Swap to Mazdaspeed Diff
 

I am running a '96 NA with a '96 Ford Explorer 5.0 HO and T5 five speed. Maybe 260-280 HP. Autocross and track day car. Currently running a 4.1 Torsen with the passenger side break point welded. I found a deal on a '04 Mazdaspeed diff with CV's and drive shaft. Going to swap for the stronger axels and diff. So some questions.

1. Should I have the "wing" on the passenger side welded or are the MSM wings stronger? What about the bolt on kit? Or, can I swap my current welded diff case with the MSM diff case?
2. Is the MSM drive shaft the same as what I have now or will I have to have a new T5 to MSM shaft made.
3. What should I replace while I have this all apart? Bushings, bearings etc. Poly bushing?
4. The MSM is 4.1 also. Should I swap gear ratios while I have this apart? What ratio? 3.9? 3.6?
5. Any hints on doing the swap.

Thanks in advance for the help.

Hi,

I would personally recommend that you upgrade to a better diff since you have the whole thing apart. The ford 7.5 or 8.8 are both good options and will not be overly expensive to do. At your power levels the Mazda diff will likely hold if its not abused but as its a track day car I would want something a little more robust and there are many ratios available in the zone you need, i.e. 3.45, 3.73, 3.9 are easy done. For your car a 3.73 ratio will give good kick and still have good top end....4.1 is a little short with an approx. 6250 rpm limit of the HO engine.

For all the effort that you will go through for the MSM diff change over I would switch it out, its almost the same effort to fit and the cost wont be too far different either.

Cheers,

Thanks for the reply Engineer. I got a steal on a Mazdaspeed diff and axels so I think I'll give it a shot. Just going to swap the diff while leaving the case in the car. Found out I can use my welded carrier with the Mazdaspeed gears. Same driveshaft. Fairly easy swap. I may end up doing the Ford later but for now I am giving this a shot. Cheap (around $500) and fairly easy. I'll post here with my results and experience.