Chevy & GMC Vans

Hey Guys,


I have a custom 97 GMC Safari that I do car shows with all over. My issue is the rear axle. First off, I do have an air suspension setup. I broke an axle months ago while driving. The driver side axle tube seem to come out from the differential. Well, I put in another rearend and this axle seems to be bending as well, or appears to. You can see that the wheels are pointing in and Im afraid it will break like the first one. What are my options because this is dangerous, expensive, and just plain annoying. Weight wise, I do have a big stereo but it is definitely under the weight of say 8 200 pound passengers. Any help is much appreciated.

I was thinking maybe a one ton axle from a 3500 savana or something along those lines if it has same bolt pattern and no mods to be made.

You wont just be able to bolt that 1 ton chevy van axle in with no mods.
Astro differential is offset to the right a few inches, and narrower width overall.
There is an older Ford Econoline that used a beefier axle that also has the correctly offset pumpkin, and the right spring perches.
It bolts right in, The ford 5x5.5 lugs would need to be redrilled for a chevy pattern, but thats about the easiest beef up axle you might find.
The ford econoline year for them was late 70's, early 80's I believe. And it was either a 9" or a dana 44, I forget.
There are others who have done it, and threads out there on the subject.

I hear a ford 8.8 from an explorer bolts into an S10, but it has axle under springs, astro is spring over.
I'm not sure why yours are breaking, got a big block chevy in there or something?

I just have the stock 4.3 in it and stock transmission. All I have is weight from audio setup but I would say its only 800 pounds max and evenly spaced. Im thinking I may have gotten a bad axle for the second time. The first one broke from years of vibration I beleive. I forgot to mention the air bag kit uses the bolt holes on the diff for 2 of its links so bolt pattern will matter there too. I can always weld around that issue though. The thing I cant change is rim bolt patter. Rim sponsors are strict and Im stuck with 5 on 5.

If you still should decide do do an axle upgrade of some sort feel comforted by the fact the redrilling for new wheel lug pattern is about the easiest mod you will run up against.
so if you were to find an axle that can just bolt in, the redrilling for 5x5 lugs is really pretty easy and/or cheap.
If your happy with stock, just try to get the newest lowest miles axle you can find. Disk brakes might be nice as well, from a 2003-2005.

Weld on an axle truss.





Or maybe try one of those cheesy bolt on types. PM me for info on the truss it you're interested. Not sure if you have space for it or not.

WOW, now that's a truss. A bit overkill for what DJ needs. I don't think the weight of his equipment is the peoblem. I carry 800-900 lbs of balloon equipment. It's in the van 24-7 and has been for nearly 10 years. The weakness of these rearends (ring and pinion gears) is a common problem. I know several people who have had to replace or rebuild them because of this problem. That would include me. So there's a custom built 12 bolt that now resides under the van. I've never heard of your problem, DJ. I don't have a solution other than a custom built rearend. It will be pricey but if you keep your van for several years then it may be worth the expense.

If the top 2 links are attached to the center section, you will need to weld in a truss to beef it up. Where are the air bags mounted? Throw us up a few pics as it will help us to figure out the issue. I am sure it's not the weight but is tied to the air bag setup.

As for a relatively easy axle swap, there isn't one. A Ford 9" from an Econoline van will fit but you will need to modify the axle to fit your link setup as well as wheel bolt pattern and the driveshaft will need to be modified too. You could have a custom GM 12 bolt or 9" built but they are expensive. A couple guys have done it on here.

I'm getting kinda tired of these weak GM 10 bolts too, and I've been pondering what to do.

If you don't mind a bit of modification, I am starting to think the ford explorer 8.8 axles might be worth further investigation.
The S10ers can bolt it straight inplace of thier GM 10 bolt, then buy a special u joint and the stock drive shaft was working for them.

So. if the width works for an astro, it would need the springs over instead of under, the lug pattern re-driiled, and a u-joint adapter.
They are way beefy compared to as astro 10 bolt. They come with disc or 11"drum, some real nice gear ratios, and an optional L/S that isnt a G80 Govbomb.
Apparently they are within about 3/4 inch width of a 4x4 s10 Axle, and have the pumpkin offset 3" to the passenger side, and can survive fine in a 9 second 1/4 miler.
One thread I was reading at S10, specifically said the 8.8 pinion depth was the same as the 10 bolt. which is good for the driveshaft.
I haven't gone and measured anything yet to see how the s10 axle compares to an astro axle in reality instead of theory, but it sounds promising.

http://www.s10forum.com/forum/f13/i-hav ... ap-490096/
http://www.s10forum.com/forum/f213/ford ... es-509326/

The S10 axles are much narrower than the Astros. The Astros are a full width the same as 1/2, 3/4 and 1 ton (SRW) trucks. The Explorer axles are too narrow. They also work great for Jeep Wrangler swaps as they are narrow too. If you found an 8.8 from an Econoline van, it may work.

Thanks Dean. Do you happen to know what an Expedition has in it?

The expy's with the small 8 had the 8.8 and the ones with the 5.4 had the 9.75" axle. At least it seems I remember looking at their rears when I have followed them and noticed this. I checked Randy's ring and pinion and it confirms the 2 different axle choices. The later years are IRS.