Rear Locker for Express

[TheLetterJ]

It's pretty straight forward, you'll need to pull the shafts to measure the length from inside of flange to end of spline (don't forget to compensate for which side will need to be shorter and which longer due to your proposed change in cross pin location!) count your splines, and measure the bolt circle of the flange. I know you have those last 2, but it won't hurt to verify.

I have seen shafts sold as "cut to length" that have 4-6" of spline that could work if you're uncertain of the direction of shift in cross pin location, but pulling your diff cover to measure is easier to do than cutting shafts later.

Then, just go here https://dutchmanaxles.com/index.php fill out their "custom flanged floater" order form, fire off an email and wait a month(ish.) I know that 4.51" flange is abnormally large, so ordering may require a phone call. If that turns out to be a problem, there's still other methods (double splined shafts instead of flanged) and other manufacturers to try.

Edit: I misread and thought 4.51" was your bolt circle, but since it's actually the o.d. of the flange, you should be good to go.

[BroncoHauler]

The downside of a custom axle shaft, is if you are ever on the road and need a replacement. That will have you sitting for a while until a new one is built and shipped to you.


Are there possible axle swaps (the whole enchilada) to a more standard setup that might be better? A bigger pill to swallow up front, but might make your life easier down the road.




Herb

[TheLetterJ]

While that is true, a 35 spline 4130 full float shaft is hardly what I'd consider failure prone.

That said, a 14 bolt from another van would get the job done, probably already has 4.10's, and a Detroit locker is a cheap(er) bolt in affair with no knowledge of gear setup necessary. I don't know what years are a direct interchange, but they were definitely used on your era of express... I drive passed one almost every day.

[gahamby]

I was told by a vendor that no locker was available for the 12 bolt open rear. I've been researching this on and off for a while now. The signs point to getting a 14 bolt compatible rear axle, installing a locker, and replacing the whole rear axle.

[jumph4x]

Originally Posted by TheLetterJ

While that is true, a 35 spline 4130 full float shaft is hardly what I'd consider failure prone.

That said, a 14 bolt from another van would get the job done, probably already has 4.10's, and a Detroit locker is a cheap(er) bolt in affair with no knowledge of gear setup necessary. I don't know what years are a direct interchange, but they were definitely used on your era of express... I drive passed one almost every day.

Originally Posted by gahamby

I was told by a vendor that no locker was available for the 12 bolt open rear. I've been researching this on and off for a while now. The signs point to getting a 14 bolt compatible rear axle, installing a locker, and replacing the whole rear axle.

I meant to post back in here, this was my conclusion as well. If I'm not mistaken, this will be a very straightforward job:
- drop shocks
- disconnect brake lines (drain)
- disconnect sensors
- disconnect driveshaft
- disconnect u-bolts

Am I missing anything? I doubt the ABS/Stabilitrak tone rings are any different. Worst case I will have to have a section of the driveshaft fabricated. Do these factory ECUs care what the final drive is like Mercedes do? Or does the computer only reconcile the wheelspeed against the front axle with a margin on top for turning radius and off-track?

What is a good resource to get me started on identifying exactly in which vans the axle came in?

[jumph4x]

Just for general education and awareness: are the modern Ford E line much better about this compared to GM?

I should do some pro/con research now so I know which platform I'm choosing next. Sounds like 4x4 Sprinters are also a PITA when it comes to lockers.

[TheLetterJ]

A complete rear axle swap is about as easy as you made it sound IF it came from the same era van. I'd be willing to bet that your driveshaft flange would bolt up too, but I can't speak for the electronic side of things.

The Ford vans can be easier to deal with as far as parts availability, but that certainly doesn't make them better. Your dana 70 is probably stronger than anything that came under a SRW e-series. Most e-series came with a semi-float (c-clip) dana 60 which really is not up to the task in such a heavy vehicle. Many (mostly e350's) came with full float dana 60's, but they had an e-series specific spline count of 32, so the options for diffs are slim (ARB) but a swap to 35 spline shafts (what I did) opens up lots of possibilities.

Both platforms have their pro's and con's, so I wouldn't even consider switching to the other platform unless there was a specific drivetrain that you desired.

[jumph4x]

Originally Posted by TheLetterJ

A complete rear axle swap is about as easy as you made it sound IF it came from the same era van. I'd be willing to bet that your driveshaft flange would bolt up too, but I can't speak for the electronic side of things.

The Ford vans can be easier to deal with as far as parts availability, but that certainly doesn't make them better. Your dana 70 is probably stronger than anything that came under a SRW e-series. Most e-series came with a semi-float (c-clip) dana 60 which really is not up to the task in such a heavy vehicle. Many (mostly e350's) came with full float dana 60's, but they had an e-series specific spline count of 32, so the options for diffs are slim (ARB) but a swap to 35 spline shafts (what I did) opens up lots of possibilities.

Both platforms have their pro's and con's, so I wouldn't even consider switching to the other platform unless there was a specific drivetrain that you desired.

Got it. Well, thanks for that.

As things stand, this is going to go dormant for a while. I cannot afford the time and energy investment of this for at least 6 or so months. But I will revisit this. If and when I make more progress, I'll post back. The added benefit of this is junkyards receiving more of these vans. I currently only see a handful with 50 miles from me.

Thanks all, for direct and quick feedback loop.

[newoldguy]

Haven't read all the posts.


I have a 2002 Express with a 5.0L. I have a two inch Weldtec front end leveling lift kit.


I mainly use this van for towing a 22 foot travel trailer so didn't mess with a larger diameter tire but I did have a shop install a Positraction unit in my 10 bolt rear end. We do some light off road stuff after we set up the trailer. It has really helped on loose dirt roads.


IMO, lockers are for real serious stuff and 2wd could be a problem for a vehicle that heavy. Good luck.