ddeennis

Just bought a used 1992 open (single spinner) rear end , it came out of a camaro has
has the mark on the ring gear of 7 5/8" ( 7.625") and has the 2.73 gears
in it.

What I want to do is purchase a posi center section off ebay and replace the open rear end center section.

Looking on ebay I'm finding many 7.5" posi units in my price range
just wondering if these will bolt in? and I can still use my current 2.73 gears.

the 7.5" units I'm looking at on ebay are 2000 modle camaro posi units, auburn.

I'm staying away from the "locker" style.

Just need a little help what will bolt in with least amount of problems, I
did read the sticky on 10 bolts I'm not clear on if this will bolt in AND use my current gears.

ddeennis

http://www.ebay.com/itm/Camaro-auburn-posi-Unit-7-5-28-Spline-10-Bolt-/301041189588?pt=Motors_Car_Truck_Parts_Accessories&hash=item46177402d4&vxp=mtr#ht_186wt_880

looking at this one to use in the 1992 rear end and just bolt my 2.73 ring gear on it.
put the rear back together. will this work? I might need a ring spacer for this one right?
since it had 3.73 gears.

ddeennis

http://www.ebay.com/itm/98-02-Camaro-7-5-2-73-Differential-Ring-Pinion-POSI-10-bolt-28-spline-Auburn-/310805997987?pt=Motors_Car_Truck_Parts_Accessories&hash=item485d7b29a3&vxp=mtr#ht_614wt_642


Also looking at this one, take the ring gear off, bolt my 1992 ring gear on and set
it into my 1992 rear end and of course check tooth contact and be done. Would this work?

DJP87Z28

You have 2-series gears (2:73) and that LSD may be a 3-series, if the seller is correct it had 3:73 gears on it. So it will not work for you unless you switch to 3-series gears. Info: 7.5 & 7.625 use the same parts.

ddeennis

http://www.ebay.com/itm/98-02-Camaro-7-5-2-73-Differential-Ring-Pinion-POSI-10-bolt-28-spline-Auburn-/310762297463?pt=Motors_Car_Truck_Parts_Accessories&hash=item485ae05877&vxp=mtr#ht_614wt_642


another one on ebay, pop the ring gear off and slide mine on and bolt in and go?

ddeennis

Thank you for the reply, where does the difference come into play then between 7.5 and the 7.625?

So I can bolt in any "7.5" center section into my housing as long as it
is 28 spline and 2 series and my ring gear will bolt up fine?

I just hate to buy a "7.5" center section
and something don't line up right. I would rather ask a ton of questions then buy something that just won't work.

ddeennis

How about this, can I purchase this posi unit below and bolt it into my 1992 rear end
and run my 2.73 ring gear on it? Everything be fine? If so then I'll get this one and get it on the way.



http://www.ebay.com/itm/98-02-Camaro-7-5-2-73-Differential-Ring-Pinion-POSI-10-bolt-28-spline-Auburn-/310805997987?pt=Motors_Car_Truck_Parts_Accessories&hash=item485d7b29a3&vxp=mtr#ht_614wt_642

sofakingdom

iTrader: (1)

Yup, slap right in there.

Only difference between 7.5" and 7.625" is the OD of the ring. Everything else is the same. Most of the time people don't even bother to make a distinction.

big gear head

There is no such thing as "just bolt it in" when talking about ring & pinion gears. You will not have to set the pinion depth because you are not removing the pinion, but you will have to set the backlash and bearing preload. I highly recommend checking the backlash BEFORE you remove the old differential so you will know where to set it when you install the new differential. Read this before you start. http://www.nastyz28.com/forum/showthread.php?t=19773

I would NEVER recommend buying a used Auburn. They are junk when new, and used they are just scrap metal. When they wear out they will only spin one wheel and they CAN NOT be rebuilt. Take my advice and PASS on the used Auburn. Also don't be tricked into buying a Governor Lock.

I would recommend getting a used Torsen from a '98 to '02 Camaro or Firebird. I don't know if they were available in a 2 series. You MUST use a 2 series with your 2.73 gears and you also must use a 28 spline differential.

ddeennis

I bought the unit I had posted in #7 , they accepted my offer of
135 bucks shipped to my house, so it looks like it
should be good, fairly low miles,fairly newer unit.

