Suburban rear axle into C1500?

[someotherguy]

I'm no engineer so this is surely second-hand info, but talking with a local differential builder, he feels like the 8.5" actually got *weaker* when they upped the spline count on the axles. Says they didn't change the carrier design to allow for it, and the carriers are bad about splitting (not enough "meat"...) Really don't know how accurate that is but we were just having a discussion about it and he wasn't trying to sell me anything, so take it for what it's worth. We have certainly seen plenty of 8.5" G80 carriers blown the hell up into a million pieces, but he acted like it was all of them, open carrier and G80.

But in short, yes, in several aspects it is a very light duty rear end and not suited for even medium or heavy use, and definitely not any abuse, under a full size truck.

Richard

 

[sntrym]

For a DD with some towing, the 10 bolt is fine. Don't overthink it. If you're gonna beat on it, go 12 bolt. On my old truck, the 10 bolt chipped 3 teeth after 306k miles. On the truck before, it had 196k on it when I sold. On my current Yukon, I replaced the gears and added a TracRite from AAM at 240k.

All of these trucks tow, mostly around 6000lb on a regular basis with the supposedly 'weak' 4l60e too. If you're not going to beat on it, the 10 bolt is fine.

 

[1989GMCSIERRA]

Thanks for the info! A 6 lug conversion seemed like it was inevitable when I got the truck, all the wheels nowadays are 6 lug and run a 16 inch tire. I’ve been trying to avoid it so I don’t have to buy new rims....but maybe that’s an excuse to get 16” or 18” torq thrust wheels I’ve been eyeing

Maybe this is a dumb question...but what is it about the 10 bolt that is so bad for it to have garnered such hatred from this fine group of enthusiasts?

it’s considered weak because when people hammer on them they tend to break. I’ve had my “weak” 10 bolt with 4:56 and 4:10 gears. Have a Auburn locker and ran 33s and 35 inch tires. I’ve yet to have a issue. But I simply dont hammer on my trucks. The axle is the original axle that came with my truck. I rebuilt it once at about 130,000 and currently have a total of 400,000 miles on it. When I say rebui,t it it was rebuilt because I wanted to put 35s on it not because it needed rebuilding. I simply service it at the right times and that’s pretty much it.
I switched from 4:56 to 4:10s beciase I went from 35s to 33s. The 4:10s are a better street gear as I can run. 31 tall tire with it’s having to regear. If o switch to a 275/60 I may have to go to 3:73 or 3:90

the issue you’re gonna have is the rwar axle will have a different bolt pattern so you need to grab the spindles and front brakes and calipers to make the front end a 6 lug also or you’ll need to get some spacers with bolt pattern stud conversion.

it really depends on how do you plan on using the truck. Are you gonna hammer it on racing and drag races or just cruise?
If you get a junkyard axle I would look at it and measure and bring a straight edge. Junkyard axles can be bent or just hammered. I would drop the rear cover right there and check the guts. Any metal shavings or broken gears leave it.
be very careful when choosing junkyard axles. Check them over really well. If you do a junkyard axle I would go and rebuild it from hub to hub. Because you have no idea what shape it’s really in. A regear and bearing kit is cheap insurance. Yiu don’t wanna pull the axle twice. Three times if yiu count the initial pull from the yard.

 

[Jerryred94silvy]

Excellent info, thank you. I agree with rebuilding the junkyard axle, I kinda planned on doing that since it would be easier out of the truck than in it as well as what you mentioned: not knowing what shape it’s in. I also don’t hammer on my truck. I sometimes do stoplight “races” against my buddys 2nd gen Cummins....but considering I can gap him at part throttle I wouldn’t consider that “abuse” on the truck

The truck is also a 2wd, so if I need bigger tires for anything I’ll get a truck/suv that is more suited to having bigger tires and off roading and whatnot. With all that said, I don’t see why a 10 bolt would explode under my truck.... Unless I’m just THAT unlucky lol.

 

[someotherguy]

the issue you’re gonna have is the rwar axle will have a different bolt pattern so you need to grab the spindles and front brakes and calipers to make the front end a 6 lug also or you’ll need to get some spacers with bolt pattern stud conversion.

Front just needs rotors from a 7200lb GVWR C2500. The spindles and calipers are the same. Rotor is too, other than the bolt pattern.

Richard

 

[Schurkey]

You're going to all the effort to change axles...why would you put in the ****** one? Especially if you have to "rebuild" it?

Get a 9.5" in decent condition, with the gear ratio you want. Measure the backlash on the gears. From there, adding a posi carrier means you don't have to dick with the pinion gear. Which means that all you have to worry about is backlash and bearing preload. Transfer the ring gear to the new carrier, press new bearings onto it. Slap the carrier into the housing and check backlash. Once the backlash is exactly the same as it was before, set preload. Put axle seals in, "just because". Fill it with grease. Done.

If you're not changing the carrier, it's even easier.

If the axle is carefully selected/inspected before purchase, you wouldn't have to do anything to it beyond installing fresh grease, and verifying that the brakes are in good condition--drum interior not rusted, shoes still have life, wheel cylinders not leaking.

