The Stovebolt Site Forums The Parking Lot Tons 'o Fun 1 ton rear ends

Can I narrow the scope of your question? Looking just at the years with Eaton rears?

The Eaton rear was under all '47 and later 1-ton GM trucks up into the 60's, but by the end of the 60's Dana rears were used under at least some 3/4-ton trucks and may also have appeared under some 1-tons. Sometime in the 70's the GM 14-bolt replaced the Eaton, and though they have some similarities, they are a different rear. And at some point many 1-ton trucks came with the Dana 70HD including my own '89 K3500.

So I'm going to assume your question was just about GM trucks with the Eaton rear.

The spring pads welded on a '61 1-ton Eaton are wider and possibly positioned differently than on a '55 1st 1-ton Eaton. I've seen this difference with my own eyes and based upon it would imagine that the spring pads may be a little different in each series of trucks.

Another area of difference is the brakes. Early rears have Huck brakes and later ones have Bendix. I've heard enough about the problems in switching that I'd suggest getting a rear with the brakes you want. Aparently both the housing and the axle shafts are different between these two types of brakes.

I doubt this is an exhaustive list of all the differences, but just the items I could list mean the quick answer is no, they are not all the same.

If you can be more specific it may be that I'm listing differences that don't matter to you.

Bruce I just don't know the answer with certainty. I think the answer is that they are the same, but I can't prove it.

The information listed in the Restoration Pack does not show any differences in either the rear axle or the brakes on the rear, and even shows the same wheel bearings front and rear on all 1-tons. The front wheel bearings are the same on 3/4-ton to 1.5-ton trucks according to the resto pack.

Restoration Pack

Bruce,

Have you measured the wheel mounting surfaces face to face?

Usually, the dually rears are slightly wider in order to get the inside tire away from the spring because of the wheel offset. Spacing of the spring mounts 'should' be the same depending upon frame width (usually around 34 inches for a one ton).

Lane

Lane,the spring mounts on AD and TF ton rears are the same,the AD had a 36 inch frame and TF had a 34 inch frame.The difference was in the spring hangers.I'm using a 55 TF 3/4 rear under my 50,better gear and brakes are a lot easier to find.Also my 16 inch duals fit over the drums.

I think if you go to the online parts manual on "Old Chevy Manuals" you will find that the drums are different part numbers between the single and the dual. At least that is the case for 1951.