90Camaro5speed

I have a 1990 camaro rs 5 speed with the 3.08 open diff. If I wanted to make it posi would I need to swap my rear end or can I put in a different diff to make it posi? I don't want to lock my diff tho.

cosmick

To do it yourself, the easiest way is to just swap the entire rear axle assembly for one that already has a traction differential of some sort, and probably has a more aggressive gear ratio as well. If you just want to install a traction differential in the axle you have, and keep the 3.08:1 gears you have, then you will need a magnetic-base dial indicator for checking backlash.
Backlash is adjusted by the carrier shims, and as long as you have some, you won't lock up anything in a bad way. Separate from that, locking differentials aren't necessarily bad, either, especially for dragstrip use. But these axles aren't inherently strong for that sort of thing.
The low-cost way to do this is to get a used Auburn ( which BigGearHead will bash ) from a '93-'02 Z28 with the auto and the standard 2.73:1 gears. '93-'97 used a different Auburn with 3.23:1 & 3.42:1 gears, that one can't be used with your 3.08:1 gears. Likewise the Zexel Torsen from '98-'02.
The best way to do this is to order a new differential. But you have one more option, you can get a "lunchbox" locker that just replaces your spider gears, around $350, then you don't even have to worry about the backlash. This is tied for the easiest way, but you may not love how it drives afterward. Powertrax makes the LockRight, they have another one that costs more but drives nicer, and Randy's sells the Spartan, which may be a Yukon product. That's probably slightly cheaper than the LockRight, and just as good otherwise. But you may find a LockRight from Summit as cheap as the Spartan.

JamesC

iTrader: (5)

Welcome to TGO, 90Camaro.

Check the 10-Bolt FAQ sticky at the top of the page for info that may prove useful.

JamesC

big gear head

Your 3.08 gear makes this a little more difficult because you need a 2 series differential. As far as I know all of the after market limited slip differentials are 3 series, which would work fine if you had a 3.23 to 4.11 gear. Your 3.08 will require a used factory installed 2 series Auburn or Torsen differential. With your car being a '90 it will have the larger 28 spline axles, which means that you can use the Torsen. If you had the older '82 to '89 then you would have 26 spline axles and the Torsen wouldn't work without an axle swap. So remember this when you are looking for a differential and remember that you will need one for 28 spline axles.

As for the Auburn, they wear out quicker than most other limited slip differentials. The big problem with this is that they can not be rebuilt. When they wear out they are scrap metal. Installing a used Auburn is usually not a good idea.

I found this used Torsen. These are not too hard to find. I couldn't find anything new in a 2 series with 28 splines. http://www.ebay.com/itm/181935549582?item=181935549582&rmvSB=true

cosmick

New, not used, Auburn 542047 $ 513 at Summit. 28-spline, 2-series, "Pro" version, 7.625" or the regular version is pn 542041, $455.
You can send them back for a factory rebuild, they typically last well over 100,000 miles of daily street use, but you have to change the lube more often, because as they wear they contaminate the lube.
I'm fairly certain the above listing is wrong, there never was a 2-series Zexel for the 7.625" 28-spline, only a 3-series. If you buy it, don't be surprised if it doesn't fit.
The LockRight is pn 1931, $412, the smoother version is called the NoSlip, at $480. Seems the Spartan isn't offered for this.

sofakingdom

iTrader: (1)

Auburn will only honor the "rebuild" thing for a very few years; NOWHERE NEAR long enough to accumulate the miles in question.

It's an empty worthless LIE meant to sucker you into believing you're actually getting something "rebuildable". In fact, if you send them a failed unit within the warr period, they just send you another; they can't "rebuild" it, any more than anybody else can, by any means other than swapping it out.

GARBAGE.

Don't let em jyp you outta your hard-earned cash. Get something else. NOT anything 2 series.