For the record, the 9.5" axle has a 14-bolt cover, and is usually described as a "14-bolt" axle.

 

[1989GMCSIERRA]

Front just needs rotors from a 7200lb GVWR C2500. The spindles and calipers are the same. Rotor is too, other than the bolt pattern.

Richard

ok. I didnt realize that the newer stuff swaps that easily.

That front rotor swap is just starting the cost run up. You still gotta buy

rear axle complete ($400 average)
Rebuild kit for axle ($200)
Ring and pinion kit ($250)
installation of kits labor ($800)
Installation of the axle labor ($400)
Ubolts ($40)
Possibly joints ($30)
Front rotors ($140)
Brake pads (60)
Wheels ($600
Tires ($600)
If you diy you need tools to set up the axles, calipers, dial guage, torque wrench, gear oil, brake fluid, seal puller and drivers, bearing puller and driver, shop press for the carrier etc.

average prices. Deduct labor costs if you can diy. Most can’t and have to pay, the average cost to rebuild a axle is $1500.

And that’s a crap load of money spent for replacing something that simply isn’t that unreliable. Like I said these axles seem to last just fine under plenty of GMT400s built for 10 years driven for at least 20 years as long as you aren’t a moronic idiot. Ive seen guys break Dana 60s. Doesn’t mean the axle is weak. It just means the owner asked the parts to do more than they were designed to do.

I’ve had my original axle in there since the truck was made. It’s been rebuilt once only because I had big tires and it came with 3:08 gears. And 35s...gears just weren’t cutting it.
it lasted for years with running 35s a d 33s. I went back to stock size tires which means I’ll be regear it again. But I’m not swapping axles.

it really all depends on how much he plans on using his truck. If he’s gonna race and hammer it yes swap to bigger stronger axles. If he just plans on cruising it and light duty leave the axle that’s there and save your money.

 

[someotherguy]

Who the hell is paying someone labor for this work?

If you can't do it yourself, you've already lost.

"Most can't and have to pay" - you do realize you're on a truck enthusiast site, right? While degrees of capability vary, I would be willing to bet most here are more than capable of the work described. Sell 'em short if you like, but I won't.

I could further dissect your analysis but it's pointless. You've greatly overestimated what is required, in your effort to understimate the need for a stronger axle.

Richard

 

[Schurkey]

You still gotta buy

rear axle complete ($400 average)

I won't argue that. That's about what I paid. I'd have gotten it for less if I needed 3.73 gears, but 3.42 and G80 was tougher to find.

Rebuild kit for axle ($200)
Ring and pinion kit ($250)
installation of kits labor ($800)
Installation of the axle labor ($400)

Select a good axle, you don't rebuild it.
Don't buy a ring and pinion kit, because you're not dicking with the pinion. He'd need a pair of side bearings, and perhaps some shims. He'd need access to a dial indicator to measure backlash, which is probably available as a loaner-tool.
And, yes, I expect him to install the posi carrier, and axle himself. If he doesn't have a decent, ACCURATE torque wrench, he shouldn't be on this site.

Ubolts ($40)
Possibly joints ($30)

I think you may be low on the U-bolts, but he only needs the rear U-joint. $70 is probably not far from the truth.

Front rotors ($140)
Brake pads (60)
Wheels ($600
Tires ($600)

Get the rotors, pads, wheels and tires from the truck that's donating the axle. Or at least, from the same Treasure Yard. I bet he gets everything he needs for a grand--including the axle.

If you diy you need tools to set up the axles, calipers, dial guage, torque wrench, gear oil, brake fluid, seal puller and drivers, bearing puller and driver, shop press for the carrier etc.

The press to install the carrier bearings might be a genuine consideration. He'd maybe have to pay a shop to press the bearings.

The rest is pretty tame.

Some of this really does depend on finding a suitable donor vehicle; or a Treasure Yard that will work with him to sell a "package deal". I looked a long time for a suitable axle; but I wanted an axle I didn't have to change carriers on; and Gov-Lock was just fine with me in a 9.5 axle, where it wouldn't be in an 8.5.

OTOH, I'll be doing a carrier upgrade on my '97 K2500 (10.5 axle) this summer. Who the hell buys a truck to plow snow, and doesn't check the box for a locking rear axle? So again, I'm not planning to rebuild the axle. I'm going to push bearings onto a new carrier, transfer the ring gear, match the backlash, and torque the caps. The pinion doesn't leak, and I'm not going to touch it.

I will inspect the brakes while the axle shafts are out--being a full-float axle, getting the drums off requires a heap of work that doesn't need to be done on an 8.5 or 9.5 axle.

 

[1989GMCSIERRA]

Who the hell is paying someone labor for this work?

If you can't do it yourself, you've already lost.

"Most can't and have to pay" - you do realize you're on a truck enthusiast site, right? While degrees of capability vary, I would be willing to bet most here are more than capable of the work described. Sell 'em short if you like, but I won't.

I could further dissect your analysis but it's pointless. You've greatly overestimated what is required, in your effort to understimate the need for a stronger axle.

