WTT: My 3.9 torsen for your 4.3 torsen
 

Just like the title says: I have a 3.9 from a NB 6-spd but I'd like to have a 4.3 torsen from the NB 5-spd. You pay shipping both ways and we're good.

Thanks!

Whole pumpkin or gears only ?

Diff and Carrier. I don't want to take it apart and reassemble.

May be interested in the swap
 

New to Miata's (just purchased 2005 mazdaspeed miata with 58k original miles, all original vehicle), but I don't like the high revs on the interstate. Would this differential that you have change that for me? If so, definitely interested, but don't know much about removing the existing one. Can you work with me on that?

I think that your car already has the 3.9 rear end (although a different LSD design). I'm not certain.

Mine is stock - 2005 MSM
 

I think it is either the 4.3 or a 4.1, not sure - but it is either what you are looking for, or the next one to it - I saw your classified, and I am just looking to lower my RPM's on the highway, because that is mostly how I drive my cars.

(I did just get an email response from another Miata owner, and he said I need the 3.6 to do what I want the car to do) - SORRY, was trying to help us both!

Word. Here's a gearing calculator to see what you need: Flyin' Miata : Technical info : Gearing calculator

Thanks - this differential needs to GO.
 

Thanks! Great chart!

I need to go to the 3.63 (or maybe even the 3.3 when it is available) - put larger 205 55 15's on it already, but not much of a difference (but definitely a better ride). Now that I have the comfort issue dealt with, need to get the gearing fixed. Thanks to all of you for your help.

Willing to sale it and ship it then ? Shipping both ways is prohibitive for the whole thing...

Not really. I need to end up with a 4.3 torsen. This seems like the easiest way. What's your estimate for shipping & what does the diff/carrier weigh?

Edit: Obviously, we can remove the back part with the mounting ears to cut down on shipping cost & size.

bump it

Shane, the MSM has 4.1 gears if it is stock. The R&P will swap with any 1.8 Miata but the half shafts on the MSM are bigger so you want to just get gears. OP, I have a set of low mile 4.1 R&P I would trade for the 3.9. I could send the gears now and you could return the 3.9 at your convenience. I'd like them by the end of February. Not 4.3, but let me know if you are interested. Not to thread jack but anyone else with a 3.9, I'm WTB/WWT. Thanks.

I'm not interested in the 4.1. It's not the ratio I want and even if it was, those diffs are a dime a dozen. It's not a good trade. Not to jack up your post, but anyone would be better off selling the 3.9, buying a 4.1, and pocketing the extra $$$.

Where are you located? I'd be interested but I'm not sure how much the shipping would be.

I'm in Ypsilanti, MI. which is in the SE.

Are you in Dalton, OH? I know some folks around there.

No. I'm all the way in Alabama. I'm worried shipping will be high BUT if your not in a big hurry I'll be near Sandusky Ohio in March and I could bring it and swap

USPS calculator says it will be $42 to ship (using Huntsville, AL).

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Bump it...

I'm interested. 4.3 in a '99 with 50k miles. Always had synthetic gear oil.

I'm in mid-north Indiana so we could work out a meet/swap.

I do not have enough messages to PM here, but if you PM me with your e-mail we can follow-up there.