90Camaro5speed

[QUOTE=cosmick;5983636]New, not used, Auburn 542047 $ 513 at Summit. 28-spline, 2-series, "Pro" version, 7.625" or the regular version is pn 542041, $455.
You can send them back for a factory rebuild, they typically last well over 100,000 miles of daily street use, but you have to change the lube more often, because as they wear they contaminate the lube.
I'm fairly certain the above listing is wrong, there never was a 2-series Zexel for the 7.625" 28-spline, only a 3-series. If you buy it, don't be surprised if it doesn't fit.
The LockRight is pn 1931, $412, the smoother version is called the NoSlip, at $480. Seems the Spartan isn't offered for this.[/QUO

So if I were to buy the noslip would that be all I need? Just simploly install that or is there more to it? And also if I were to get a whole new rear end what would you recommend? 9 bolt? 10 bolt? And what gear ratio? Thank you for the help. Much appreciated

big gear head

I wouldn't use the No Slip. The Lock Right works better. To install one of these all you need to do is remove the 4 gears inside the differential and put these parts in. You don't have to reset backlash or bearing preload. You don't even remove the differential from the rear end. You need to know that these locker kits pop and jerk a little, so if you want something that is going to be completely smooth then you might not like these.

cosmick

If you're happy with your 3.08:1 gearing, and really like it, then you really wouldn't notice the change to 3.23:1 gears, but that small change would give you way more choices of differentials. It would also add to the cost.\
Using a '98-'02 axle is a direct bolt-in, except it's about 1.5"-2" wider per side, I forget the exact amount, but it would require a change of rear wheels, or spacers up front if you change all 4 wheels.
I'm not convinced the 7.75" 9-bolt is really any stronger, but you can get one with 3.27:1 gears.
As for rebuilding an Auburn, it has been done, there's even a video on YouTube. Not seeing it right now, but I've watched it before.

90Camaro5speed

So my rear end right now is the 10bolt 3.08. I found a 9 bolt 3.27 with posi which I'm interested in because I specially want posi. But I know in the future I plan of possibly doing an engine swap. Is there 3.27 a good choice for this? Or what are the best gearing for when I upgrade to more power?

sofakingdom

iTrader: (1)

"Best gearing" is related to engine RPMs, car weight, transmission choice, converter, intended purpose, driver/owner preference, and a few other things.

For a TPI motor, 3.2x is about ideal; the motor's power curve is at such a low RPM that gearing too high forces the RPMs up past where the motor can make any power at all. For a TBI motor, once you get rid of some of the restrictions (exhaust, heads, cam, & tuning, in more or less that order) you have a bit more freedom.

Night rider327

iTrader: (13)

I have had the LockRight locker for years. Great unit. When I moved to a ford 9", I gave my dad my locker and he's used it now for 5 years or so. I had it for 5 years before that.

Install is SIMPLE. Takes about 2 hours at most in your driveway. Jack up car, put stands under it. Remove cover, remove cross shaft bolt and crossshaft, slide axle out a tad, like 1/2" or so, take the 4 small gears out (axle/side/spider gears)

Put the locker in place of those gears, put the springs in the locker, put crossshaft and bolt back in, put on cover and fill with gear oil.

Here is a few pictures

sofakingdom

iTrader: (1)

I suppose it might be possible to buy a new one, take it apart, and put the parts in an old one; bearing in mind, that the "old" one CANNOT be already wore out, because it's the carrier case itself that wears.

Still, considering that Auburn doesn't sell parts, anything that could be called a "rebuild" is out of the reach of most people.

All of which is why I REFUSE to do business with that company. Kinda like Apple... always looking for ways to make you their stooge and pry your wallet open repeatedly as often as possible while giving you less than the ad copy promises.

8t2 z-chev

regarding reply #10,be aware that 9 bolts almost always have a badly worn posi and almost always disc brake(I would say always disc,but drum 9 bolts have been reported,,,) pre-89 rear disc calipers are klutz and often ineffective.. A Zexel torsen posi carrier from a '98-02 4th will fit in your '90 rear and these have a 3.42 gearset.

90Camaro5speed

I also interested in a 4th gen rear end but everyone says that it makes the rear a little wider and iv seen pictures and I'm not to fond of how it looks. People say you need to get new wheels but I'm trying to keep the same ones

8t2 z-chev

you can just take the posi carrier and gearset from the 4th gen rear and install in your '90 rear-your '90 axles will work with the 4th gen carrier.For best results,condition of all parts should be checked and bearing preloads,clearances etc.set. '

90Camaro5speed

I can do it with the open rear end I have now? Or are you saying if I get buy the third gen posi rear end ibwas talking about and outing better gearing in it?

big gear head

You can get a 4th gen differential and put it in your 3rd gen rear end because your '92 will have 28 spline axles like the 4th gen. The differential will have to be the correct series for the gear ratio that you are using, or you will have to use the 4th gen gears too.