The Stovebolt Site Forums The Shop Area Driveline AD differential swap?

Hi All
Is there an open drive differential swap for a 47-53 1/2 ton AD? That is, is there any open-drive pumpkin that will bolt into the existing rear end using stock axles?
thanks

Hy wurlitzer46, the 1/2 ton 1955 B or second series differential will swap into the torque tube housing. I believe the same differential was used up to 1962. Once you make your swap you will have to do something about keeping your new pinion in position as your torque tube housing will pivot on the rear springs allowing the pinion to fall down. You could have someone weld leaf spring mounts to your housing and you will have to obtain some "U" bolts and plates to bolt the housing to the springs. Don't forget the pinion angle needs to be set before the welding, hope that helps.

Thanks, do you happen to know what gear ratio those trucks usually have?
And can you just weld the old pivots to not pivot?
This would seem the simplest solution, but not many do it, so maybe there is a reason?
the usual choices are either a complete rear end swap or the Patricks pinion and ring in the stock torque tube (does anyone still sell those?)

The pivots have a rubber bushing in them, so welding would probably destroy that. And the pivot housing is cast, so may not weld that easily. If you can get an entire rear axle housing from a 55 second series, that would bolt to the springs and use the same wheels.

I believe Mother Trucker still has the 3.55 ring and pinion set for the AD's.

The rear ratio is 411 on the pickups with 390 for 1954 pickups and newer,I see in your signature you have a ice cream truck there is one on Facebook you should check out .

Thanks, gents. 390 ratio might not be enough improvement to be worth swapping in a 55-62 pumpkin, unless there are some out there with a higher ratio? Or, since it would need spring mounts anyway is there a good 6 lug rear end the right width that would have a higher gear?

I could find a 54 torque tube cheap, but that means a torque tube, and still only a 390 ratio

Where is Mother Trucker, or someone who sells the ring and pinion kits nowadays?

Contact Mother.Trucker on here by PM. He's around on occasion.

This MotherTrucker is not the member you want to contact about parts

I think that this MT (Mother.Trucker) in AZ is who you want to contact?

Yep, with the period in the username.

I first joined this group with Wally / MT as my user name. I had to switch it to my current one because of the confusion with Mother Trucker himself.

Wurlitzer,
You mentioned you're looking for a higher gear, but haven't said what transmission you'll run.

I did this swap in my 50 half ton: 4.11 torque tube and 3spd out, 3.90 Task Force truck open drive center section in, solid spring perches, and a T5 transmission behind my 216. It's a good combination.

are you able to drive highways with a 3.90?
I was figuring on a 235 with the Muncie sm420.

So that is direct in high, that is what counts!

Ed