Hey guys I found a 9 bolt borg warner on craigslist and have never heard of them. Are they just as good as a 12 bolt or 9 inch? The guy says its disc brakes posi 2.77 gears. Any information would be greatly appreciated. Oh and he's asking $200 for it.

 

Ok so I've read this thread thoroughly and now know more. Sorry for posting a new thread before finding this very informative thread. Now my only question is are they worth the $200 this guy is asking?

https://www.thirdgen.org/forums/faq-...now-about.html

 

Depends, I think I paid 150 for mine but it has 3.27's and a posi (in addition to the disc brakes). It's been a good rear end, but unless you want 2.77 gears I'd pass on it. Because you'd have to swap the carrier in order to put 3.27's, .45's, or .73's in it and at that point you are putting more money into it than you paid for it (gears and parts for 9-bolts are expensive).

 

Thank You. I will continue to look for a 3 series or 12 bolt, 9 inch etc. Bc I don't want to be stuck at 2.77 gears

 

Anytime, good hunting!!!

 

Hey, random but this guy has a 3.27 9-bolt for 100 bucks.

https://www.thirdgen.org/forums/engi...arts-sale.html

 

Only if it has the PBR 11.655 rotors and aluminum calipers. Then it might be worth it just for the brake upgrade.

 

Yeah it may be considering mine is the stock 86 10 bolt 2.73 gears open rear axle with drums.

PS. thanks for the photo I'll use it to compare when and if I go look at it (2Hr. drive sucks)

 

I posted a few questions for that thread no the waiting game to see if they answer.

 

Im talking with the guy from that thread now..... He asked what all I would need to convert from a 2 series to the 3 series. Do you know what all I would need?

 

9-bolt parts and your 10-bolt are NOT interchangeable.....Your best bet is a complete rear assembly.

 

I didn't mean for my 10 bolt. I was talking about if/ when I purchase the 9 bolt that I had mentioned earlier in conversation.

 

I've never done it, so this is just from a google search- but basically you gotta swap all the guts from the 3 series (inside the differential) into the 2 series. That is your carrier, and gears, and maybe some other things. But idk if it requires any special setup or anything, most people recommend just buying a 3 series complete and rebuilding (if needed).

I'm sure somewhere on here somebody has done it and can weigh in.

 

I did a little research with 9bolt.com and the administrator there stated you only need the carrier, ring and pinion gears.

 

Gotcha, good luck with what you decide to do!!

 

DJP the guy replied and stated:
rotors-10.5"
calipers-sgl.piston steel w/e-brake

But its still an upgrade from drums.... How hard is it to convert the ebrake?

 

I would not buy it, those rear brakes are crap. Any rear with 10.5 rotors and iron calipers I would stay away from. That $200 is not a buy now in my opinion.

 

This is the exact reason I came to my thirdgen family to figure out. Thanks for all of the help. I am going to pass on it and keep looking for a good posi rear for my build.

 

9-bolts are a little better than the 10-bolt if and ONLY if they already have the good stuff on them and the posi carrier is healthy. THere are ways to check that. Mainly you want:

1. The good brakes (only 9-bolts from 1989 have these)
2. 3-series carrier
3. Healthy posi

Because parts for these are so stupid expensive that any invesment in any area here will cost you more than the diff is worth. I paid $200 for new gears, the only new gear ratio available for these, and that's almost too much to invest by itself. But luckily I have the good brakes and a healthy posi carrier, otherwise it would never be worth it.

I'd get a 10-bolt from 89+ (will have the same good brakes) and the 28 spline axles so you can swap in a Torsen posi to replace the likely worn out auburn posi and you should be set until you make enough power to blow it up. With rear ends, I know it's annoying, but it's really worth it to get something that's right the first time. These rear ends are worth their used value, so you can get them for cheap. Paying for any part of these things new or aftermarket costs a relative fortune, even for 10-bolts, compared to what you can get them for if you buy them all together in one package to begin with.

I have a Torsen carrier for a 10-bolt in the event I blow up my 9-bolt.

 

So what is your opinion on the bolt drum vs 9 bolt iron caliper? Which is the lesser of 2 evils?