Using a Eclipse Turbo Fwd Obx Diff? - 3000GT/Stealth International Message Center

Mw3X · 08-08-2009, 07:51 PM

So my brother's Stealth's Diff is starting to let go and Ive been researching alternatives to the stock Fwd Differential. Ive found that the Fwd turbo eclipse's tranny internals are pretty much identical to the 5speed 3/s's besides the case. can anyone confirm this? I figure instead of putting a stocker back in and waiting for it to blow and possibly taking part of the trans case with it, why not put the Obx lsd in as long as the eclipse fwd turbo Diff and the 3/s's is the same. Sounds like a smart alternative to me as long as im correct. If you have any info please chime in. Thanks

Black_Sunshine · 08-09-2009, 11:57 AM

they're identical.

Stealthee · 08-09-2009, 01:24 PM

Well OBX sells them for the 3000GT FWD too, but they are the same.

You may want to do a quick search on here about the OBX diffs. I beleive it was Supercar who checked them over and found some faults with them that needed corrected before installation.

Also a diff doesn't "start to let go", its either in one piece with all the teeth, or its broken.

benson8277 · 08-09-2009, 06:45 PM

They are the same, You would have to have the gear installed, I have one and it was great until my Super charger went out, now the tranny is forsale 900 shipped. I had a bigger 5th gear , new carrier bearings and other minor parts installed, it's still in the break in period. I sent it to TRW Jon does good work..

Hope this helps

Mw3X · 08-09-2009, 09:55 PM

Thanks guys thats what I was hoping, With supercar reworking them do you think he just found a flaw that would cause damage or fail at higher power levels or extra stress? even if both the awd and fwd obx diffs are flawed? because being n/a I dont think anything catastrophic could happen under its power level unless its a serious design flaw.

Stealthee · 08-09-2009, 10:09 PM

I'm NA and have taken out 3 diffs and a 2nd gear. Improper shimming can cause major issues and cause axles to get eaten.

Black_Sunshine · 08-09-2009, 11:39 PM

Brian, supercar only sells the awd obx diffs. those are the ones he modifies. i believe the obx n/a ones require some shimming. just ask on the dsm forums.

Stealthee · 08-09-2009, 11:41 PM

Oooh, either way, even Ondontii said he had issues with the OBX diff.

Ondontii · 08-10-2009, 02:35 AM

You want to replace the Bevelle washers inside, replace the bolts with longer ones (they don't engage all the thread in some obx's).

Also, test fit an axle into the diff to make sure it slides in. They tend to be machined slightly too small so its hard to get the axle in. Usually it just requires polishing either the axle or the diff. I would polish the diff to get a little more clearance.

Shims for the differential are something that needs to be done regardless of where you get your part from (even OEM). You need the proper bearing clearance (mine required slight preload). These are the shims for the bearings, not anything inside the diff.
OBX's often require much more/less shim then OEM because of quality control. I know someone who had the bolts in his OBX back out so next time he is putting his back together with loctite.

If you get one, make sure you get a warranty card and register it. I never got one years ago so my warranty is worthless. Ive thought mine broke once but it was an axle that snapped off inside the trans from wheel hop on dry slicks (water box closed).
The cool thing about the OBX is that I could just put a rod through from the other side and knock out the axle piece instead of having to remove the trans and take it apart. OEM open diffs have spider gears and shafts that won't let you do that.

Ondontii · 08-10-2009, 03:50 PM

Oh yeah and I improperly shimed this diff once and it twisted the splines of an axle because the diff was not staying centered in the trans when I launched at the track.