Hey all, ran into another problem tonight and was trying to get help. I bought an OBX diff for my b16 tranny, I know there's a lot of discussion on being good or bad but thats not what I need to know.

I bought the upgraded washers and bolts from http://rbryant.freeshell.org/obx_washers.htm and installed them, i am fairly certain correctly, torqued every thing down and pressed on gear and bearings.



Cleaned the case very good.



And went to check the clearance to get the right shim. I had everything out of the case and measure .586 mm clearance. Spec is 0.0-0.1 mm and adjusted with shims. The smallest shim that Honda sells is a 1.0mm which would make it too tight, and none at all would be too loose.

I checked and made sure diff bearings were pressed on all the way, case was torqued down, and that the diff was fully seated in the race.
Is this gap supposed to be there?



I took the diff apart to see if something was keeping it from seating or something. Didn't find anything wrong. New bellville washers installed like )()()( which seems to be the most popular. Any help or suggestions would be greatly appreciated.

Thanks,
Aaron

 

Which differential bearings are you using? The standard ,B16/LS 6208's? Or the GSR/ITR ball bearings which have the raised center race?

I have a photo of a different style OBX. The openings cut into the carrier exposing the helical gears are round rather than square so I'm sure the rest of the housings have slight differences. The gap you're are concerned about is actually larger on the one I'm referring to.

All any of us are going to be able to tell you, though, is:

WELCOME TO OBX. THERE'S A REASON NONE OF US ENJOY INSTALLING THEM.

 

haha. I know I know I know, I jumped the gun before doing enough research. I used the bearing for a b16 tranny. I don't know the part number but I bought the b16 obx diff and have a b16 tranny case with b16 gears, except for 5th which is an ls gear.

 

bump

Still not solved.

 

If you have everything installed correctly, I'd return it to whichever OBX vendor you purchased it from, tell them you cannot shim it correctly due to the size of the carrier, and get another to try. OBX is just one of those products that have zero consistency other than for the fact that they are a PITA to install for several reasons. Of course, you have several people in various forums say they just "drop them in" and don't take time to even measure out for shims that just get **** lucky.

Those of us that actually care about thrust clearances or preloads (dependent upon bearing choice), where the ring gear matches up to the countershaft, etc. for bearing life and differential longevity simply could care less about OBX. Hence why those same professionals choose NOT to offer installation services with them.

Good luck! Keep us updated with what you end up doing.

 

Haha, thanks a lot. I've already opened this one up, replaced the washers and bolts and grinded filed off the sharp corners that OBX did not care about and I dont think that the store would take it back since it's been tinkered with. lol.

But what I did was go back through the diff, talked to rbryant and got the preload of the washers so that when the case is set on compared to when the case is tight is right about 60%, he advised 50% but I couldn't get that close. I put the diff back in the case and took a 1.0 mm shim and "machined" down to about 0.7mm and it got to 0.0 tolerance but it still spins just as freely as when the case isn't even on.

Thanks,
Aaron