Hi!

Just bought a Mugen(I think) clutch LSD to install in my ITR tranny. The tabs have already been removed in the clutch side housing.

When I compare the dimensions of two oem diff vs the lsd with the ring gear on, the gear on the lsd is more/closer on the clutch side (higher on the pic). Everything thing else is withing specs. I removed the ring gear and there is no "shim" ring. I just see the 4 bolts to open up the lsd. The problem it creates is that it doesn't drop all the way in because the ring gear hits the casing near the countershaft bearing.

Is there supposed to be a "shim" ring between the lsd and the gear? Can I create/machine one and put it there to solve my issue?

Here is a pic. The middle one is the lsd.

 

Ok. I've contacted the person that sold me the LSD with the gear and he told me that it didn't touch the casing. He also told me that it didn't need/have any shim.

So I mesured everything again and, like I said, I would have to machine a stainless ring (other material? aluminium?) of 2mm that would go between the lsd and the gear. That would solve my problem but would potentialy create another.

When I put the gear on the lsd, the gear is centered and doesn't move side to side at all. But if I try putting 2mm flat washer to evaluate the results, it creates a gap of .1mm total, side to side movement. I could use a feeler gauge, center the gear and torque the bolts. But would it hold in place centered? Am I paranoiac for .1mm here or there is a real potential for problem?

I would prefer to find out why it was working before (from what the seller told me) and now it's out of specs. I think I have two choices: give it back or work around the problem. I would prefer keeping the lsd.

 

There is no shim ON the diff. Just in the case.

Is the ring gear mounted upside down?

 

It is mounted upside down compared to oem. It's the only way that's logical and is the closest to oem ring gear placement.

I understand that the shim should be in the casing but originally, there is only one shim on the transmission side casing. If I move the lsd more on the transmission side casing by, let say, moving the shim to the clutch side casing, won't it affect something like the shafts? I know I still would need to verify the shims with a feeler gauge but moving about 1.5-2mm won't cause any problems? Like I said, everything else on the lsd has the same specs as oem.

Thx

Edit: I just took a look a the service manual for integra and civic. They put a shim in each casing on for the GSR only (why?). So I guess I could put a shim on the clutch side to clear the gear from the casing (~2mm) and then shim or remove the shim on the transmission side casing?

 

The GSR uses tapered roller bearings and need to be properly loaded....you're using sealed ball bearings.

If the ring gear doesn't contact the case and makes good contact with the final drive gear on the counter....you should be fine...given the diff preload is in spec.

Take a pic with the diff in the case.

 

I saw that the GSR is using a different bearing.

My question comes down to this: can I put a shim ring on the clutch side casing so that the ring gear clears the casing, then mesure the transmission side casing and shim accordingly?

 

ball bearings from type r/gsr (not the taper rollers) are different from ball bearings for a ls/b16. the ones from gsr have a inner race that sits higher than the outer race...it's not flush. take a side view (inner bearing closest to diff) and if it's flush, you need different bearings. cuz on the diff side, it shouldn't be flush. sounds like you have a itr/gsr sized diff w/ incorrect ball bearings. i've had the issue of the ring sitting too high (contacting the pinion) with ball bearings on a ls/b16 diff and to find it had gsr/itr ball bearings. there is a difference (though the numbers and letters on bearings and bearings look physically the same).

 

basically it was roughly ~2mm though i didn't measure the inner race with a caliper or mic. friend measured the outer races were the same exact width with a caliper. inner race is wider total by about 2mm like you had said. and that could be simulated by putting a shim between the diff and bearings. should fix your problem without spending all that money for new bearings...those ***** aren't cheap. or if any of the good bearings you have, have the protruding inner race on one side...maybe you have the bearings on backwards. if so, just pull em and put em on the right way.

 

had friend measure differences and the inside inner race on the ball bearing for a gsr/type r protrudes or is higher than the outer race by ~.050" or ~1.28mm. the difference is apparent upon close visual inspection. if the bearing on the diff bellhousing side is flush, and it is facing the proper way, then you have a ball bearing for a ls/b16 diff (inner race measurement is ~ the same height as outer race) more than likely which would explain why it's sitting lower causing the interference with the casing where you describe.

 

I currently have b16/ls bearings on it and the width of inner and outer race are the same width.

I just did some test.

I removed the gear ring from the lsd, drop the lsd in the clutch housing and closed up the case without any shim ring. I then mesured with my feeler gauge what shim I would need and the shim I already have (was in the transmission housing) is what I need.

So I put back the gear ring on the lsd and used the shim ring I have and put it in the clutch housing. Then dropped the lsd on top of the shim ring and the gear clears the housing now. I closed again the case and I check with my feeler gauge, I'm within spec.

The only problem I see with this is that when I put my countershaft, the first gear is just touching the head of the bold securing the gear ring on the lsd. The gear still clears the first gear but is a little bit lower than the oem diff with gear but seems ok. A quick fix would be to shave the top of all the bolts.

Conclusion/resume :
- Put the shim ring from the transmission housing in the clutch housing
- Don't put a shim ring in the transmission housing
- Shave a bit off the head of the bolts securing the gear ring, and double check clearance
- And move on to finishing the tranny...

What do you think?

 

actually if you're set on using those bearings and you have 2 of them, gonna probably have to shim the top and bottom ~0.050"...not counting the 'c' shim in the gearhouse for a start. then just do the normal clearancing on the gearhouse side. definitely do a final check on the specs.