10bolt posi questions

[SickSilverado]

I have a 8.5 10bolt in my 1982 Silverado. I'd say it weighs between 3400 and 3500 without me. I'm only making around 400hp, but I plan on spraying it soon. I have a 3500 stall in a TH350 and 4.56 gears with 28X10.5 slicks. The truck is track only and sees maybe 9 passes a year.
My questions are about posi units for the 10bolt. I'm on a low budget aswell as a very short timeline. A friend has offered me a couple of GM clutch-style posi units(not the Gov-Loc). I was wondering if the GM clutch posi will hold up to some hard launches for a few passes. I've asked this question several times and most say buy a good aftermarket posi or use a mini spool. But I don't have the money for a nice posi and I don't want the added stress of a mini spool. A full spool is an expensive setup since I'd have to buy axles, c-clip elims, and new bearings(I think). I have a 12bolt sitting around, but I'm waiting to have it built right, when I have the money.
What I really want to know is if I can get away with a clutch style posi for 9 passes. Will it let me hook good? Can I set it up to be more aggressive?

[Scott @ DLS]

Post up a picture of the GM units you have. IMO a new style Eaton 4 spring would be fine for what you are doing. They have a larger journal so a conversion bearing will be needed to fit your older style housing. Your axle spline is 28 so I would hope you would upgrade it to a 30 spline and possibly a set of aftermarket axles. Besides that just don't launch it off a trans brake, c-clips just love to break and thats when the axle comes flying out.

[SickSilverado]

I don't have pictures of the actual units we have, but here are two on ebay that are just like the ones my friend offered me.
http://cgi.ebay.com/ebaymotors/8-5-gm-posi_W0QQcmdZViewItemQQcategoryZ33731QQihZ010QQite mZ200288251963QQrdZ1QQsspagenameZWDVW

http://cgi.ebay.com/ebaymotors/CHEVY-8-5-GM-10-bolt-POSI-UNIT-3-SERIES-LSD-car-truck_W0QQcmdZViewItemQQcategoryZ33731QQihZ012QQit emZ220330120515QQrdZ1QQsspagenameZWDVW

Like I said, my budget was blown on other stuff just to get the truck running. My launches aren't hard at all. I don't have a trans brake either. That 12bolt is going to get thrown in around the summer time. I just need a solution for this 10bolt for short while.

[Scott @ DLS]

I don't have pictures of the actual units we have, but here are two on ebay that are just like the ones my friend offered me.
http://cgi.ebay.com/ebaymotors/8-5-gm-posi_W0QQcmdZViewItemQQcategoryZ33731QQihZ010QQite mZ200288251963QQrdZ1QQsspagenameZWDVW

http://cgi.ebay.com/ebaymotors/CHEVY-8-5-GM-10-bolt-POSI-UNIT-3-SERIES-LSD-car-truck_W0QQcmdZViewItemQQcategoryZ33731QQihZ012QQit emZ220330120515QQrdZ1QQsspagenameZWDVW

Like I said, my budget was blown on other stuff just to get the truck running. My launches aren't hard at all. I don't have a trans brake either. That 12bolt is going to get thrown in around the summer time. I just need a solution for this 10bolt for short while.


The first one is an old GM S spring posi that wont last long, not enough preload on the clutch packs. The second one is an Auburn and depending on the usage it would be a good unit. You can check the Auburn by feeling the amount of slop the pinion gears are in relationship to the axle gears. The looser they are the, the more wear the unit has on it.

[PONYEATER]

if you are looking at having something last 8-9 passes I would throw the S-spring unit in with NO posi additive. They should hold for a few passes.

[SickSilverado]

Is there any way to increase the tension on the springs with the S spring posi? It only has to last a few passes, but it also has to spin both tires. My G80 embarrassed me a few times with some 1 wheel burnouts at the track.

[B-man]

Just weld it already!

[SickSilverado]

LOL. The lincoln locker. I really don't want to go that route. I'd like to either give this rearend to my brother's truck or sell it when I put in my 12bolt.

[1952_chevy_panel]

Having the same problems with our mammoth.

http://img2.putfile.com/main/10/28619531392.jpg

468 BBC, TH400, 8.5 10 bolt. We ran the rear end the way we got it for 3 years, probably had 40+ burnouts or more on the S spring type carrier. Had a local shop rebuild it after it started to slip, and it wouldn't lock up after the rebuild either. Local shop sent us home with a "lincoln locker" and it's now broke. My dad and I are in the same boat as you, lost on what to do next. We'd be happy if we were to get a S spring carrier to hold the way it originally did, like in the picture above.

[PONYEATER]

Best way long term is to open the wallet.

[RCJ]

When I was dirt track racing wielding the teeth in the gears worked better than wielding the gears to the carrier.I have a govlock (why are they called that anyway) in my 71 camaro it might spin both tires or it might not when doing a burnout but it always works when the light turns green.It will cost about $650 to upgrade your 10bolt to a spool,bigger axles and c-clip eliminators.I'm trying to decide if a 9'' would be a better way to go.

[SickSilverado]

See, I don't want to spend too much on this 10bolt. I have a 12bolt I'm going to build up when my business picks up. I HAVE to make it to this event, but I can't have my Govlock making me look stupid.
But I may have another option. My brother may be getting a truck soon with a 12bolt in it setup the way I want it, so we might trade. If not, I may just do the lincoln locker and pray for the best.

I can't remembe why they call it a gov-lock.