So am I to understand that a Miata LSD fits the front Sportage differential? It that's correct, I'd be more inclined to go with an LSD than an ARB because of price and easier installation.

Ron, the first 2 photos are of your new diff in my old 3rd member. it was a b!tch to get the original ring gear bolts out because they are lock-tight-ed AND torqued, but it is done, also, the ring gear doesn't wanna go easily onto the new diff carrier, it is almost a press-fit, so i just slowly tightened the bolts all the way around until it sucked it up.

about ring gear mesh with pinion after carrier swap: let me start by saying the guy who designed these and most 3rd members was a genius. the side-to-side position of the ring gear and diff carrier is adjustable by tightening and loosening the bearing retainer rings, so yes, the ring gear and pinion (which was not removed) fit just as well as stock when it was all said and done. the backlash was less than .03, but i don't have accurate measuring tools to get any closer than that.

the ring gear is indeed 7" across. i don't know what i was thinking before when i sadi i measured it at 6-3/8, maybe cuz the carrier was still in it and i couldn't get around it to measure properly. anyway, it's 7".

the splines match- BUT- i didn't check to see if the right side gear had the groove for the snap ring in the end of the inner axle shaft. the left (long side) shaft doesn't have a snap ring because it is retained by the 4 bolts holding the frame mount onto the housing. i will chack that tonight.

back to the genius of 3rd member drop out diffs- if you don't remove the pinion, there is no trouble setting the diff back up the way it was. it's just a beautiful operation.

ok, what else? ummmmmmm.....

oh, yeah- found some chipped side and spider gears, don't know how that happened, but there they are.

also, if someone wants, now that i have it out, i will weld this diff and you can buy it from me as a spool. not sure how much, but not too much, with core.

and gary- sorry, man, i don't have very good measuring tools, but i will try my best. if ARB has access to another Miata LSD, they can take measurments off it. might be easy to find in your neck of the woods. i will take some measurements, but like i said, they will be dull and less precise than they prolly should be for this sorta work.

Hi Dave,

As long as the short side has the same snap ring groove (size position etc.) it will be ok for us. I would be very surprized if the spline tolerances are any different between the Sportage and the Miata but the snap ring grooves might be different. The Miata and the RX-7 with 7" ring gears do NOT have the same size snap ring groove but the position is the same so the Miata guys only have to change the snap ring it's self.

If this does work out, we should also be able to use the clutch type or the viscous type LSD's from the RX-7 in the front of the Sportage. <img src="/forums/images/graemlins/smile.gif" alt="" />

My rear interchange with RX-7 turbo diffs is not looking as good. the RX-7 turbo has larger axles. <img src="/forums/images/graemlins/frown.gif" alt="" />

It's too bad that the housing on my Safari van wasn't designed as well as the Sportage one. It's all with shims. It was a bear when I put a Torsen in my van, but well worth the added traction.

Good work fellas!! Keep it up and please keep us posted.<img src="/forums/images/graemlins/kewl.gif" alt="" />

Hmmmmmm, I might be interested,

depending on what I can find on ebay

Great to see everyone pulling together to make things happen.

May I make a suggestion that we organise ourselves into particular tasks???

For example,

Me: ARB Locker F/R

Ron: Torsen F

Dave/Dennis: Lifts/SAS/Barwork

???: Lower Tcase gears

???: Dual Tcase

???: Upper/lower ball joint spacers/replacement arms

Small teams OK to share the workload, or individuals across groups as expertise decrees.

I realise some of these projects are finished or well on the way to being finished, but they will all be facilitated if we all have a co-ordinating person to communicate with.

Not trying to commandeer, just trying to keep the momentum.

Axe, any chance of a "sticky" on this and the ARB thread


***DAVE*** you might be able to measure the ring gear PCD, inner ring gear diameter (or the Torsen hemisphere dia, if it a close enough fit to the ring gear) and bolt dia from the Torsen.

Done.

Has anybody actually measured a newer 28 spline rear axle? Is the diameter 27mm like the front 26 spline halfshafts or is it larger?

Moving this question to Rear Diff thread.

wanted to add- there is a bit of a problem with this set-up. there is no groove in the side gear for the retaining ring on the right-side [short side] inner axleshaft. there is nothing to retain the axleshaft at all. the Miata LSD can be disassembled and a groove put into the part, but it does not exist in stock form. it shouldn't be too hard, but it will be time consuming, to a degree and must be put back together carefully.

Yes Dave, the timing of the worm gears is very difficult in the Torsen.


Dave....check your PM