1949 Chev 3600 rear axle inquiry

[chemelr]

On a series of Trucks on Spike TV, the guys are putting an updated axle on a 1949 Chevy 3100 truck. They say they are using a Ford 8.8 to replace the Chevy tubed differential. They suggested one from a 1995 Ford Explorer. It showed on their video I ordered that it fit right as far as width goes. They assembled it with a 4 link suspension.

OK - I have a 1949 Chevy 3600 pickup. I picked up an 8.8 inch, 3.73 limited slip differential from a 1995 Ford Explorer. The 3600 frame width at rear axle area is about 36" The Ford differential is about 64" from inside bracket plate to bracket plate. It looks way too wide when mocked up. On the TV show Trucks, their "Ford Explorer" differential was slightly wider than the frame - supposedly only a 1/2 inch difference from the original axle on the 3100. Secondly, their differential carrier was centered on the truck. With all the Ford axles I looked at, the carrier is off-center. That is a problem with the 3600 frame as the Paul Horton 4 link suspension I am going to use - part of it would have to be welded to the carrier and that ain't gonna happen.

Obviously one or both following statements has to be true. The 3100 frame is wider at the axle than the 3600 frame. Or the "1995 Ford Explorer" 8.8 inch differential was professionally shortened. Is 3100 wider than 3600? What have you guys used in the field for the 3600? Any and all suggestions will be appreciated as to the best differential fit for a 1949 Chevy 3600 pickup frame.

[Root2812]

http://chevy.oldcarmanualproject.com...51ctsm0202.htm

This link will take you to a page of the assembly manual that shows frame width. It states that the 1/2 ton (in the show) is 46" wide in the rear of the frame where as your 3600 is 36" so there is your 10" difference. Now if you have that axle under the truck it will stick farther out from the frame but what is the original width of your torque tube rear? Surely its out there farther or the same as the 1/2 tons. Measure your original rear and compare it to the explorer rear to see if you are close. The next problem is that the Paul Horton's kit has geometry built into it already and if your mounting points are 10" closer together you may run into issues there. Call and ask before you buy.

Lastly, recheck that rear end. If I remember correctly its should be closer to 60" not 64". You may have been sold and 8.8 out of somthing else.

Good luck and post up some pics and maybe someone here can help, or better yet maybe they have done the swap into a 3600 already.

[mechanixman]

I don't know about axle widths, I think they're the same. But you have to think about how the axle mounts to the frame.
A 3600 has a more narrow frame, because the springs mount on the side of the frame.
where as a 3100 has the springs mount under the frame.
I think the mounts are the exact same, so the rear end should fit regardless of the model, but It could reek havoc with that 4 link.
Have you considered a ladder bar system?

[solidaxel]

Lastly, recheck that rear end. If I remember correctly its should be closer to 60" not 64". You may have been sold and 8.8 out of something else.

That statement sounds correct!
The yard may have been more concerned about getting you a 3:73 and not the right width.
Ask again for the width of a Explorer rear end.

[chemelr]

Thank you everyone for the help. I suspected the frame width was the difference. It is back to the bone yard again with tape measure in hand.

Since I have already purchased a Paul Horton 4 link suspension and MII cross member kit, I think it would be easier to get a 3100 frame. Ironic that I got the 49 3600 from Montana where my family lives and there are several 3100's sitting around. I chose this one as it had a cab that is in excellent metal condition. Again thanks!

[cyclonewade]

Originally Posted by chemelr

Thank you everyone for the help. I suspected the frame width was the difference. It is back to the bone yard again with tape measure in hand.

Since I have already purchased a Paul Horton 4 link suspension and MII cross member kit, I think it would be easier to get a 3100 frame. Ironic that I got the 49 3600 from Montana where my family lives and there are several 3100's sitting around. I chose this one as it had a cab that is in excellent metal condition. Again thanks!

Send me a message I can help you use all your current components and the frame.

[solidaxel]

Was the sheet metal dipped or blasted?

[solidaxel]

Oooh, and by the way welcome from So. Arizona.
Lots of helpful folks on this site!

[chemelr]

The body was chemically dipped. I was generally pleased but I don't know if I would do that same method again. Dipping was about 95% effective. On the floor board where it was really rusty, it didn't do a good job. No big deal on that since the floorboard is going to replaced. I was at a car show in Puyallup, WA, where a guy advertised a new chemical method used along with electricity. He had an old pickup cab on displayed that was "pulled" out of a lake. The finished job looked so good. However it is expensive. This guy was out of Portland, OR. I wish I would have gone with that method. The traditional acid bath is way cheaper but you get what you pay for.

[chemelr]

I want to correct myself in that the 1995 Ford Explorer differential is about 54 inches wide from backing plate to backing plate. I put down 64" so it must be old age.

[Root2812]

Originally Posted by chemelr

I want to correct myself in that the 1995 Ford Explorer differential is about 54 inches wide from backing plate to backing plate. I put down 64" so it must be old age.

That sounds much better. That would be about 60 inches wheel surface to wheel surface then. I guess it comes down to you will either have to get a 3100 frame or trade the 4 link idea for something else (ladder bar, leafs, ect).

Good luck

[chemelr]

Originally Posted by Root2812

That sounds much better. That would be about 60 inches wheel surface to wheel surface then. I guess it comes down to you will either have to get a 3100 frame or trade the 4 link idea for something else (ladder bar, leafs, ect).

Good luck

I will probably return home to Montana as a friend of mine has 3 or 4 1949's sitting in his yard and I will get a 3100 frame. Montana is a great place to be looking for classics. Low humidity and not much rain makes vehicles last a long time. Thanks again.

[Root2812]

Originally Posted by chemelr

I will probably return home to Montana as a friend of mine has 3 or 4 1949's sitting in his yard and I will get a 3100 frame. Montana is a great place to be looking for classics. Low humidity and not much rain makes vehicles last a long time. Thanks again.

Thats the truth. My truck came from Montana and besides the typical floor rust its in great shape, well except for the running board. It looks like the truck was raked across every tree in sight.