Blown up rear axle, what years fit?

[JLeather]

My Dad's been driving my '98 K2500 for a couple months while his truck was getting fixed up. Today he called me and said the rear blew something out the diff cover and locked up while he was driving it. Won't know for sure what went til I get it opened up, but I'm anticipating the worst and that I'll need a donor axle so I'm gonna start hitting the yards around here. Truck is a 1998 K2500 8-lug with the 8600lb GVWR and the big rear brakes. What other years/models fit? Do the 2500 8-lug suburbans also have the same rear? Did some come with 8-lug but not the big brakes, and can I swap the brakes? Brakes were all new in the rear last year, so I'm planning to swap the brake parts over anyway.

 

[Biggershaft96]

all the gmt400 rear ends are bolt in swaps. some came with semi float rear ends, some came with full float rear ends nut all the 2500 and 3500 rear ends were 14 bolts after 93? i think it was. idk if there was any specific rhyme or reason as to which truck got which axle so make sure you know which one you need before you hit the junk yard. also it was more than likely the g80 that failed.

edit: also im 99% sure the hub to hub width was different on 2x4 vs 4x4 trucks

 

[454cid]

You probably want an axle with the JB8 RPO code. Some of them are JD7. I believe the Suburbans are usually JD7. I think the JD7 brakes use the narrow shoes, but also have the drums behind the hubs, which means pulling the axle shafts to get the drums off.

 

[JLeather]

I think I have the semi-float. I don't have to pull the axles to get the drums off. Also if the truck had a G80 it never worked. I know it'll spin (or rather would spin) one tire on wet grass. I'll have to check the ratio and see what the damage is.

Can I put a 2wd heavy rear in it even if the width isn't quite the same? I've got a line on a '95 C2500 rear with 8 lug.

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[Gibson]

It was possible to order a K2500 Suburban, (8,600 gvw,) with a FF 14 bolt,, but the standard axle would have been a 14 bolt simi-float with JD7 brakes.
The JB8 brakes have shoes that are a 1/2 inch wider, and were usually found on the 9,200 gvw pick-ups with the FF axle,, (basically a 3500 with single rear wheels).
'Course, just about anything is possible given the rpo option list that was available to the original buyer.
I have seen two GMT-400 Suburbans in the year range that you're talking about, that had FF 14s,, a '96 with JD7, and the other, it was either a '97 or a '98, had JB8 brakes, but I think that the JB8 one might have been a swap.

 

[454cid]

JB8 brakes are 13"x3.5", the narrower 13" drums are only 2.5".

 

[bamabound]

Aside from brakes it is of utmost importance that you know what ratio you have because it has to match the front. If you're not sure the codes are in the glovebox and if the sticker is rubbed off you can go to an GM dealer & ask for an RPO printout. Here's a list of codes for rearends. http://www.rpocodes.com/GM-RPO-codes/gmrpocodesGthroughM.html

 

[JLeather]

The axle is a GT4 code (3.73). Might not need a whole axle though. Turns out what happened is that one of the pin/bolts that holds the spiders in backed out. The truck dropped a spider gear and that's what blew out the back of the cover. Wrecked all the spiders, but the r&p is fine and I haven't found and damage to the carrier yet. If there's no damage to the carrier I should just be able to put new spiders and hardware in it.

Anyone ever heard of this happening before?

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[JLeather]

Too optimistic. Carrier is cracked, although R&P look fine. Pricing parts out (carrier, spiders, hardware) vs junk yard rear now.

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