Richard

Don’t assume a enthusiast translates to a wrench turner who has the tools and knowledge on doing the required work.

Who is paying someone for the labor?...Plenty of enthusiasts don’t build axles. In fact I’m betting the large majority of enthusiasts do not do their own axle work. Just like plenty of enthusiasts dont rebuild engines or transmissions. Just because someone likes cars and is on a enthusiast site doesn’t mean they have a full shop with all the tools or the know how to do all the aspects of car mechanics.

You are assuming the parts you’re getting are In good serviceable condition. Most GMT400s I come across in the junkyard are beat to hell. Considering the condition.....I’m bettung the maintenance wasn’t top of the list.

Dude people barely remember to change the oil in their cars and you think theire gonna remember to change their axle oil.

Hey if you’re the type who likes getting under a truck and constantly fix crap be my guest ....run around the junkyard buying all the old parts. Saving yourself a few bucks. But you can’t really tell the condition of a part. And you’re buying a used axle with unknown history.

persinally I would never just throw a old axle in a truck and call it a day. But to each his own.

I won't argue that. That's about what I paid. I'd have gotten it for less if I needed 3.73 gears, but 3.42 and G80 was tougher to find.


Select a good axle, you don't rebuild it.
Don't buy a ring and pinion kit, because you're not dicking with the pinion. He'd need a pair of side bearings, and perhaps some shims. He'd need access to a dial indicator to measure backlash, which is probably available as a loaner-tool.
And, yes, I expect him to install the posi carrier, and axle himself. If he doesn't have a decent, ACCURATE torque wrench, he shouldn't be on this site.

As stated above being a enthusiast doesn’t necessarily mean you’re a mechanic shop in tools and knowledge. So a new enthusiast just learning and doesn’t have the tools to do a lot of the work doesn’t belong in this site by your statement. I know when I first started doing work on my cars I didn’t have a torque wrench. I eventually bought one. Now I got four toolboxes full of tools, a four post lift and can pretty much rebuild anything from two strokes to diesels


I think you may be low on the U-bolts, but he only needs the rear U-joint. $70 is probably not far from the truth.

Possibly. I just threw a average price. My u bolts for my F350 when I swapped blocks were $80. But they were taller as I was going from a 2 inch to 3.5 blocks. And I had a D80 cause it’s a Dually which I couldn’t buy over the counter. I assumed in a stock 1500 set of u bolts couldn’t run more than 40 bucks. U joints maybe $30 for a Dana/Spicer. I wouldn’t put some Chinese trash on my vehicles.

Get the rotors, pads, wheels and tires from the truck that's donating the axle. Or at least, from the same Treasure Yard. I bet he gets everything he needs for a grand--including the axle.

ok. Let’s assume he finds a decent axle. What’s the axle gonna have on it as far as wear. Assuming 12,000 miles a year you’re still looking at a axle with 240,000 miles. Let’s hope the owner was a enthusiast and changed the gear oil...at least.



The press to install the carrier bearings might be a genuine consideration. He'd maybe have to pay a shop to press the bearings.

sure....most shops will probably charge a hours labor.

The rest is pretty tame.

Some of this really does depend on finding a suitable donor vehicle; or a Treasure Yard that will work with him to sell a "package deal". I looked a long time for a suitable axle; but I wanted an axle I didn't have to change carriers on; and Gov-Lock was just fine with me in a 9.5 axle, where it wouldn't be in an 8.5.


this imo is key. How long are you gonna search for that unicorn well maintained axle? Or that yard who will work with you. I have about 10 yards within a 30/45 minute drive. None will give you any deal other than listed price. Unless it’s a special sale day 30/40% off. But they raised their prices so used parts are more expensive now. IF you can find that unicorn axle and can just R&R with no work....ok...but the chances of that happening.....

OTOH, I'll be doing a carrier upgrade on my '97 K2500 (10.5 axle) this summer. Who the hell buys a truck to plow snow, and doesn't check the box for a locking rear axle? So again, I'm not planning to rebuild the axle. I'm going to push bearings onto a new carrier, transfer the ring gear, match the backlash, and torque the caps. The pinion doesn't leak, and I'm not going to touch it.

I will inspect the brakes while the axle shafts are out--being a full-float axle, getting the drums off requires a heap of work that doesn't need to be done on an 8.5 or 9.5 axle.

I personally think that the stock 10 bolt axles on 1500s get a bad rap. Mostly because people hammer on them abuse abd neglect them. So when they break ....it’s a weak axle. I got 396,000 miles on a factory axle I rebuilt at 120,000 because I went with bigger tires. So about 280,000 miles on the rebuild, but I change the gear oil, fixed a axle seal, obviously brakes. Never had a issue. Still have the truck. And 250 of those 280k was running 35s. The 30k was running 33s.

either way you guys are assuming OP can build his own axle has the tools and knowledge to do all the required work. If he does he’s money ahead.

Most enthusiasts I know love cars. But none of them can actually work on them other than typical basic maintenance and brakes being a relatively in depth repair. But they still love cars