My 89 TA has a 3.08 rear gear. I am planning to do a differential swap for a torsen T2R. To do this you need to have a 3 series carrier. I have heard that the 3.08 gear fits into a 2 series carrier. From the factory would the 3.08 gear be in a 2 or 3 series carrier? Could I determine this by physical characteristics?

Thanks for any help you can offer

 

A quick look in the Summit Catalog says that 3.08 and lower numbers have a different carrier than the ones numerically higher than 3.08. As to the series of these carriers, I don't know. I would call the company and ask them.

 

Something to keep in mind: an '89 car with a 3.08 gearing just reeks of 9-bolt. Check your rear before you order that T2R because it'll only fit 10-bolt rears (I have yet to find a torsen diff for a 9-bolt.)

 

This is deffinetly a 10 bolt. I do have a 9 bolt as well. I was going to install it until I heard about the torsen t2r and decided that this was a better way to go.

 

yeah 3.08 is 2 series and anything under.

above is 3 series.

 

You could use a ring gear spacer to make 3-series gears work on a 2-series case. You could also get thick gears designed to allow higher than 3.08 ratios to work on a 2-series case. Just some options.

 

The goal for me is to have rear disc brakes and a torsen t2r as my rear differential. That said I will need to buy a replacement axle. If I find a non posi rear end can I install the torsem differential for a limited slip rear end? Or do I need to start with a posi unit?

 

The rearend doesn't matter. All the housings are the same. If you're going to step up and buy axels make sure to go with 28 spline ones. I used a pair from Moser, and love the quality. Much better than stock. Get your Torsen to match the 28 spline axels.