Last night i launched my car and the rear went boom. It is an 89 RS with a rebuilt 87 rearend with an auburn posi. I tore it apart and found that the gears were fine it just blew the spiders and internal stuff in the carrier. its a 3.73

I found a slightly used rear on craigslist for 300. Its got richmond gears and a stock carrier. its from a 91 Z28. the guy says its posi and it was all rebuilt about 1000 miles and but its been setting for 2 years. is this a good thing in your opinion? i have about 350 hp and running mid 12s with slicks

or my other option is spend more money on a detroit locker alot more and know what i have.

My question is that when i look on summit they dont say its for my car so i searched 10 bolt and i have 26 spline axles so when i clicked on that the only axle model that came up was 7.5in and i thought mine was a 7.625 being an 87 or if i click on 7.625in only 28 spline axles carriers come up.

what do i do about that or does in not matter the size?

 

Spline count: upgrading to 28 is worth it. Until you do, the 26-spline axles are the weakest link, and dangerous without c-clip eliminators. Once you have 28-spline axles, the c-clips are still a worry, but even with stock '91-'92 28-spline axles, the weakest link becomes the ring & pinion set. If the '91 rear has the ratio you want, then install that. '87 Should be 7.625" 26-spline, but you'd buy the Detroit Locker for 7.500" 26-spline, because the ring gear bolt pattern is the same, as are the bearing journals.

 

7.5 or 7.625 will both use the same gears, and will interchange in different housings. The only difference in the two is the space where the spider gears go, the 7.625 is slightly larger internally.

The rear is on borrowed time reguardless what you do to it, especially with slicks. The craigslist rear is worth looking at, but have the guy pull the cover so you can inspect the wear patern on the gears and see if it have a posi and not a open or a gernade lock in it.

You should think about a new rear, a bolt in 12 bolt or 9"

 

Ok thanks now i know what i can do about a new carrier. this is it. http://www.summitracing.com/parts/DTL-162C58A/
The guy selling the rear is over 2 hours away and that is what sucks about it. he says its good and it has clutches in it so im sure its a posi. im just torn on what to do. spend 300 and risk a junk one or 700 by the time its all rebuilt and have all new

 

Oh and one more thing i forgot to metion is that i was looking at an instulation kit and all i can find for my rear is this http://www.summitracing.com/parts/BCA-RA320MK/ but is says it is for 27 spline. does that even matter when it comes to an instulation kit? there is not even a option on a 26 spline.

 

IIRC, the pinion yoke is 27-spline.

 

Different from the axles, which are either 26 or 28.

Your rear would use the 308TK installation kit in the Ratech brand. That'll get you all the bearings, all the seals, new ring gear bolts, shim packs, and crush sleeve which I suggest NOT using, use a 4111 solid spacer instead.

 

Well i decied to get an eaton carrier http://www.summitracing.com/parts/ETN-19663-010/ and the pinion spacer 4111. i got a bearing and spacer kit from advance. and it came with the ring gear bolts, pinion nut and seal, and some paint to check smear pattern. thanks for your guys help. ill post pic of the build. its a 3.73 ratio by the way.

 

well its done. the carrier i ordered didnt work and i thought it was because i oreded an old 7.5 in or somthing. i found that the ring gear was mouned closere to center then my old carrier and it was hitting the pinion too hard. so i drove to summit, about 3 hours and returned that carrier and brought my old carrier with me so i could compair side by side and get the right one. tried to get another eaton carrier but it was the same way. after talking to guys there we found out that who ever built ther rear before me had a series 2 carrier and got a 3.73 ring and pionion set that actually fit on a 2 series and i orded the 3 series.

if i didnt go to summit i think would have been returning alot of carriers before i figured it out.

I ended up with a detroit true trac, it was the only one i could get that was a series 2 carrier. if i didnt do that i would be buying gears also. i got it in tonight and took it for a drive. it is making a whinning noise. it gets worse on turns. i hope it is just breaking in. i have the pinion preload set to the spec i had and i had about .006 back lash. and all the bearings are new. i have read that some gears are not as good quality and whine? mine were whinning before also so maybe that could be my problem?