i have the stock auburn posi and 2.73 gears. would 3.42 gears fit in this posi, or would i need to get a new posi unit.

i found out i had a auburn posi by looking at the axle shaft housing and there is a stamped number. the service manual had the key of each number. just some info i thought ud like.

 

OEM gears won't work because they need a different series posi.
usually 3.08 and up will all interchange for one series and 3.08 and down for another.
But Jegs sells specially made gears so you can put 3.42's on your 2.73 posi without a spacer.
The part number is 836-49-0005-1 It costs $193.99 for Richmond gears.

 

so should i get the speacial gears or are they not as good as regular ones. if i got speacial gears is there a rebuild for the posi. so which is better.

auburn posi with speacial gears or

slp posi with regular gears.

is there a difference between the two other than that my posi is used.

 

I would go for the auburn with the special gears, those gears are just as strong as any other gears. The slp torsen take out is not bad for medium duty use. There is no rebuild for the auburn posi.

 

Hmmm. I just bought a Ford 9" rear with what the guy tells me is an auburn 3.70 posi unit in there. He said he burned up the clutches because he forgot to put in the posi additive. From what he told me, the posi works when it is cold, but it becomes a one legger when it has been driven for a while.

So, my question is: Are you saying that I can't get new clutches for the auburn unit?

 

Nope auburn posi's are metal on metal "clutches". When the case wears out thats it no fixen it. Now for you 9" I bet ya you got a stock traction lock which has clutches. This is a better posi than the auburn ever wanted to be, and you can rebuild it for about a 100 bucks, check your ford dealer or look on ebay.

 

Go to gearsareus.com, ask for Wayne. They got'em or can get them. Nice to work with. I just spent a bit today.

 

well, if the auburn isn't rebuildable y would i want to keep it. when it wears out i would need a new one anyway. does having the auburn posi mean i have 28 splines on my axle.

 

how long will the auburn posi last. after it dies i need to get a new posi and new gears again. so wouldn't it just be easier to get a posi now and gears or is the auburn gonna last a long time.

 

Auburn posi doen't mean 28 spline axles, I have owned a 26 spline auburn and a 28 spline.
I have also owned a GM 8.2 rear with a factory cone clutch non rebuildable posi that was at least 20 years old (because they stopped making the 8.2 in 1972 and this was in 1992) and it still worked fine.

I have an auburn in my '75 nova's 8.5 rear now, bought everything new except axles and housing and I plan on keeping the car forever.

 

so your saying it will last a long time.

so will i just need a ring and pinion, and a gear installation kit.

 

It depends on the history of it, if someone put two different size tires on the rear and drove it like that for a long time it would wear the cones out real quick. Just check it,, put the car in neutral, jack one tire up and see how hard it is to spin it. There should be some resistance, you may be able to turn it and be alright. There is a torque spec to see how many foot pounds it takes to get it to break loose but I don't know it.