GM G80 locker axle transplant on Sprinter along with 4x4 conversion

luthj

Engineer In Residence
Once you break 9 ft, whats another 3 or 4 inches eh? Or at least thats how the logic goes.
 
So back on topic:

Looks like I am heading back to doing the deed with the 9.5"

What I found looking for 10.5s: for the sure thing full meal deal with sensors, means 2009-2010 model year. These are going on average for $1000-1500 on the used market with one available locally at $895. This is flat out a no go for me based on price.

To add tone rings AKA the artec kit, to 10.5" years 99-2006, bearing axle hubs need to be machined and tone rings press fit. This means pretty close to the same machine shop charges for turning tube ends square in my design for 9.5" modeled above in this thread, I would prefer to laser cut 44 tooth rings anyway rather than use arduino for correction from 52 or 60 tooth rings, and adding sensors is exactly the same proposition regardless of 10.5 vs 9.5. So costs and amount of work in either case is a wash.

And, trying fo find a 10.5 axle at a good price to restart the whole dang process, then having essentially the same amount of work to do on it as this 9.5 that I already have... well...

Two things remain questions regarding the ring and pinion in this 9.5" :

I checked a couple of the diff ring/pinion aspects on my 9.5". Backlash is in spec at .008. I am looking for input as far as gear contact pattern. Looks pretty good to me. Concern... close to the top land on coast side, but land looks like good thickness.

contact-1.JPG

contact-2.JPG

I measured pinion preload it is way under spec, 1 in-lb. almost free spinning

spec is:
Pinion Preload New: 15 to 22 in-lbs
Pinion Preload Reused: 7 to 9 in-lbs

Whaddya think, Just re-crank preload?
 
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luthj

Engineer In Residence
Low preload indicates worn bearings, though it doesn't take much wear to drop the preload down significantly. If this unit has a crush sleeve, they can relax a bit over the years. With a crush sleeve, tightening the pinion nut can work to increase preload. It will be very sensitive, like 5 degrees sensitive. Assuming the bearings aren't damaged, tightening the nut won't change the pinion depth/mesh.

If the pinion bearings are nice and smooth, even after you add some preload, I wouldn't be concerned. Even if they start to go, you will get plenty of warning before they bite the dust.
 
Low preload indicates worn bearings, though it doesn't take much wear to drop the preload down significantly. If this unit has a crush sleeve, they can relax a bit over the years. With a crush sleeve, tightening the pinion nut can work to increase preload. It will be very sensitive, like 5 degrees sensitive. Assuming the bearings aren't damaged, tightening the nut won't change the pinion depth/mesh.

If the pinion bearings are nice and smooth, even after you add some preload, I wouldn't be concerned. Even if they start to go, you will get plenty of warning before they bite the dust.

That's what I figured. pinion bearings feel fine, I'll give it a whirl.
 
Cranked preload, got it to 8-10 in-lb. As it is reused I am going to leave it there.

I think I am set with the innards. Now to the tone ring assembly. I got one quote on the DOM tubing at ~$30 long enough to check in a lathe and my local machinist says around $40 to square, part and finish 2 pcs. All I will need are the laser cut disks, then mount sensors. Then do the welding bits to get it to play with the Sprinter mounting.

This is a go!
 

luthj

Engineer In Residence
Cool, sounds like you got a plan going forward. I will be interested in how it performs. If/when my MB factory axle goes, I may want to head that route.

Get me the final measurements and I will add a tone ring to your DXF cut package.
 
WOW! Many things in my life have been going quite poorly lately. Today I am a happy man. I finished the setup on this diff:

Spec:
Pinion Preload New: 15 to 22 in-lbs
Pinion Preload Reused: 7 to 9 in-lbs

My final preload 10-12in lbs

Spec:
Ring Gear Backlash: .006" to .010"


My final backlash .007"

Contact pattern PERFECT!

drivecontact.JPG


coastcontact.JPG
 
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Figured I'd follow up. it's been a while. I came down with a bad case of Leukemia last October. I am not out of the woods, still having blood transfusions for anemia and getting over fungal pneumonia (both due to the cancer) but regained a little bit of energy. The Sprinter has been up on blocks since last September. I only hope I can get it back on the ground and mobile soon!

So, yesterday, finally I got back to this project.

I had the flat parts laser cut when I had the frame assembly cut for the 4WD project. The center is 3.5" ID DOM pipe I had my local guy lathe square.

Here is the spacer which provides level surface for tone ring assembly to sit on.

spacer-1.jpg


And in place on the wheel flange

spacer-2.jpg


Here is a tone ring assembly freshly welded and set in place on the spacer. Now I need to drill and tap holes, clean everything, paint and bolt together.

tone ring-1.jpg



Note: Sprinter tone rings are 54 teeth. GM are 55 teeth. Close enough, no electronic frequency adjustment required.
 
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MTVR

Well-known member
As far as your project goes, you sound like a smart guy, and you've gotten some good input from Len.Baron too.

The 9.5 is,as has already been pointed out, kind of an "orphan" axle, but it does meet your needs.

Like Len.Baron, I am not a big fan of the gov-lock. I'd trade your G80 axle for an open one, and use a drop-in ratcheting differential like Len said.

Either way, I wish you well... :)
 

luthj

Engineer In Residence
Obviously not applicable to the OP, but if anyone else is going to attempt this particular mod, certain years of GM 2500 vans with active brake control have a 9.5 rear axle with 55 tooth tone wheels and inductive pick ups. Need to be careful though as some of them are dana super 70? which have no aftermarket differential options.

The Dana in those vans is truly an orphan axle though. The 9.5 at least has diff options and aftermarket shafts.
 
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