swapping the TC or the internals? Either way the TC has to come out, and its usually done by dropping it with the transmission; trying to drop the TC alone has frustrated many a good people.
A good idea is to hit the rear driveshaft with some penetrating fluid a few days in advance so you have some hope of getting it to collapse when you start the job. Its also a good idea to hit the exhaust nuts too.
Before you dive into the replacement job, check to see if the rear guibo has any cracking so you can order one in advance, same goes for the TC mount bushing.
If your new TC has stripped splines in the front output flange you might want to replace it with your old one, and consider if your current front driveshaft has stripped splines. Installing a stripped shaft will make you sad very quickly. Make sure you lube the splines properly when you put it all together or they will definitely bite you in the ass down the road. Molykote BR-2 Plus (I think) is the recommended lube, or similar. Your guy in TX should be able to order it from McMcaster-Carr in a small tube for less than $10. There is also a mod to add spacers to the front DS to push the splines further into the TC for better engagement, but if the splines are already stripped you are not going to get much extra life out of it.
Try to test the VC too. On a bench, the backyard way would be to lock the input to the TC somehow(with trans attached put it in gear or P) and hold one output and try to turn the other by hand. If there is very little resistance and you can easily turn the front output, the VC is likely damaged. It should require a lot of torque and take a few seconds to turn it 90 degrees or so.
If testing in the car, perform the jack test, which is really the better test. Look it up on youtube if you haven't seen it already. Jack the rear end up on a rolling shop jack and try to drive the car forward or rev with the front wheels on the ground. If the car moves with the rear wheels spinning at approximately the same speed as the fronts, the VC is in good shape. If the rears are spinning faster but the car still moves, there is some damage to the VC, and it's days are numbered, while if the rears just spin and the car stays put, well, you know what that means.
Swapping a good VC into another TC can be done without too much pain, but get your seals in advance and stay clean.
The bench test might be nice to confirm in TX before you commit to getting it shipped to you. As much as people swear the VC is good, its happened before that someone does not tell the whole truth.
For lots of detailed TC and iX specific information, search the iX subforum on e30tech.com, I go by the same name over there and that forum is regularly visited by many very knowledgeable iXers.
88 325IX TOURING DiamantSchwarz|89 325IX AlpinWeiss|88 325IX DiamantSchwarz
Last edited by supernaught; 10-25-2012 at 05:21 PM.