Replacing part of an axle tube.

[stutaeng]

Well, about that, I had another axle sitting in my backyard... but it was for a GMT800. It's NOT a direct swap. Otherwise, it would have been a donor axle.

However, on THAT note, that GMT800 axle also has an Eaton Posi carrier that I installed years ago. Both axles are 8.5 inch 10 bolts, both are 28-spline, both are drum brakes, and both are 3.42 gear ratios. So explain why the axle shafts on the 800 are longer and carrier bearings were a larger outer diameter.

Well, that's just because the GMT 800 WMS was different (68.5" IIRC?)

The later 10 bolt is technically a 8.625 (simply called a 8.6"). I thought they were actually almost the same (or similar enough to be interchangeable?), and that one just required some thicker shims?

I really don't know the details on that, but the ring gear/pinion and master install kits are usually listed as compatible with 8.5/8.6 axles.

 

[thinger2]

What is this part called and is there a replacement available, or am I going to have to patch up the old one? I'm about to pressure wash and sandblast this overweight piece of garbage, so I already know that the rot will be worse when I'm done.

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Its done. By the time you blast it and clean it back to solid metal you have nothing left to weld to.
The perch isnt the worst part of it, though it is really bad.
The hole in the axle tube is rotted from the inside.
That tube keeps the wheel bearing in place and keeps the wheel and the brakes and everything else attached to the truck.
If that axle tube breaks while you are driving everything will shred off of the back of that truck.
Wheel, tire, brake caliper all of it.
It will pop the axle right out of thd diff and spin you while it tears the truck apart.
And dont forget about what happens to the innocent victim that gets hit by your random flying wheel, hub, brake ,axle assembly when it shreds itself and starts bouncing down the road.
All while you are pinballing through traffic on three wheels.
Dont **** around with something like this.
If we drive old vehicles we have a responsibily to make sure that they are not a danger to our famiies or to other people.
That is a part of what we do.
That is the very basis of car culture and the very basis of hot rodding and modding a car.
At least it used to be.
Anything else is dangerious hillbilly dont give a **** tractor welding.
Maybe you can hack that back together.
But are you readdy to deal with the life altering penalty if you are wrong?
That is the question.
In racing I know that I am pushing to go faster.
More prop, less wing, More air under the boat, too much air less wing different prop.
Think ill start smoking again.
That is a part of racing anything.
But That is a well thought out risk.
And nothing is half assed.
But these farmer weld knuclekheads
think its okay for you to crap weld that and run it down the freeway.
It is not.
In America we have tracks where you can just show up and pretty much run any piece of garbage you have.
Which is really fun.
Buy a helmet, buy a **** wagon and run it.
We play that game on the track.
Only morons who dont understand how ****** they will be if they wreck play that game on the public roads.

 

[Frank Enstein]

8.5/8.6/8.625 went to 30 splines on the axle in 1989. They have always been 30 splines on the pinion.

 

[DeCaff2007]

I hate to have to put it this way, but it seems that the parts of this truck that I try to save, I get more critical feedback than I do supportive.

Actually, I can't even say that, because the rules here in the rust belt are different than the rest of the world. Basically, as long as it passes inspection then it's good to go. People around here will rivet three different chassis' together just to have a winter beater for cheap.

Can't wait to see what happens when I pull the cab for floor pan repair and body bushing replacement.....

 

[454cid]

I hate to have to put it this way, but it seems that the parts of this truck that I try to save, I get more critical feedback than I do supportive.

Actually, I can't even say that, because the rules here in the rust belt are different than the rest of the world. Basically, as long as it passes inspection then it's good to go. People around here will rivet three different chassis' together just to have a winter beater for cheap.

Can't wait to see what happens when I pull the cab for floor pan repair and body bushing replacement.....

The difference is you're not doing anything for the structure of the tube. You've removed the rust, and repaired the rusted bump stop, but that won't do anything for strength just driving down the road. If you were doing something like replacing the tube, that would be different. You're cleaned up axle is going to be no better than when you started strength-wise.

This isn't a case of southern rust panic syndrome. I'm from MI, Derek is from MI, and you've got two guys from WI, that know better than I do about axle repair (I've built them, but never repaired them).

 

[RichLo]

I just looked at your pictures again and this is scary. Dont use this axle! If it was just the plug weld cracking you could weld the axle tube to the diff housing like I had in my previous reply. But this is not fixable without replacing the whole tube! Cut your losses on this one and find a stronger 6-bolt axle.

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[DeCaff2007]

I just looked at your pictures again and this is scary. Dont use this axle! If it was just the plug weld cracking you could weld the axle tube to the diff housing like I had in my previous reply. But this is not fixable without replacing the whole tube! Cut your losses on this one and find a stronger 6-bolt axle.

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Fair enough. I'll admit I didn't like how that looked, but the cheapo in me said "Ah, it's just surface rust, no harm no foul". I went ahead and primered/painted it, and I even found some special order bearings that will let my Eaton Posi carrier work with a GMT400 axle, as opposed to a GMT800 axle.

However, I have not actually installed anything in this axle yet as I'm waiting on additional parts. If I have to eat the cost of materials, in the name of safety, then so be it. At least I got some good sandblasting practice in.

 

[RichLo]

If you already have parts for this axle, there are millions of these out there for cheap. Any junkyard should have a bunch of them to choose from. You know what to look for now, lol. Bring a pick or small screwdriver to pick at rusty spot to see how deep the rust is and go through the same steps you did with this axle. If the junkyard offers some exchange warranty that would be perfect for an exchange after sand blasting if you find another deal-breaker.

If you have the ability, I would still weld the tubes to the diff housing on any axle that is being swapped. Cheap insurance as I saw first hand how weak those factory plug welds are, check out my thread that I posted earlier if you haven't already.

 

[Supercharged111]

I hate to have to put it this way, but it seems that the parts of this truck that I try to save, I get more critical feedback than I do supportive.

Nobody here is being critical to be a djck.

 

[DeCaff2007]

Nobody here is being critical to be a djck.

That actually puts my mind at ease. Thanks for that.

In the meantime, since I'm now shopping for an axle, I may as well find a positraction replacement for the open rear in my 83 Grand Prix. That, however, is NOT an 8.5" rear.