I've been looking around for a while for a posi unit for my rear. What all cars had a posi in them? If you jacked a car up on one side and was able to turn the wheel would that tell that the rear is an open rear? Also if you jacked the whole rear up, but it was in park that wheels still move, is there anyway to check.

Today we found what I'm sure was a 15th anniversary TA. It was white with the blue striping around the wheel wells and above the GFX. Like in these pictures http://www.phoenixgraphix.com/transam/8415th.htm What are the chances that the rear has a posi in it? We turned the wheel(in park) one wheel turned forward, the other went backwards, but does that tell if it's a posi, open, or both. We're unsure of what it was. It seemed like a pretty rare TA, but was unsalvage-able. It had some seats, Ive never seen before. They had extendable leg rest, and netted head rests. Im also thinking it had a locking gas cap, but im unsure, considering we looked at 7 other cars too.

Also is there anyother tricks for determining if its a posi without removing the cover?

There's a nice looking eaton posi(used and rebuilt) for $150. Would that be a good deal? It's for a 3 series carrier, and my rear was originally a 2.73, but I'm replacing the gears with 4.10. Is there any possibility I could put the 3 series in my 2 series since I'm switching gears? Or if I put gears for a 3 series, would it fit?

Also how could I tell if the rear has 26 or 28 spines?

What would disc brakes be worth? The guy that has the rear is coming up with a price for us and I want to know about what it is worth. It may also be a 9 bolt. What exactly are the differences in the 9 bolts and 10 bolts? Would the posi fit in either?

Thanks for the help.

 

any car or truck with the 7.5 rear could have a posi carrier. the best and only 100% sure way to know is to pull the cover and look.

 

Well we cant get to the cover to even attempt to pull it off, unless we are planning to buy the rear or the whole car. How much would a disc brake rear from the 15th anniversary TAs be worth, about what would be a good price to pay for it?

I read somewhere that, if the car is in gear(not neutral), if you spin one wheel, the other will turn the opposite, but if its in neutral both wheels will spin the same way. Since we cant put the tranny into neutral is there anyother way we could tell if its a posi, without removing the cover. And whats the possibility of that rear having a posi?

 

What's in the diff depends on other car options.

The 1984 TA will have 26 spline axles. Gear ratio could be 3.23, 3.73 or 3.42 depending on if the engine is a LG4 or a L69 It also depends on the tranny and if it has the G92 rear end option code. A G80 RPO code will say the car originally came with a posi. If you can get an axle code off the diff, it will also tell you what's in the diff providing it's still original.

Without pulling the cover, you'll never know exactly what's in the diff. Anyone can easily change the gears or carrier in the past. Since all the third gen diffs are interchangeable, the entire diff could have been replaced in the past.

 

Without pulling the cover, you'll never know. Period. - Even some posi units will let the wheels turn opposite when not under load. As for the axles, again, the only sure way to know is pulling the cover. It's been WAY to many years since these cars were new to know if the rear is factory or not and/or what is or isn't in it.
- The pre 89 disc brake package is not really any better than a good drum brake package. Also it is very hard to make a 7.5" 10-bolt survive with a 4.10 gear. Case flex is the death of them, and the smaller pinion will have more issues with the same amount fo flex. 3.73 is about as low as you can make survive decent.

 

Yeah, I was afraid of that. I wouldn't want to spend $200-400 for the rear components, and just have them break. But I really dont have the $2100 to spend on a moser, or ford 9". Where is the cheapest place to get a 12 bolt or ford 9" ready to bolt in? It sucks not being about to afford stuff but wanting to do it right. I'm going to be spending $2000-3000 on the engine soon. And that money wont get paid off till quick enough to put a 2100 rear in the car I still have paint, and interior to worry about.

EDIT: Cheapest I found so far was a currie 9", but I still have to buy the posi, gears, and brakes. How they hold up?

And I'm guessing a 4th gen 7 5/8 rear isn't any better in strength?

