The Stovebolt Site Forums The Shop Area Engine Shop Rear End from 1963 3/4 ton --> 48 3/4 ton?

Hello,
I have a 1948 3600 3/4 ton, and like most of this age/size truck has a pretty short gear ratio rear. I have to opportunity to pick up a 1963 3/4 ton rear end for about $40. It has 3.90 or a 4.57 gears (not sure). Is it worth the hassle, or should I look for something else?
Could I use the whole axle, part and parcel, or would I end up just robbing the pumkin, and leaving the rest of the hulk on the scrap heap? Are they the same width?
Thanks
Aaron

I actually ran into the same situation on my 52 3600 and found that 3.90:1 is about the tallest [highest]gear ratio you can get for that carrier assembly. We just swapped out the R&P gear and a bearing and it worked fine. I can't swear to it, I am sure someone else here at Stovebolt can verify but I beleive the 3/4 ton carrier assembly is the same up until 1972. Any gear ratio taller that 4.47 or 4.11 will help especially if you do any interstate driving.
JimBo

Anything 3/4 or 1 Ton from 1946 through 1972 are "Carrier Swappable".

In order to use the aftermarket ring and pinion sets that were available until recently, you needed a 67-72 carrier, as they are slightly different -- and several were available for the manufacturers to test with. Just swapping in a newer carrier with stock gears should be fine.

If I'm wrong someone will come along an correct me.

Thanks for the info. How much do you think this thing will weigh? It is complete with brake setup.

I don't know how much it weighs. I would guess that it's pretty heavy, though.

I've never done a whole axle.

All you really need is the carrier.

It's an all or nothing deal... I'm wondering if it is worth the hassle, since I won't be able to deal with it, once I have it, for a while.

If it is the 3.90 gears grab it, they aren't real easy to find, and are popular for this swap.

If storing it is a problem remove the center section and keep that part and dispose of the rest.

$40 is real cheap for 3.90 gears. If its the 4.57 I'm not sure it would be worth the hassle. What gears do you have now?

You're going to end up with one full rear to dispose of whether you swap the pumkin or complete year, so if your brakes, bearings and seals are good I would swap pumkin only.

If its 3.90s, you need to get it, no matter how much hassle is involved. I think it is probably a 4.57 if its from 63. I am not sure if you have a mudbog near you, but the guys that run here are buying up the 4.56 and 5.14 eatons to put in their trucks as they are slightly narrower, bulletproof and much cheaper than a 14 bolt FF or Dana 60 (or 70). Unfortunately they guys with jeeps have also realized a 67-72 Eatons with a 4.10 fit real nice in their "trucks", too and many have detroit lockers in them from the factory.

that sounds like a good deal. grab all the Ebrake cables too.
measure the rear of your truck. On my 3100 i used a 77 burb 4x4 1/2t and that was a great swap.
later on if you want to you can change ring and pinion but i don't think you will need to
look into a T5 or other tranny

I think I am going to pass on it, since I can't really afford the time to do swap anytime soon. I would really like to do it, but I just can't justify finding a place to put it for now. The rear in my 48 is a 5.11 or maybe a little higher, and needs the seals ans such gone through too.

Just wait I'll be in here asking if I should get the same rear end next year for $200. :mad:

FYI, since it looks like you are in the area, if you are interested you can pick it fo yourself. Link to AD

Thank for all of the help.
Aaron