Miata 97 4.1 Torsen diff ID'ing and swapping - help| Grassroots Motorsports forum |

accordionfolder HalfDork
11/30/14 4:35 p.m.

Hey guys, I have a cheap line on the torsen 4.1 with housing. All the googles have lead me to believe this will be a Type II torsen, the type I could be ID'd by looking in the filler hole for worm gears, the type IIs are a bit different, but I can't find a good line on how to ID them; anyone have the low down? The guy seems trustworthy, but I would like to confirm for sure.

I know that going from a 1.6 to a 1.8 diff will need axles and driveshaft, will any 1.8 axles and drive shaft do, or will I need to get a specific type since this is off of a 97? I keep reading about some difference in axle bolts, but I'm not finding it clear what they mean.

I'm planning on getting a Kia Sportage 4.7:1 R&P and swapping it into this diff and replacing the 4.3:1 1.6 diff that is on the car now. That little engine needs all the help it can get.

Thanks guys.

atm92484 New Reader
11/30/14 5:14 p.m.

Pop the axles and see if you can look straight through. If you see a pin its an open differential. If you can see straight through then its either a Type 1 or Type 2 Torsen. Otherwise you'll probably have to pop the aluminum housing. The Type 2 housing is more enclosed (gears not visible).

accordionfolder HalfDork
12/1/14 3:06 p.m.

Thanks!

Uppity for the final say on required parts for the conversion and any additional know-how on ID'ing them.

tpwalsh HalfDork
12/1/14 3:27 p.m.

The 94 has stub axles, where the 96 and 97 4.1's don't. They have 1 peice axles. I think the changeover was in 95 sometime. I think you can pop out the stub axles and use the one piece units, or just go with the 94 spec axles.

EvanB GRM+ Memberand UltimaDork
12/1/14 3:36 p.m.

Any 1.8 axles and driveshaft will work, that is all you need. Either the 2-piece with the stub or single piece will work.

accordionfolder HalfDork
12/1/14 4:20 p.m.

Nice, that's what I like to hear.

I think my diff is getting ready to pop, it's making a lot of noise, though most people seem to say the drivetrain on the 1.6 is just noisy.

EvanB GRM+ Memberand UltimaDork
12/1/14 5:16 p.m.

My 1.6 diff made a lot of noise for a year or two until I swapped it, never gave up though. I ran it behind the turbo 1.8 for a bit and it never got worse.