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

luthj

Engineer In Residence
I think it was 2011? that GM switched bolt patterns on the 2500s, From 2005/7 range they started using abs sensors on the rear wheels. I am not 100% certain though.
 

Len.Barron

Observer
a 2009/2010 silverado/seirra (6.0 gas) 2500hd with active brake control would be a great donor(10.5) , find one with GT5(4.10 gears) and without G80 (and just install the $400 detroit locker instead).
 
Well I went and checked the door tag on truck I pulled that 9.5 from axle rating is 6000, which is plenty.

I also had a look at 11.5 and 10.5s, but all were pre 2001. The 11.5 is WAY too much! 10.5 pretty reasonable, but in terms of load and duty the 9.5 would be just fine.

Lockers/posis currently available for the 9.5:
ARB air locker
Detroit locker
Powertrax lunchbox
Detroit true trac
Yukon Dura grip clutch style posi

I'll make a couple calls tomorrow, but this 9.5 is back in contention for my attention.
 

locrwln

Expedition Leader
Nothing wrong with 9.5's. GM started using them in 3/4t trucks beginning in 1981. There are thousands upon thousands of those axles that were used hard day after day. If you can find one out of an H2, it can have an electric locker (Eaton E-Locker) already installed with disc brakes and ABS sensors. Other than the tone rings you are dealing with, they are a very decent axle.

Jack
 

Len.Barron

Observer
10.5 would be the perfect fit for you, GT4 RPO code is 3.73, I'm not bad mouthing the 9.5, if you don't ever want to do anything to it then it's fine, but, from a builders perspective it boxes you in. I agree the 11.5 is too much...you really need to be at 34" tire mininum to consider it, otherwise you'll be dragging it over everything..
 
Last edited:
10.5 would be the perfect fit for you, GT4 RPO code is 3.73, I'm not bad mouthing the 9.5, if you don't ever want to do anything to it then it's fine, but, from a builders perspective it boxes you in. I agree the 11.5 is too much...you really need to be at 34" tire mininum to consider it, otherwise you'll be dragging it over everything..

I tend to agree about 10.5 probably being more HD and a potential sweet spot, but price does matter, and right now there's nothing available in reasonable shape for less than $550 with a G80. And there's no telling whether I'd have to reset pinion and backlash on them as well until I see them. The 10.5 pinion is desirable in that sense, relying on shims rather than crush sleeve for preload.

Anyway, I am pretty well set on G80 being my starting point for a locker, I am just not looking for severe conditions driving this van. But if that unicorn shows up...

Otherwise, I don't feel bad at all working on this 9.5". I'm retired, I have lots on my plate, but in the grand scheme I actually have the time to do this kind of extra work.
 

Stevemo

Member
The one thing I don't like about my 2004 Chevy 3500 with the 3.73 gears is that it is a real struggle to back up over anything. The 6.0 is way too fast going forward (like dangerously fast) but it sounds like you are doing a brake stand if you need to back over a pebble. Hopefully your Sprinter transmission has more sensible reverse gearing than what I've got. The 4.10s gives an extra 2000 lb towing capacity on my model van.
 
The one thing I don't like about my 2004 Chevy 3500 with the 3.73 gears is that it is a real struggle to back up over anything. The 6.0 is way too fast going forward (like dangerously fast) but it sounds like you are doing a brake stand if you need to back over a pebble. Hopefully your Sprinter transmission has more sensible reverse gearing than what I've got. The 4.10s gives an extra 2000 lb towing capacity on my model van.

I have never had trouble with the 3.73 in the sprinter in forward or reverse.
 

luthj

Engineer In Residence
The NAG1 reverse is about 3.2. Backing up steep hills I have found the ratio to be too low numerically. So the boost comes on, and the wheels start to slip. Less of an issue with low range though.
 

Len.Barron

Observer
my thoughts on moving to 4.10 were based on most folks doing a 4x4 conversion/axle swap are also going to run a bigger tire, in those cases you'd just be restoring the ratio back closer to stock..
 

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