Rear Locker for Express

[jumph4x]

The sentiment is pretty consistent then, G80 is not an option. So, all things considered, is there a sane way forward or do I just give up and rock the traction boards?

Let's say I'm open to investing more money and do a partial conversion. Has this been done, has anyone documented it? I assume SMB just leave the rear axle open, or begin with a van that has supported rear ends to begin with.

EDIT: Some information here, but as always, nothing conclusive and no solutions https://www.cheaprvliving.com/forums...=25715&page=10

EDIT2: Hey look, another dead end thread http://www.sportsmobileforum.com/for...cker-9894.html

[TheLetterJ]

Are you planning to install the differential yourself? Or, are you mechanically inclined enough to do a little exploratory disassembly?

Everything I'm finding points to that being a Dana Super 70, which is still 35 spline, and still uses standard Dana 70 gearsets. The housing itself is the biggest difference with larger tubes that do not taper near the ends, increased webbing on the pumpkin, and 12 cover bolts instead of 10. If it is indeed a super 70, it should have screw type bearing adjusters instead of shims too, which will be easy to identify, and much easier to work on.

You can pull a shaft without making a mess too, just jack up one of your rear wheels as high as you reasonably can and pull the high side shaft out. If it's 35 spline and 1 1/2" in diameter at the splines (same as standard dana 70 and 35 spline 60's), you're headed in the right direction and will not need new shafts.

Next step is to pull the cover and verify part numbers on the carrier. If it crosses over with a standard dana 70, that will open up a lot of options including ARB, Detroit, or even a Dana trac loc (not to be confused with a govloc.)

Also, do you plan to regear at the same time?

[jumph4x]

Originally Posted by TheLetterJ

Are you planning to install the differential yourself? Or, are you mechanically inclined enough to do a little exploratory disassembly?

Everything I'm finding points to that being a Dana Super 70, which is still 35 spline, and still uses standard Dana 70 gearsets. The housing itself is the biggest difference with larger tubes that do not taper near the ends, increased webbing on the pumpkin, and 12 cover bolts instead of 10. If it is indeed a super 70, it should have screw type bearing adjusters instead of shims too, which will be easy to identify, and much easier to work on.

You can pull a shaft without making a mess too, just jack up one of your rear wheels as high as you reasonably can and pull the high side shaft out. If it's 35 spline and 1 1/2" in diameter at the splines (same as standard dana 70 and 35 spline 60's), you're headed in the right direction and will not need new shafts.

Next step is to pull the cover and verify part numbers on the carrier. If it crosses over with a standard dana 70, that will open up a lot of options including ARB, Detroit, or even a Dana trac loc (not to be confused with a govloc.)

Also, do you plan to regear at the same time?

I'm pretty mechanically included, can do some of that.

My main hesitation is this feedback:

...oddball cross pin offset and staggered axle shafts. This prevents ANY aftermarket carrier from fitting with out also changing axle shafts etc.

This is the deviation from a true Dana 70, this is what makes it listed as Dana 70GM in some catalogs. Makes it sounds like I will need custom axles made at the least.

As far as gearing, I don't mind the 3.73. I do a lot of long distance highway driving and this suits my needs very well. Even with 33s.

I like your idea of opening it all up and documenting what I find. Here is what I have on my list:
- photograph axle
- count axle splines
- measure length
- measure all diameters
- photograph axle housing
- photograph carrier
- measure ring gear
- write down all markings and stampings

This will have to wait, it is currently driftcar build season Looks like I have another snowboarding season with open 2WD to look forward to.

[marret]

I don't have anything to contribute at this point, but will follow along as an interested party.

Thanks for posting and wish you success.

[jumph4x]

Brian "Gus" from Yukon\Randy's had this to say about identifying the axle:

We would want to start with the BOM# so we can accurately identify what variations etc it has.

Attaching his instructions image. I got under the van and started sanding.

Bottom left of carrier housing:
Top cast: 273?
Bottom cast: 3318 or 5318?

Bottom right of carrier housing:

Cast: 51999

Also I'm going to type out the Dana factory label for the sake of indexing this in Google.

Dana P\N: 2001079 1
09-DEC-2005
Serial No: 65FX8 M53430411
Broadcast: FX8
Ratio: 3.73
Plant: CBA
Diff: STD
Model: 70S

[jumph4x]

The BOM explosion from Dana themselves on this:

Bill of Material: 2001079-1
Diff. Type: STD
Ratio: 3.79
Ring and Pinion Kit: 84431-5
Differential Assy Kit: 84692
Differential Case Kit: 52589
Diff Inner Parts Kit: 708181
Right Hand Shaft Assembly: 52033-3
Left Hand Shaft Assembly: 52033-4

[TheLetterJ]

52589 looks to be a standard 35 spline dana 70 carrier, no funny offset cross pin or spline counts about it, but I'm not ready to put money on that answer just yet.

If that turns out to be the case, that would mean that ARB RD173, Eaton e-locker EAT14032-010, Powertrax/lock rite PTX2710-LR, and at least a few others *should* fit. An email to any of the diff manufacturers should be able to verify.

[jumph4x]

Originally Posted by TheLetterJ

52589 looks to be a standard 35 spline dana 70 carrier, no funny offset cross pin or spline counts about it, but I'm not ready to put money on that answer just yet.

If that turns out to be the case, that would mean that ARB RD173, Eaton e-locker EAT14032-010, Powertrax/lock rite PTX2710-LR, and at least a few others *should* fit. An email to any of the diff manufacturers should be able to verify.

That would be swell. Waiting on Gus to confirm this.

Already tried sending an email to Eaton twice, no response both times a year apart.

[carringb]

Have you tried calling or emailing Randy's Ring and Pinion yet? They seem pretty good and finding all options for weird Dana combos.

The E-series Dana axles tend to be not-quite-standard as well. My van originally had a Dana 70 housing but the Dana 60 carrier/ring/pinion. Later, I upgraded to full Dana 70 internals, but the 32-spline shafts required some mixing and matching of parts carrier parts to get limited slip. Now I have a Dana 80 housing, with a Dana Super-70 10.75" carrier and 37 spline shafts from an E450. That left me with the Ford Trac-Loc clutch based limited slip for the only option.

[jumph4x]

Originally Posted by carringb

Have you tried calling or emailing Randy's Ring and Pinion yet? They seem pretty good and finding all options for weird Dana combos.

The E-series Dana axles tend to be not-quite-standard as well. My van originally had a Dana 70 housing but the Dana 60 carrier/ring/pinion. Later, I upgraded to full Dana 70 internals, but the 32-spline shafts required some mixing and matching of parts carrier parts to get limited slip. Now I have a Dana 80 housing, with a Dana Super-70 10.75" carrier and 37 spline shafts from an E450. That left me with the Ford Trac-Loc clutch based limited slip for the only option.

Yeah, I'm talking with Brian Gus, like I mentioned in the thread. This is what he had to say:

Sorry for the delay, I was in meetings most of the day in preparation for SEMA



I re checked your carrier, it does indead have a ½” offset cross pin compared to all other dana 70’s, requiring diferent axles.

Your axles do not use the common dana 4.75”flange with a 3.96” bolt pattern, but instead use the GM 4.51” flange with a 3.56” bolt pattern



I dug thru the books to try to see if I could come up with a variation of shafts with the correct lengths and flange, but GM did there homework trying to ensure they were proprietary. It looks like to do the swap, you will need to find a company that will do custom 35 spline, gm pattern flanged axles. ( expensive ) there are lots of options for any other manufacturer.. just not the GM variations.

TheLetterJ,

Tell us more about the process of ordering custom machined axles.