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Will a 1962 GMC rearend work in my 1961 Chevrolet rearend? I know that with Chevrolets the rearend would work from 60 – 62. I have been searching for a rearend for my truck for a long time and finally found someone today with a collection of the old trucks in a mini-junk yard. However, the only 1960 ½-Ton Chevrolet he has he doesn’t want to sell, but he does however have several ½-ton GMCs from 1960 – ’62. So… would it work?

they should, i believe all the guts will interchange, but if you are talking about a complete axle swap, i don't think they will, chevy had trailing arms and springs, gmc had leaf springs like most newer trucks, you might beable to weld and convert the axle housing i'm not for sure

Look em over. It,s probably like Mike says. If they both have the removeable center section & round cover, the center section should fit. Some GMC,s used the Dana axle,s. They will have the intregal houseing with a uneven cover on the rear.

This allegedly '62 GMC has trailing arms and looks just like my '61 Chevrolet underneath. The '62 "GMC" has a Chevrolet cab on it, so I thought it was a Chevy at first, but the fellow insists that it's a GMC with a cab swap. Perhaps it is a Chevrolet, because like I said it looks the same underneath as mine, with the trailing arms and - not leaf springs.

It's probably possible to use my old rearend again, but I think it would be a pain. One of the axles broke while it was being towed (long before I got it) so it hit the road and caused some pretty dents on the brake drum should be. So I would prefer just getting the rearend that would hook right up. Someone gave me a rearend out of a '63 insisting it would work, but I told him, as I am sure most you know, that it wouldn't work because the trailing arms were moved in some inches - so the brackets where it bolts to the trailing arms don't match up...

Before 63, GMC & Chevy shared rear suspension styles, the leaf spring 2wd GMC came in 63. They should be the same rear axle assy. Brian

Ah! Thanks Brian, that must be it. I remembered after writing that I had taken a look at a 1960 GMC 1/2 Ton that he has and it had trailing arms also - it was sitting right beside a '60 Chevrolet that he isn't interested in selling and they looked about the same to my eye - so I guess they were!

Thanks for all the replies!! I'm looking forward to getting this rearend and getting it in my truck - not being able to find a rearend has been the only thing really holding me back.

I don't think that's right about the guts interchanging. Accoring to everything I've ever seen about the GMCs from that era, they used Spicer/Dana axles, rather than the Eaton manufactured axles used in Chevrolet. Now I do know that up to '62, the suspensions were the same, though, as 64fleetside points out. So a complete housing swap should work out ok.

Ok guys, sorry, but I’ve got a few more questions about the rearend deal.

Ok – so a 1962 GMC rearend should work, right? That's the one that I would like to go with because it is a sure thing right now, but...

I called someone today who actually has a couple of 1961 Chevrolet Apache 10s. He'll sell me the rearend, except first he wants to know all the details about the one out of my truck so he can be sure that it will work.

"I don't want to have to sell you the right one twice."

So my question is... is there anything that would be different from one 1961 Chevy rearend to another? If so, what? My truck is a SWB, manual transmission with a 235 motor. What exactly would work in it (and I mean just bolt right in!)? Would there be a difference in rearends if I got one from a '61 that had a different kind of motor in it?

Just saw this! Thanks. Yeah, that is what I would want to do anyway would be a complete housing swap.

Thanks, how would I find out what the gear ratios are for my truck?

Or would it just be that I would have to get a rearend from another truck with the same kind of motor and trans as mine?

Robbie,
You can't take anything for granted as many things may have been changed in these trucks since they were new. Try this method: Jack up one wheel, make a chalk mark on the driveshaft by the rear u-joint make another mark on the tire. Make 2 complete revolutions with the tire and count the number of revolutions the drive shaft made.
3 1/2 turns = approx 3:55 ratio, almost 4 probably 3:90's, a little over 4, probably 4:11's.
It's not exact but close. Of course it would be a good idea to look at the condition of the gears in the one you are getting, then you could count the teeth and be sure.
Fred

I can do that on the one that I would be getting, but I wouldn't be able to on the one out of my truck as it has already been gutted (not by me!). I just have the casing.

Ok - so how would I know which one of those would be appropriate for my truck. As I have said before, it has a 235 and 3 speed trans.

What kind of difference would it make putting in a rearend with a different gear ratio than the original?

And thanks for all the replies. I'm very thankful I found this site!!!

Robbie,
The standard gear ratio for the 1/2 ton Task Force trucks (55-59) was a 3:90 ratio, unless it came with overdrive in which case it would have a 4:11.
I am fairly sure that the early 60's trucks followed that same pattern. I guess it depends on how much running you plan to do at freeway speeds what ratio you would be happy with. There were other higher ratios available which would make for better cruising speeds. A 235 is wound up fairly tight at 60 with a 3:90 gear. I put overdrives in everything so I don't have any issues with ratios.
Fred

Robbie,

Here are 1961 Chevrolet factory Rear Axle codes and ratios:

I believe the 3.55 ended in 1960 and replaced by the 3.38 in 1961.


Series Code Ratio Plant
Corvair 95 BL 3.89:1 Detroit Gear & Axle
Corvair 95 BY 3.89:1 Detroit Gear & Axle

1/2-Ton MA 3.90:1 Detroit Gear & Axle
1/2-Ton MB 3.38:1 Detroit Gear & Axle
1/2-Ton MC 3.90:1 Detroit Gear & Axle
1/2-Ton MD 3.90:1 Detroit Gear & Axle
1/2-Ton ME 3.38:1 Detroit Gear & Axle
1/2-Ton MF 3.90:1 Detroit Gear & Axle
1/2-Ton MG 3.90:1 Detroit Gear & Axle

3/4-Ton MH 4.57:1 Detroit Gear & Axle
3/4-Ton MJ 4.57:1 Detroit Gear & Axle
3/4-Ton MK 4.57:1 Detroit Gear & Axle
1-Ton PA 5.14:1 Detroit Gear & Axle
1-Ton PB 5.14:1 Detroit Gear & Axle

Just thought I'd add some info.
Brian