 

that's right, 4th gen rears are only slightly better, and that's mostly due to them being newer, with less wear.

 

Try finding a junkyard 9" center section. Should be able to buy it pretty cheap. Then get the housing and axles from Moser - about $1000. Moser sells the "bolt-in" housing and axles as a package w/o the center chunk/gear/posi.
As long as the jy center/gear/carrier is in decent shape, put it in as is, start saving some $ and get a good posi carrier and the gear you want. That would let you spend the $ in steps, all while still being driveable.

- If you go this route, you'll have to make sure the carrier you get has the correct spline count to fit the moser axles.

The jy center chunk would still save you some $ even if you went ahead and bought a gear and posi carrier.

 

Yeah, but if I do that then wouldnt I have to weld it? I'd have to the spend $400 I saved on a decent mig welder to weld it. Then $400 for the posi and $150-200 for the gears, $100 for the axles.. and the torque are mount wouldnt be there...

Hawks sells a 9" Ford for a Camaro for 2100.. is that any good? It comes with the posi, and axles, but does it come with a my choice set of gears also?

 

- Moser sells the 3rd gen spec housing and axles for around $1000. Meaning it comes ready to bolt in, just no center chunk or brakes.

 

Oh right I completely forgot that what the center chunk actually was... I was thinking you meant the pumpkin parts with the axles tubes cut off. But yeah that's completely do-able, and will save quite a bit of money. If I got the center chunk, that gears, and a posi, would those be good enough so I wouldn't have to spend a whole lot more? The only problem would be the torque arm bracket... could traction bars take that place of a torque arm? If not, is there some other aftermarket piece I could use?

Thanks for the suggestion though.

 

If you went the route of the Moser housing/axles, then all the factory suspension will bolt up. - If you wanted to eliminate the tq arm you would have to completely change the rear suspension to another system.

A center chunk would drop in IF the carrier has the correct axle spline count to match moser axles. If not, you would need to change the carrier in the center chunk, meaning go ahead and get the proper gear, new posi(carrier) and a set-up kit.

 

Well I wouldn't want to get rid of the torque arm, but since the original center pieces didnt have a torque arm bracket, i figured id ask to see if traction bars or a 4 link would take care of that problem.

To buy a center section for an thirdgen with gears(possibly posi im not sure) for $900, which doesnt really save any more money. Anyone know of a place where I could buy the cover, without the carrier. Also what spine are the moser axles?

 

Even the aftermarket center sections don't have the tq arm mount. The tq arm mount is tied to the housing, thus comes with the moser housing/axle package.

 

Ahh ic, so all I have to get is a front cover, with posi and gears. Should I go to the junkyard to find a whole center chunk, or just get the lid and buy the gears and posi from an aftermarket place? Also what spines are the new Moser axles? and the average junkyard 9"?

Also, if I bought a moser 9" and got someone else to setup the gears, would it make any kind of whining? Or is that only the moser 12 bolts?

 

hey i'm new here and was doing a search and found this thread I have an 84 trans am 15 anniversary and I'M SELLING THE REAR OUT OF IT ALL 15TH ANNIVERSARY TRANS AM'S HAD 3.73 POSI IN THEM RPO CODE GT4 AND J65 DISC BRAKES IF THE GUY STILL WANTED THIS REAR IT IS UNDER MY EBAY AUCTION MY SCREEN NAME ON THERE IS MIKERTDAKOTA OR YOU COULD REACH ME AT GOVENORCAMARO@YAHOO.COM AND i HAVE ABOUT 10 CAMARO'S AND 6 TRANS AM'S I'M PARTING OUT

 

Nah, Im not interested in that rear end anymore, but thanks any way. But I am still wanting to know if I get a moser 9" rear housing and used my own gears would it make a lot of noise? If so is there any other company that offers just the housing for around $1000?

 

Moser is the only company I know of offering the axle & housing package at $1000. - A 9" has no reason to make any more noise than any other rear. Proper set-up is the key to a quiet rear, although some brands of gears tend to be noiser than others.