Rear end woes/questions
 

http://67-72chevytrucks.com/vboard/s...d.php?t=474536

A while back I damaged my rear end, theres pics & details in that thread.. What I've learned since is that there was half of a gear floating around in my rear diff from the last time it was worked on (the previous owner) so it was just a matter of time before it broke some other things, maybe it was on the magnet all along & finally came loose, who knows.. I don't know how someone could make such a dumb mistake, but its done now.

I'm going to rebuild my rear end with new parts since I wasn't able to track down parts to do an easy swap. I was looking in LMC (just to see what all I need) & looking at axle shafts its saying that any 10 bolt with 8.5" ring gear will have 28 spline axle shafts, but when I took my axle shafts out, they were 30 spline. I'm really unsure as to what that means, & I want to make sure I order all the right parts.. I'm not going to replace the axle shafts, but I want to be sure when I get my side gears that they will be 30 spline. Can anybody provide me with some insight here?

Re: Rear end woes/questions
 

In 1988 they changed the 10 bolts to 30 spline so maybe they threw a few in for 87 ???? or maybe somewhere along the line somebody has put a newer carrier in your older 10 bolt . I would take the number off the carrier and do a search

Re: Rear end woes/questions
 

The best advice I can give you is to re-read the original thread, especially the parts were the guys say not to try it yourself. It will end up costing you more in the long run. This is just not a job for a first timer. It takes some very specialized tools and a lot of patience. It is just not worth the effort for something that most guys only ever need to do once.

Pay the man, and get a warranty, and use synthetic lube.

Re: Rear end woes/questions
 

No thanks, there aren't many places I could get this done around for a reasonable price. I have all the tools necessary & help who has rebuilt differentials, trannys, engines & worked with metal everyday for the last 35 years.

Re: Rear end woes/questions
 

You can get a newer ring & pinion set on a carrier with 30-spline spider gears pretty cheap at nearly any wrecking yard. The 88-up 1/2-ton Chevy & GMC trucks, Suburbans & Tahoes still use the same 8-1/2" 10-bolt guts that are in your rear axle.

My local yard has two sets right now with 3.73 gears on a posi carrier for $150. You should be able to find some locally for about the same.

You could also just go to a pull it yourself wrecking yard and grab the whole rear end out of an 88-up truck for under $100 and put the square body spring perches from your rear end onto it. They are just a little wider than the square body rear end and push the rear wheels outward a little to even out the inset rear wheels the square body trucks have. This way the front & rear wheels have closer to the same track width & wheel well location. You will probably not find a low mileage 88-up rear end in a pull it yourself wrecking yard so it will probably need new bearings at the least.

With the kind of damage you have the bearings are all compromised and need replaced any way so rebuilding your rear end or getting a newer one to rebuild will cost about the same money once you buy the repair parts yours needs.

Setting your pinion depth to get the right wear pattern, setting pinion bearing preload and setting ring gear backlash are not things to be taken lightly. Just the slightest error can ruin parts in a hurry and cost you way more than what a rear end shop will charge you to set up the gears properly the first time. If your friend hasn't specifically rebuilt GM rear axles before you are better off spending the money to have a shop do the setup for you. If you bring them the rear end and parts in hand most shops will only charge you $100 to $150 to install the bearings and set the gears up properly. Well worth the money.

Re: Rear end woes/questions
 

Where I'm from, there really is no abundance of auto wreckers.. My choices are starting to overwhelming me.. I can get matching 3/4 ton axles for $1500 off of a newer dodge or ford, I can go with a posi unit in my current rear, I can have someone rebuild the 3.42 open diff thats in her now, for $1k-1.2k (probably $1500 or so with a posi??). Or I can go to the wreckers & buy a rear end with no history & no idea what to expect as to how long it may last me, but even that would cost me upwards of $500-$600 here, not a measly $100 or so like down south, then still have to fix it up before its ready to go.. I'm just sick of not having this thing on the road, it was fine before it was my only vehicle & DD but I lost my job & my old Nissan DD failed to pass the etest, so I need this thing up & running asap to get back on track

Re: Rear end woes/questions
 

Sounds like you should look for a used square body rear end that will bolt in.

How far north of the border are you? What is the nearest US town to you?

Re: Rear end woes/questions
 

I found a shop thats going to rebuild it for a decent price.. Now all I have to decide is whether to stay with the open diff, or get a posi unit for a little extra.. Any insight?

Re: Rear end woes/questions
 

Uh, OK....I'm lost? :waah:

Re: Rear end woes/questions
 

I put posi into my old Blazer that had an open carrier. With posi I didn't have to put it in 4x4 as often. Saves a little gas and wear & tear.

It is worth the money to do it now while it is apart and being rebuilt.

Re: Rear end woes/questions
 

If you're unemployed, I think I would find the least expensive route so you can have a vehicle to drive. Having a posi would be the last thing on my mind.
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Re: Rear end woes/questions
 

Lol understandable.. I have the money though which I wasn't thinking I would, & thats why I hoping to fix everything myself. I still have a side income & I got bonuses from the last 2 years when I left my job. Tuesday I'm going to go in & discuss what exactly to put in there.

Re: Rear end woes/questions
 

Came to my senses, my trucks in the shop now! Its getting a new auburn posi, new 3.42 ring & pinion gears & all new bearings & seals. Should be ready tuesday or wednesday :)

Re: Rear end woes/questions
 

Good to hear it is getting done right. Hope everything goes well.