K2500 Suburban Rear Axle Replacement

[LikeABoat]

Hi all, first post, awesome site!

I have a K2500 suburban, 7.4L, 4wd, full floater 10.5 ring gear rear axle that has a bent rear hub after an accident, vibrates at 65mph, I've confirmed its the right hear hub. So, I want to replace the rear axle or just the hub and axle. I haven't been able to find a direct replacement from another suburban. So, my questions are 1) why does the salvage yard computers show that 3500 single rear wheel trucks or another 2500 suburban are the only options. 2) Is 2500 truck full floating different , 3) will a hub and axle shaft from the 2500 fit on my axle?

I've measured and they seem the same. I tried reading and have found 1/2 don't interchange because 1/2 ton suburbans have rear sway bars, my 2500 does not. I haven't been able to find these answers and would appreciate any help. Thanks.

 

[stutaeng]

The reason may be because the 2500 (8 lug) with 5.7 had the 9.5" semifloat 14 bolt, whereas the same truck with 7.4/6.5TD had the 10.5 full float 14 bolt. I think this applies to 2500 Suburbans as well. On the 3500s, they all got the 10.5 full float 14 bolt, regardless of engine. As far as I know, this is true on the Vortecs. I've read here that some early GMT 400 were different, so can't confirm this on the 88-94 models.

And I "think" the axle for 2500 Suburbans and 2500/3500 trucks are the same; obviously, comparing 9.5 to 9.5 and 10.5 to 10.5. Someone with more knowledge may want to confirm this.

The 1500 suburbans didn't have the 14 bolt, except perhaps only the 6.5 TD. I don't know for sure on that one. Better to stick with a 7.4/6.5TD truck. Better check twice before buying the axle anyways.

Welcome neighbor!

 

[Steve Addy]

IDK who's telling you what will interchange but they're wrong. You should be able to acquire a hub / axle / anything off the Express or Savana vans (3500) up to and including 2002. After that they all went disc. And as far as that goes you should be able to get it off any 3500 with 10.5" rear axle as long as it's not DRW. I'm assuming you have JB8 brakes so just look for that rpo code in the donor and you'll get what you need. Vans have rpo codes in right side door jamb.

I just went down this road with my C3500 that I purchased, where the rear wheel / drum fell off on their kid and the parents junked the truck...at 101k miles mind you. Forget that it was probably the kid / dad's fault.

At any rate I got replacement parts (drums / hubs / axles) from a 3500 Savana 2002 and it was all identical.

I have extras from the repair (hubs / axles) but I would bet it would be costly to ship them although IDK that for certain.

Find vehicles with the FF rear axle is more of a challenge now but only because of age and because they switched everything to disc.

Steve

 

[454cid]

It's probably the brakes. GM used several brake RPOs on the 10.5 axle. Suburbans didnt normally get JB8s with the slide off drums, that I've heard. I think they normally use the JD7 rpo.

Edit: your SPID sticker with the rpo codes is in the glove box.

 

[LikeABoat]

I have JD7, but I don't really know what the difference is.

If all 2500 truck 14 bolt, full floaters are JB8, would it swap and bolt in?

 

[LikeABoat]

I tried to look up JB8 vs JD7. Seems JB8 are 10,000 lbs GWV. But savage yards tell me the 3500 14 bolt, 10.5 SRW trucks would work, but not the 2500 trucks. So confused.

 

[LikeABoat]

Here is a picture of my drum

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[stutaeng]

My K3500 SRW I believe has the JB8 RPO code. The SRW were 9200 lb GVWR.

If it's just the brakes, could OP just swap the entire axle with JB8? Only drawback would be more work and bleeding brakes. Need new U bolts, so will be more costly as well. Then he's got to worry about axle ratio...um, maybe too much work!

Not sure if he wants that? Just throwing that out there.

 

[Steve Addy]

I have JD7, but I don't really know what the difference is.

If all 2500 truck 14 bolt, full floaters are JB8, would it swap and bolt in?

Hey all
JB7 and JD7 are the brake codes for 14 bolt axle, either SF or FF, one is hydro the other not, but they have the 13x2.5" brakes.

The JB8 brakes which are hydro 10,000 have 13x3.5" shoes and 4" drums. Not all SRW 3500 were 9200, mine is labeled 9000 gvwr for some reason.

If the axle housing is not bent then I would not replace anything other than the pieces that are damaged. If you can get by with new hub and / or axle shaft then go that route, you should be able to reuse everything else I would think unless other parts are damaged.

Hope this helps, didn't mean to make anything more confusing. I had to dive in depth on this when trying to round up parts for my C3500 6.5TD.

Also, I believe on the brakes that JB/D7 differs from JB8 only in drum, backing plate and brake shoes. Everything else appears to be the same. To accommodate the extra inch of shoes they used a backing plate that recessed in further and a drum with larger surface area to allow for the 3.5" brake shoe.

Otherwise I don't think there's any difference in the other pieces, ie hub, axle etc, so if your brake drum and backing plate are ok then all you need to do is find a FF 10.5" axle and snag the hub and maybe the axle from that side.

Steve.

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[HotWheelsBurban]

I believe JD7 is the hydroboost 13 x 2.5 shoes. @Pinger has a 99 C2500 Burb that he's done a lot of rear brake work on, that is that brake code. But I don't remember if his Burb has a full floater rear axle or not. My only 2500 Burb had a semi floating axle, but it did have the big ass brakes. He's in Scotland, so he may be on the forum now....