1963 GMC what rear end?

[neto]

It's a 1963 GMC suburban with the 305. What rear end do I have? What gear ratio? One wheel turn equaled about 3 1/2 drive line turns. I have to replace the right rear bearing and all the brakes.
Thanks.

[64fleetside]

its a dana axle, prolly 3.54 ratio IIRC

[neto]

Thank you. I found the tag under some caked on dirt. It is a 3.54. Bearing is shot.

[Captainfab]

Is your truck a 3/4 ton? Typically the 1/2 ton GMC's had Dana 44's and the 3/4 tons had Dana 60's. By looking at this pic at the area circled, it is a Dana 60......and yes the Dana axles were available with 3.54 gears.

[neto]

It's a half ton. Suburban but not sure if maybe the rear end was changed. The other question I have is the little light turn signals on the hood. They look original but don't know if they are. Have to do more research.

[neto]

These is the bearing and a ring that's goes after the bearing. Do these axles have this grove like area? The bearing wasn't bad it was just riding on the grove area.
Thanks.

[Captainfab]

I'm assuming that the axle bearings are supposed to be pressed on the axle?
I would say that axle is junk.

[neto]

Yup it is. My brother came over and saw it and said the same thing. Now I'm in the process of finding one.

[neto]

I'm having a heck of a time finding any information on axle replacement and bearings (88128 yyn). It's a 35 spline. Am I missing something here?

[neto]

This is really getting interesting. This may actually be a NAPCO rear end. That's why the BOM number was changed.

[Captainfab]

No, it is definitely a Dana rear end. After having seen the pic with the '60' on the casting, I'm thinking you may have one of the rare Dana 60's with the 6 lug axles. I didn't know they existed until I read about it here on the forum several months ago.

I'm thinking you may need to get a set of custom axles to replace that one bad one.

You might try sending a PM to 71Bowties. He has a 6 lug Dana 60, and he might be able to help you find what you need.

Originally Posted by neto

This is really getting interesting. This may actually be a NAPCO rear end. That's why the BOM number was changed.

[neto]

Thank very much. Will pm him.

[neto]

So dumb, I miss counted the splines. It's 30 count. I got the bearings from napa, so the quest continues.

[justcuz]

I would guess it was for a heavy GVW package on the Suburban. The BOM may have been changed for GMC parts matchup since the rear axle is not common.
GM stopped using Napco conversions in 1960, unless it was a 3/4 ton suburban (8 Lug) or panel or 1 ton pickup.
If it was a Napco it would have had HO52 or HO72 front and rear axle housings with the dropout center sections like a 9 inch Ford. Someone posted up a picture of a 1 ton GMC panel truck that was a Napco showing the axles.
What you have is actually more unique than a Napco, not many Dana 60 semi-float rear axles were used in early GM products, especially a Suburban.
The most common modern use of the semi-float Dana 60 today is in light duty F-250's from the 80's.

[neto]

I can't even find the right brake bar for the e brake. "unique=PITA" lol. But I will take the challenge. Having the second drum coming the first one was not deep enough at the axle. The bar is a bendix 303397 but can't find it. I wonder if I can make one? Has anyone make one before?

[justcuz]

See if that bar cross references to an 80's Ford F-250 with the semi-float Dana 60 rear axle. You might get lucky and find that the backing plates and brakes could be the same. Ford used the semi-float Dana 60 from 1980 untill they started using the Sterling rear axle (around 85-86).
In the 60's some F-100's had a Dana 60 semi-float rear axle, probably just as "unique" as your GMC rear end, but may be another source for cross referencing parts.
I don't know what size the brakes are but I am guessing they are smaller than the regular brakes on a full floater Dana 60, otherwise you could just use those parts. I know the hubs and drums would be different but you may be surprised at how much of the stuff from the baking plate out may interchange.