Rear Differentail for a 90 2WD Suburban

[eagle mark]

The rear axle is going out in my 1990 Suburban with 5.7L TBI 700R4 drive train. I think it's a ten bolt rear.

I need something bigger and better for towing all the time. What else is available five lug? Or what else is available that I may use an adapter or look for simalar wheel if it's six or eight hole.

 

[sweetk30]

i would go look for a 14 bolt semi float from a 454ss truck.

9.5" gear and 5 lug .

will need to do a few mods to install.


or you can go 14ff and get the conversion hubs to 5 or 6 lug pattern. but then you will need to do disk brakes .

 

[thorguy57]

That easy. Get a 8 lug 14 bolt and knock 3 studs out of each hub. Instant 1 ton 5 bolt. Of course I am just kidding.

 

[eagle mark]

i would go look for a 14 bolt semi float from a 454ss truck.

9.5" gear and 5 lug .

That would be excellent! Bet if anyone that owns one won't sell it! So did they come in anything not so rare and collectable?

 

[eagle mark]

or you can go 14ff and get the conversion hubs to 5 or 6 lug pattern. but then you will need to do disk brakes .

Don't really need disc brakes or the expense of all this. Gota be a cheaper way.

 

[tRustyK5]

Find a 6 lug 14sf and get some replacement axleshafts that are 5 lug, as well as some 5 lug drums. Same way you would convert a 5 lug 10 bolt to 6 lug or vicy versy. Still not cheap, but at least easier than finding the 454 SS rear for sale near you.

Or, fix the 10 bolt. It lasted how long and how many miles the first time? What exactly failed? If it was a shaft get some alloy shafts, they're pretty cheap. if it was the Gov Lock keep in mind the G-80 is a known IED for a 10 bolt (Internal Exploding Device). If it was carrier related look into a full case LSD maybe.

Rene

 

[sweetk30]

watch out for the 88-up axles. there is a width diffrence i have heard of from 2wd to 4wd axles in the rear. so if you go replacement shafts then measure what ya got first.

 

[eagle mark]

Find a 6 lug 14sf and get some replacement axleshafts that are 5 lug, as well as some 5 lug drums. Same way you would convert a 5 lug 10 bolt to 6 lug or vicy versy. Still not cheap, but at least easier than finding the 454 SS rear for sale near you.Rene

What vehicles would this six lug SF axle be located in?

 

[tRustyK5]

The 6 lug SF 14 was in the 90's for sure, light duty 3/4 tons got em. If Brett says there was a difference in width between the 5 and 6 lug versions then I'm sure there is.

Why not swap the whole thing to one ton stuff and run 8 lug? The front seems like it'd be easy enough to swap, and a 14 bolt rear swap is cake for sure. Then you also get much bigger brakes which is good for a tow rig.

Rene

 

[4X4HIGH]

Yep, if it were me I would install a 14ff and convert the front to 8 lug stuff and buy new wheels and be ALOT stronger than it currently is.

I did this with an old 2wd 70 chevy truck I once owned but I installed a D70 rear since it was free and a brand new pull out.

 

[thorguy57]

Ok I got some information for you. You can get a 12 bolt out of a 73-78 2wd jimmy or blazer. It is 5 lug and has a 8 7/8" ring gear and 30 spline axles. If you find a 4 wheel drive blazer or jimmy 73-81 they also might have a 12 bolt but the axles are 6 lug. You should be able to buy new axles from a 2 wheel drive and throw them in the housing. They are both 30 spline. The only difference is the one on the 2wd model is 1/32" longer. Check out some parts diagrams and verify. Hope this helps.

 

[eagle mark]

Well it's all good information but I still don't know which way to go. I guess when I find a deal on the axle it will decide.

What has to be done to convert to eight lug front? I'm guessing all the parts from a 2wd pick up...​

 

[tRustyK5]

I have a C30 here with the front clip off so the entire front suspension is easy to look at and stuff. I would think you could swap the spindles out and be good. I also have a C10 pick-up here...

If you want I can have a look and see if there is anything really different.

Rene

 

[thorguy57]

I don't think the spindles will just swap over. I think the ball joints will be a different size. You might be able to get some wheel adapters made. Everything on the one ton is going to bigger including tie rod ends, ball joints, probably pitman arm. It would take a little bit of work and money to convert it all over.

 

[tRustyK5]

I just went and compared my C10 to my C30, and it sure looks like it would just swap. The differences I see are sway bar size, and coil spring size. The A-arms look identical, and the tie rod location looks the same. I guess you'd have to have the balljoints for both in hand, but again I'm thinking even if the balljoint is beefier on the one ton it'll still rivet, or bolt to the A-arms no problem.

Rene

 

[eagle mark]

I do appreciate the effort and in the end it'd be cool to have it converted to eight lug for brakes if nothing else.

But I'm not going to make a project out of a daily driver! I like this 2wd just the way it is.

So I may rebuild the 10 bolt but more realistically look for a 14 bolt SF and convert to five lug!

Why? Because it's done more than fine for all I need for 7 years. It has towed it's entire life and well now has about 125k miles after I convert from metric... so although it needs a rebuild now, it should after 125K miles...

But I always look for upgrade opportunities at rebuild or part failure time. Pretty sure I have 3:73 gears in it now so finding a 14 bolt with the same or 4:10 should be easy. Then I will just go through that rear end and have it ready to bolt in.

I tow in drive but sometimes go to overdrive on long flat roads as long as the converter stays locked up. If I went to 4:10 gears it would probably stay locked most of the time... but then when I do have to downshift on hills etc... I'd be revving higher so maybe I'll just keep the 3:73 ratio since it has been fine

 

[Captainfab]

A 14 bolt in either SF or FF would be a nice upgrade, but a 12 bolt shouldn't be too hard to find in our area. Any 12 bolt truck rear from a '73-'81 2wd ('71 & '72's with leafs) would be a direct bolt in, and a little better that the 10 bolt. It's been a while since I've been out to Garwood, but they should have a couple out there, in their pile of diffs. Heck they might have a SF 14 bolt too. That might be less $$ than rebuilding the 10 bolt

 

[tRustyK5]

10 bolt and 12 bolt are about equal in strength, the 12 bolt's ring gear is slightly bigger at 8.875, but the 10 bolt has a larger pinion bearing.

Rene

 

[howdiy]

I just went and compared my C10 to my C30, and it sure looks like it would just swap. The differences I see are sway bar size, and coil spring size. The A-arms look identical, and the tie rod location looks the same. I guess you'd have to have the balljoints for both in hand, but again I'm thinking even if the balljoint is beefier on the one ton it'll still rivet, or bolt to the A-arms no problem.

Rene

The heavier dutier one has solid a arm bushings too right?


What about a ford 9"?

 

[diesel4me]

My '85 K-10 Burb had its rear axle replaced with an earlier 12 bolt version,it was a bolt in swap,I thought it was original at first,till I got the date codes off the axle tube,its a '78 one I think..going that route would be cheapest,but as Rene said,they are about the same strength in the end..

I think the 1 ton 2wd suspension will swap right onto a 1/2 ton 2wd frame,but the 1 ton ball joints are different,so are 3/4 ton ones,I know the spindles have larger tapered holes for the ball joint studs,and I'm pretty sure the O.D. of the ball joints differ also,so you'll need the entire front suspension --a frames at the least,the rest might be compatible..I've heard of guys using certain rotor and wheel bearing combos to swap on 8 lug rotors onto 1/2 ton 2wd spindles...