Man I know I said slap in and go, I just didn't want to go thru the spill
of yes I know what I'm doing setting up a rear end, my experience is the
8.5" 10 bolts, this smaller unit just wanted to make sure I would be ok
with the parts I got. I'll set up right.

If I go with everyone advice, I would never own a posi trac rear end, I've
always been aware of the gov. style, but many folks have them and they are still on the road working and providing two black marks.

if I go with auburn advise above, that leaves me with one choice, but there are many auburn units working just fine on the road.

Look this is a low hp car the auburn unit should be just fine, the
car might do 13's, so whats the beef?

I have
the aussie 9 bolt, ya they wear out (posi) not cheap to repair
but they can be fixed. this ( different rear housing and ebay posi)was a cheap solution, then trying to make an 9 bolt open aussie rear end a posi.

I looked at a diagram for auburn posi it's kinda like the aussie cone style
if needed i could take a little off the bottom off the cone and give it more room before it's bottomed out.


thanks for all the posts, it helped to make sure I can swap what I needed to swap, I just never messed with the 7.5 rear ends, so I never learned
what can cross over and what years and what not. thanks again

sofakingdom

iTrader: (1)

The Auburn can't be "rebuilt"; there's no parts available for it. Call Auburn yourself if you don't believe me, they'll talk to you on the phone and tell you the same thing.

If (big if) it works, then sure, it's better than an open, or a Gov-Lock; just, don't expect too much. There's other things that go wrong with them too, besides just the clutches wearing out. They're just not a very well-designed or well-built unit.

There's nothing really any different about working on the 7.5", compared to the 8.5"; if you're familiar with those, then what you know will transfer over pretty well. Like the 8½", generally you can re-use the same shim thickness that came in the housing you're putting it into; not necessarily the same shims, but the same thickness, since the variable part (the one that creates the need for select-fit shims in the first place) is the housing not the moving parts, but the factory cast-iron shims are often worn substantially and can't be re-used. Spec for the backlash is something like .008" - .012", and the preload should be around .010" - .015"; pretty similar to the 8½".

ddeennis

Oh I beleive ya, I looked around, even thou there is no rebuild kits, you can cut down the cones and give more life for a while, found a few nice threads on how to. if the posi unit I got is "gone" I will send it back and get refund. I'll get it worked out one way or another. Thanks for the advice, one man can't know it all, thats for sure and sometimes I need help, so I ask for it. Now my brain is loaded with 2 days worth of 7.5"
information. next time I'll avoid the gov and cone style too. Maybe I should just take on of my 8.5 posi units and put it under the car, I was so trying to be lazy about this and buy something I could just wrench on for a few hours and be done. instead of starting from scratch welding and fabricating for hours.

big gear head

You can not recondition the Auburn the way you can the Borg Warner unit. The Borg Warner has the cones and axle gears seperate. The Auburn has the cones and axle gears as one piece. You can not cut the Auburn cones and shim the gears the way you can the Borg Warner. If you try to cut the cones in the Auburn the axle gear are going to be spread so far apart that the pinion gears are barely going to be making contact and the whole thing is going to bust, if it even works at all. You are also going to have an extremely large amount of axle end play.

Never go by miles and engine power when buying a differential. When I was running my rear end business I installed a few new Auburn units and 2 of them lasted less than 9 months, on the street. I know that there are many old Auburn units out there that are still working, but they have not been abused. If you do water burnouts or brake stands you will kill it pretty quick. If this unit that you bought is still good then I hope it works out for you. If it's not I hope you can get your money back. Otherwise you bought an expensive piece of scrap metal.

ddeennis

Got the center section in last night, looks good, I pushed the center pin
thru the middle and looked at the "centering of the spring plates" for which the springs ride, as far as the eye can tell the center pin holes look even all the way around both sides.

center pin slides in and out easy. anything else I could look at or check
to let me know it 's a good unit?

Sound like the unit has life left? what do you think?

big gear head

Only way to tell is by trying it on the road, unless you want to disassemble it. I've always had to use 2 bottles of GM oil additive with the Auburn. Don't use anything but the GM additive.