"New" truck with a lot of issues.
 

I bought a truck over the weekend and I pick it up later today. It's a '71 3/4 ton LWB with 350/4 speed. I know it runs and drives, but I haven't driven it yet. I sold my truck over the weekend because I missed my redneck 4x4. I found this truck while I was at a tow lot buying a sports car and couldn't say no.

The first issue is the driver side axle shaft is busted. They pulled the shaft out and t looks like it's not too tough to replace based on the repair guide. It's a Dana 44 front.

My question is what rear axle came in these trucks? It's a large and very round differential with 10 bolts (not a GM 10 bolt) with 8 lugs.The owner had no idea what it was. I'll be posting pics later this week when I get it home and get it cleaned up.

Anyone have an axle ID page with pictures? Thanks.

<edit> Never mind. It's a corporate GM 10 bolt. Found it here.

Re: "New" truck with a lot of issues.
 

You don't have a 3/4 ton 8 lug 10 bolt axle. They never made one. What you probably have is an eaton 3/4 ton axle. The eaton axle is the early cousin of the 14 bolt axle.

It's not a bad axle at all. Easy way to tell it's a eaton is to look on the front side of the axle. If the center section (3rd member) is removeable you have an eaton.

Re: "New" truck with a lot of issues.
 

Was it stock on these trucks? Should I keep it or swap it out for something more standard?

Re: "New" truck with a lot of issues.
 

That is a loaded question, depending on who you talk to. I like my eaton, its tough and a little different, others will complain about parts availability vs. a 14bolt ff rear axle. I was fortunate enough to come across a 4.10 rear locker third, and in a matter of a couple hours (total....see comment about parts availability) I was able to swap from 4.56 open rear to a fully locked 4.10 rear.

To answer your question about was it stock, I believe it was stock on 3/4t and 1 ton's from the 40's (?) until 1972. I have seen 71-72's with dana rears, and it seems like almost all GMC's got dana's exclusively for the 67-72 models (could be wrong, always seems to be exceptions).

All in all, if the rear is sound, I say keep it, give it a thourough cleaning and some synthetic fluid, and it should run forever....just be prepared for a disc. swap when it comes time for a rear brake change.

Re: "New" truck with a lot of issues.
 

I think that I have an axle for you. 1/2 ton and 3/4 ton Dana 44's should be identical except for the spindles and out. Pretty easy to remove too...

1. Take off lockout hub,
2.remove hub (requires a funny looking socket found at autozone)
3. remove six bolt holding brake bracket
4. remove it and the spindle (use a lead hammer if it's stuck, you'll damage the threads if not.)
5. pull axle shaft all the way out, no C-clips to mess with, don't even open the diff cover!

Let me know if you want the axle... I'm easy

Mike

Re: "New" truck with a lot of issues.
 

The Eaton HO52 is arguably the best damn rear ever made.I found parts for mine.

Re: "New" truck with a lot of issues.
 

I could have swore I read somewhere that you can use 14 bolt axle shafts on the eaton if you also change out the side gears to match. Not that I heard too many eaton full floater axles break but if one wanted to beef one up with a higher spline count shaft they might be able to.

Did anybody else see that somewhere too? I thought it was one of the 4wd mags.

Re: "New" truck with a lot of issues.
 

I seem to remember hearing something to that statement before, I think it was in reference to installing a 14 bolt locker into an eaton third, and using the 14bolt axles to make the whole thing work.
I am VERY pleased with mine thus far!

Re: "New" truck with a lot of issues.
 

I guess I'll keep it unless it has issues. I get to drive it home tonight, I could only drive one car at a time.

I miss my street truck, but the redneck 4x4 will fill that hole nicely. I will post pictures this weekend, it's quite a sight. There is a gas tank mounted in the bed, and one mounted on the drivers side. The dash is busted up (but I have a replacement), half the gauges aren't hooked up, and the door panels are recovered in diamond tuck.

At least it will keep me busy for a while.