07 to 2012 Jeeps use a crush sleeve as well. There may be other models with the crush sleeve as well. I guess it all depended on how many pennies the company purchasing the axles wanted to save.
 

·
Registered
Joined
·
13,615 Posts
Discussion Starter · #18 ·
Thank you !! I read that the 44's didn't get the big pinion till after 97, but the ring gear was a thick cut one...that was off of a link posted on here the other day... Very good info..!! The lack of a crush sleeve makes it nice to change yokes or seals...!! Most American made vehicles use crush sleeves un there axles, quicker ,better ,faster !! Even 14 bolts have a little crush sleeve if I remember correctly, can't remember about ford 9 in's... There fine and dandy till you have to work on them... I'm always worried the poor little pinion nuts gonna strip...
 
1 - 18 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top