Doom86

i got this Blazer going to the junkyard ASAP and id like to know if the Blazers rear gear or posi will swap over to my 86 z28? Both are 10 bolts and the Blazer has a 3.73 gear, which im not to "set" on putting in my z28 right now (its 2.73). But if it will make switching the posi unit over any easier i'll do the switch.

Ive been "told" they are the same spline, so given this is true would i need to change, or adjust the pinion as well? I'll count the splines on both vehicles, before i put the gear in the z28.

Id like to get this changed as cheap as possible, im on a real tight budget right now, and will be for some time to come.

Any help would be great here, im attaching a photo of the S-10 Blazers rear for reference.

Doom86

sorry, heres the photo

86z/92rs

An 85 S-10 posi will fit into your camaro. You will need to get the pinion as well. I am looking at the picture, doesn't seem like a posi but then again could be the picture. How did you know it is a posi. Did it have the G80 code, You spin one wheel and both wheels spin in the same direction ? The code should be in the glove box.

SS-84

It will fit.
Grab the Ring, Pinion, and all shims.
the pick up an installation kit, replace the bearings andset up the 3.73's in your other housing.

Doom86

86z/92rs, its deffinately posi. i remeber last winter when it was stuck in the snow both tires were spinning. Actually all 4 were I was the lucky guy behind it rocking it back and forth. That is a posi unit for sure, its identical to a photo reference i have. I'll make 110% sure before i go screwing with it anymore, its simple to check the glove box.. Whats the RPO code for the gear?




SS-84, you make it sound so simple. if only it was
The 3.73's wont fit in my 2.73's carrier, that is why i was thinking it would be easiest to swap the whole unit over. So i cannot use the Blazer's bearings?

Whats in the install kit? Part number perhaps?

ede

it's a posi, you can tell a lot more by looking at what you have than any half assed codes or one wheel will spin and both won't and they go in oppisite directions

do a search on here and you ought to find all the info you need

Doom86

i've done to much searching, lost sleep for a good week over it.. (still searching though) lol.. got 4 hours last night for example. I knew NOTHING about rear-ends before. Ive searched the internet and thirdgen and Nearly all info or tutorials are based around complete rebuilds, with new equipment. If you got a link man im more then greatful for it.

im sure its a posi i was just trying to be nice about it

What i was hoping was that everything i needed for the swap was either on the blazer or the z28.. but im just "wishful thinking", right? Funds are extremely tight right now


to remove the posi/gear i have to take the breaks off and pull the axle(s) out of it, correct?

ede

brakes, unless disk, can stay in place. you do need to remove axles to remove carrier. i wouldn't reuse old bearings, but if they aren't hurt you could get by with them. you need new bolts, nut, cruch sleeve or spacer no matter what.

RB83L69

That is an Eaton Gov-Lock. It's sort of a posi, but not exactly.

You CANNOT put a 2 series gear set (2.73 for example) on a 3-series carrier (one equipped with a 3.73 for example).

The 3.73 gears, along with the 3 series carrier, will go right into your Z28. They're both 26 splines on the axles.

However, that Gov-Lock carrier is notoriously weak. Those have a well known tendency to grenade when used on pavement. They were intended for off-road use in traction-limited situations such as mud. They have earned the nickname "Grenade lock" from the S truck crowd because of being so fragile, even behind 6-cyl motors. They are not quite like a traditional "posi"; they act like an open carrier until the RPM difference between the axles exceeds about 100 RPM (that's what those little weights are, is a governor), and then they lock with a bang. That's when the parts start to fly out. In other words, no posi action occurs, until AFTER wheel spin has already started. I would recommend against using it behind a V8 with any kind of traction at all.

You would need a "gear install kit" to install gears; it consists of the bearings, shims, a new crush sleeve, new nut, ring gear bolts, and some other goodies. About $100.

86z/92rs

Thanks for clearing up RB83L69, that diff. somehow looked different but as ede state it's best to actually look at the unit rather than code by the code. But here are the gear codes anyways:
G80 = Locking Rear axle/Positraction
GU2 = 2.73
GU4 = 3.08
GU6 = 3.42
GT4 = 3.73
GT5 = 4.10
GS4 3.70
GT4 3.73
GT5 4.10
GT7 3.33
GT8 4.10
GU1 2.41
GU2 2.73
GU4 3.08
GU5 3.23
GU6 3.42
GV2 5.83
GV4 3.36
GV8 2.72
GW4 3.31
GW6 3.27
GW9 2.93

Doom86

many thanks you all. knowledge is infinite.


and thanks for the warning, RB83L69. Right now i have the cheapest tires you can get at Sears on it, they were on it when i bought it, so im not worried about to much grab. In January we are changing to Z rated so it may cause a problem then. Do you think the gov-lock will still improve off-the-line take off? is what is referred to as a "locking differential"?

I could have sworn i saw an adapter at Jegs to put series 3 gears on a series 2 carrier.

If they are both 26 spline then do i still need to change the pinion out?

RB83L69

Yes, you can get a spacer to do that (3 series gears on a 2 series carrier); but not the other way around. You can't put 2 series gears on a 3 series carrier, unless you can invent a spacer that makes thing thinner, instead of adding thickness. In which case, you'd be an instant billionaire no doubt.

The axle splines have nothing whatsoever to do with the pinion. If you change the ratio, you have to change the pinion, because it will have a different number of teeth and will be a different diameter (that being the definition of "ratio"); and since rings and pinions are matched sets, that means, you keep the R & P together out of each rear end.

That carrierr won't last long behind a V8, in spite of the occasional report you see here about "I've had one for x years, it still works". Those lucky folks are the exception to the ordinary. They rarely survive if used with enthusiasm on pavement. Since it allows tire spin BEFORE it does any locking action, it's near useless for off-the-line take-off; and if you try to use it that way, it turns into a bomb.

All in all, I'd suggest letting it go; and get something that's really right for the Camaro. Maybe keep the 3.73 gears, but throw that garbage carrier away.

Doom86

Im going to take your advice, RB83L69. We have a freshly rebuilt 350 out of a 71 3/4 ton chevy truck waiting to drop into my z28 so it would be even more of a bomb then, id emagine. I would hate to loose the whole rear for the sake of expeirmenting..

Reading after you first mentioned it being a "gov lock" i found that GM started using them in 72, which means the engine doner truck COULD be a posi doner, couldnt it? (given its posi diferential). Whats the determining factor? axle diameter? rearend bolt patern?

RB83L69

Determining factor for interchange = rear end model; usually expressed by the ring gear diameter.

A 71 ¾-ton truck would have had at least a 12-bolt; or a 14-bolt if it's a 8-lug IIRC.

The 7½" rear was introduced in 77. So it's impossible that any parts out of any rear earlier than that, would interchange (except maybe axle bearings).

Doom86

Your just full of "bad news" today, RB83L69.. No worries though, im not "Shooting the messenger".. Many thanks bro.

zman1969

iTrader: (9)

dont forget the nickname of GOV-POP they do have a tendency to break when shocked hard save yourself the greif get a real posi or a zexel-torsen and 28 spline axles out of a 89-92 with disc or drum respectfully thats what i did for my 87 :lala:

forums_suck

Theres lots of the 2 series eaton posi's on ebay and they go cheap and there fairly strong

Ive seen those gov locs sell for 100 on ebay ya might want to put it on there?

Doom86

I think im just going to get a rear end from a junkyard and rebuild it when funds allow it. You can get them for 50$ around here, if you pull it.

Im going to pull this gear out and give it to a friend who wanted one for his 85 IROC.

Thanks for all you help everyone.