The Stovebolt Site Forums The Shop Area The HiPo Shop Rrear axle conversion for a '42

I'm planning on changing out the rear end on my '42 at some point.
I noticed that 4 wheel drive GM trucks in the '80s use the same 6 lug pattern and I was wondering how much modification it would take to make the change.
If someone's done this, or can point me to something they have found to be a relativly painless conversion it would be appreciated.

i havent done it but those axles are probably way to wide to use under your 42 without narrowing.

If you don't mind the 5 lug... I used a 72 olds 442 w/ factory triangulated 4 link (GM G body). I'm in the process of putting it in my 46. The width is perfect. If you need to keep 6 lug I heard toyota shafts will fit with minor adjustment.

Yeah, I really want to keep it 6 lug. I'll look into it. Thanks.

I went the f*rd 9 inch route for my 1940 gmc. I was able to get a new rear end that was the right width... 61 inches wheel mount to wheel mount... 6 lug on 5 1/2 inch pattern, and choice of any gear ratio imaginable. The rear end was also set up for disc brakes. The 9 inch was a bit pricey if you add everything up, but I have all new bearings, new seals, shafts, pinion gear and posi. I also have the flexibility to change gearsets in the driveway If I am not completely satisfied with the 4.11 I have.

bigbadswingdaddy,(Man, If I reply to you very much I'll have to find an abbreviation!!)

Was the 9 in. you bought built to your specifications, or is something I could possibly find used?

Are you changing your rear end 'cause you want an open drive line? If your are, you might want to only change the pumpkin and keep your original housing and axles. A '55 half ton pumkin will bolt right in and you'll have an open drive line.

bbsd is fine for an abbreviation. I specked the rear end out. I started with an "IMCA Modified full floater rear end" on ebay, specked out the width, the bolt pattern, and axle splines. I got the center section in a seperate auction. It was a bit pricey, but I got everything I wanted... a bulletproof rear end with new bearings, axles, seals, gears, posi, and disc brakes. I didn't have to spend time or money looking for the rear end at the wrecking yards, and it was still cheaper than having a rear end shop around here go through a salvaged rear end. I also have piece of mind for parts availability if anything ever goes wrong, which it won't.

steppenwood ,I'm installing a 350/350TH tranny,(Mostly stock) so I'm just trying to find the right rear end. Without too much expense. I don't need any thing radical at this point. I could probably use the stock rear end, but it may have a problem.

bbsd, sounds like you have a nice set up. Mabey next year I can do something similar. For right now I just need something dependable for the engine swap as this will be my primary transportation. Next spring I'll buy a small motorcycle and do the truck right.

You said you "could probably use the stock rear end" (closed driveline) with your 350/350TH tranny? How's that going to work?

toyota 4 wheel drive is 6 on 5" pattern same as your chevrolet and they are narrow and sturdy. a lot of the "hoppers" use them. their bolt pattern is listed as 6 on 127mm =5". i bet the newer one's have disc brakes?

Steppenwood, I'm not sure about the "closed driveline" part.The driveline is closed from the rear of the tranny to the carrier bearing, about 1' from the rear of the tranny, there is an open driveline from that point to the rear end. This could be a newer rear end, but I don't think so. I'm almost positive it's the original. Is it possible that GMC and Chevrolet are different? Or even 1/2 and 3/4 ton? Mine's a 3/4 ton GMC. I'll take some pics tomorrow and provide a link.

10micron, that sounds like the perfect solution. I got the 235 running today and moved the truck (Not very far) but it seems like the rear end may be ok.
When I first bought the truck I was pushing it up to the garage and I could hear a popping sound and the driveshaft was "skipping" But while moving it under its own power it was fine. No popping.
I really felt like the rear end was ruined and figured that may have been the reason it was parked.
Your solution is exactly the kind of thing I was looking for.So if it turns out that my rear end is bad after I drive it on the road, I'll pick op one out of a Toyota at the junk yard.

Thanks much, Mike.

Steppenwood, Here are the pics. See what you think.
Also can someone identify the speedo?

http://community.webshots.com/user/mmcdaniel69

Thanks.

Mike, I have a '41 Chevy 3/4 Ton and it has the same driveline & rear axle arrangement, I'm pretty sure it's original. That arrangement is in the catalogs for 3/4 tons also. It has 6 lug wheels on a 5 1/2 inch circle.

3/4 ton and larger rear axles were open drive line.
Only 1/2 tons were torque tube all the way to the rear end.

Thats nice to know, I felt like it was original.

Thanks.

The speedometer is from a 1936 Chevrolet passenger car and was used in some 1936-39 Chevy trucks.

As for the rear end, I think that the pumpkin from a 1955-62 Chevrolet 1/2 ton with 3.90:1 ratio will bolt in?

wdot, Thanks for the information. I think the speedometer still works.
I'll probably have to use it to get my inspection sticker.
They start that here 1st of the year.
Poor people have poor ways!