(DRIVETRAIN) Miata Diff interchange into 84-85 models
 

Just pulled out the 3rd member of my rear on me SE, and it is shot. Both the ring and pinion gears have excessive wear marks and heat damage. I guess I know why it was humming so bad. Anyway, since it is a limited slip, is it worth rebuilding? Should I take a chance on a used one? Or, assuming I have the money, invest in a performance rear?

Mike

Simplest would be to find a new r&p, then take it to a shop and have them put it back together. I probably have and r&p laying around if you need them. Mine would be the 3.9 gears, not the 4.1 in the SE's.

I would just rebuild, at least you know it's done right rather than buying used & dont know how long that one will last.

:icon_tup:

if you have the money, get a kaza for a 1.8 miata and some new gears. if you want shorter gears, get some kia gears

Trochoid,

Do you mean a 3.933 from an 83-84 12A, or a 3.909, from an 85 12A----just curious :-) Also, what shape are the R&P in? Is there "ANY" visible wear other than normal? I ask this because I thought that my R&P had normal wear until my step-dad told me that it was shot (he's an expert).

Mike

What is the advantage in getting the 3rd member for a 1.8 Miata?

well, it is a superior LSD unit. even the stock miata torsen LSD is better than our stock LSD. if you want even better, get the kaza designed for that miata.

im not sure if the miata gears will work, ill have to guess and say no, but i could easily be wrong

oh shit thats some expensive stuff. looks good but i can put a ford 9" in for that.

http://www.kaazonline.com/8309.html


kaaz's website is here.

http://www.kaazonline.com/

well thats apples and oranges

How about the KAAZ diff that is deisgn for our car? They are available from Mazdatrix.

I don't recall which parts car the gears came out of. Could be 83/84 or 85. I'll have to count the teeth and inspect for wear. PM me if seriously interested.

It appears that the Kaaz diffs at Mazdatrix are for road racing, drifting, etc. They are not for the every day driver. The stock set-up or the torsen is for the everday driver. I may be wrong however.

I will PM you as soon as I know what I am going to do.

Thanks

yo put a kia third member on the car

I was thinking about the miata rear. If I were to go to a junk yard and get a miata 3rd member, which year miata should I ask for? Will my stock axle shafts fit into the 3rd member? What is the differential gear ratio on a miata?

Thanks,

Mike

I've read from some members that the 94-97 Miata 3rd member is a "no hassle" bolt-in replacement for my SE. Is this true? I was also told that not all 94-97 miata rears were limited slip. How do I know which is LS and which is not, assuming the guy at the junkyard doesn't know. Will my SE axle shafts fit into the splines of the Miata?

How stock is your car?

I too would like to know since my SE LSD is starting to wear out. Mine is from a 85 SE. What would be the best miata to pull it out of?

earlier MIATA came with open diffy.

Pretty stock except for racing exhaust and 2Gen DFIS.

You want to take it from a 94-97 Miata, but make sure it is not an open rear. The locked rear (LSD) was an option on certain Miatas. I called two junkyards so far, and they only had to regular rears. They were, however, able to tell me over the phone whether the Miata rears were regular or LSD. If you do the swap, keep in mind that it is a lower gear ratio, I believe 4:30, so your speedometer will be off unless you swap the Miata speedo, if possible.

Mike

no its not a 4.30. Its only a 4.10.

94+ miatas. its not that hard to find the units. go to miata forums or craigslist

Great! If it's a 4:10, then it almost identically matches the SE.