9x7 cars have a I'm bearing but Porches sorted that out shortly after 04. Reman and 9x7 engines have updated ims shaft, bearing, and stud that always breaks. They now use a 12mm stud with chamfered edges for o ring instead of 8mm with straight cut groove that made it about 6mm. If you have a 00 to 05 without a L&N bearing and you drive like grandma it will definitely fail. Ims bearing's fail from lack of service but mostly low RPM, babying it, compression braking to idle, etc. When you drive them like a pissed off teenager they typically don't fail. Plus 9x7 cars require splitting the case to replace imsb, 35 to 40 hrs labor plus all gaskets and seals.

 

Having changed out the IMSB on our 02 Boxster, I can tell you that the effort is much shorter than the 35 to 40 hours suggested by Rollsgto. You have to remove the tranny, clutch, and flywheel to get to the IMSB. Using the tools purchased from L&N, we changed out the bearing about an hour. There might have been about 10 hours consumed to pull and reinstall the transmission. So, for a Boxster, its about a 10 to 15 hour job.

If the engine has to come out of the car, most mechanics are looking at 15 to 20 hours to R&R the powertrain. So, for this scenario, you are looking at 20 to 25 hours for the job. Obviously, the amount of time is model dependent. Total repair should be less than $5k depending on labor rates.

 

For what it is worth, I changed out the IMS on my 60,000 mile, 2000 C2 996 because of all the forum hand wringing about my engine being on the verge of grenading. I used the LN Engineering items, and it was installed professionally by a great shop. I was presented with a perfectly good removed single-row IMS bearing when I picked the car up. It was smooth and solid, with no signs of undue wear. For what it's worth.