The Merkur Club of America Forums

To keep this from getting lost in the facebook cyberspace (I hate searching there), I decided to post this here and then people can link there or hopefully search here before posting on social media.

Here's a list of the replacement bearings and seals for the Supra Diff. Quick recommendation on these, as I've freshened/upgraded 4 of them with no issues. I always do 2 things minimum: Weir performance upgrade kit and a solid pinion spacer. I've gotten to the point of doing the pinion spacer by feel, which is actually quite easy.

The other things I do that do not require any sort of expertise in setting up a differential (only if working with a known good diff) are the front pinion bearing (no change in pinion depth) and all of the seals. The other bearings on the diff are gigantic. The rear pinion bearing is over 3.5" dia. and the carrier bearings are 83mm dia. I've only had 1 where the front seal let some water in and pitting occurred.

Without further delay, here's the P/Ns. All Timken except the Carrier:
Pinion Seal: 1177 (Rockland has a nicer one with a 3rd lip. OE does not have this. Not real necessary, but nice.)
Front Pinion Bearing: 30306M
Rear Pinion Bearing: 35028
Axle Seals: 710142
Carrier Bearings: Nachi 50BK8301

Hopefully helps out some people.

Yes, it does help.

Need to figure out drive shaft as well, even though every car has somewhat of a different configuration.

Thanks for posting!

my8950 wrote: ↑Sun Sep 29, 2019 8:14 pm Yes, it does help.

Need to figure out drive shaft as well, even though every car has somewhat of a different configuration.

Thanks for posting!

I've got some part #s for making a larger 2-pc shaft with the stock CSB. I don't know if everything clears, but the bore is the same as our bearings. 2.5" or 3" steel front 1310 U-Jointed driveshaft. Makes it easy to run an aluminum rear section. A few 4x4 places have adapter joints to go from the Toyota to a 1310. Just a thought.

Drive shaft flange, and Solid crush sleeve options "Marlin Rock Crawlers"

trueblue1968 wrote: ↑Wed Oct 09, 2019 2:16 pm Drive shaft flange, and Solid crush sleeve options "Marlin Rock Crawlers"

"solid crush sleeve" = Solid pinion spacer

Quick disclaimer on the front pinion bearing: the one I recently received was the correct 30306M, but the depth seemed off. Everything went in correctly, but the bearing contact angle is entirely different from the OE unit. THe cup and cone matched, but the OE bearing was very different. This created ~3mm difference in depth. Doesn't sound like a big deal until getting the pinoin flange on and realizing the dust cover is contacting the maincase. Luckily, the amount of pinoin spacer shims I had lying around allowed me to space it out. Measured runout on the flange face to about .004", which is good enough. I realized most of the time I get the Koyo bearings, and simply found the Timken one cheap this time around.

Thanks... now to figure out how to get it mounted.

Turbo wrote: ↑Fri Oct 25, 2019 8:18 pm Thanks... now to figure out how to get it mounted.

Same... I have CAD files for a weld-in solution from a friends rally car since JVAB is looking to have something like ~30 people to be ready with cash for another run. Obviously don't take the plans and sell it as a kit (or at least talk to the guy who created it first), but I can send you the files.

dunhamr1 wrote: ↑Wed Nov 13, 2019 9:36 am Same... I have CAD files for a weld-in solution from a friends rally car since JVAB is looking to have something like ~30 people to be ready with cash for another run. Obviously don't take the plans and sell it as a kit (or at least talk to the guy who created it first), but I can send you the files.

That would have been awesome... but too late, I tried waiting on JVAB - been on list over a year, figured he didn't want to make anymore, I ended up going MK route.

Turbo wrote: ↑Tue Nov 19, 2019 8:55 pm...I ended up going MK route.

Really? You get it already? Been going on 8 months now for the 6 degree beam modified for the Supra diff and fabricated TCAs. Things he claimed to have "ready" due to people backing out of a deal on the beam and then the TCAs were a run he was doing over the summer. Still waiting...patience running low.

Turbo wrote: ↑Tue Nov 19, 2019 8:55 pm

dunhamr1 wrote: ↑Wed Nov 13, 2019 9:36 am Same... I have CAD files for a weld-in solution from a friends rally car since JVAB is looking to have something like ~30 people to be ready with cash for another run. Obviously don't take the plans and sell it as a kit (or at least talk to the guy who created it first), but I can send you the files.

That would have been awesome... but too late, I tried waiting on JVAB - been on list over a year, figured he didn't want to make anymore, I ended up going MK route.

There's 10 names on the list of on Rallyanarchy...I set 30 kits to make it worth my time..These kits are good but I'm not in a position to lose money for nothing.....
Encourage others to go for the kit..It works, its fun but there has always been a problem in making and reasonable return on the sale as Xratti guys have big taste and are willing to spend what sems to me crazy money on cosmetic fooofy stuff but not real parts.
How many times in last 30 years have we seen "I'm new owner of a marvelous XR4 I just picked up for $400 and I need a full Cossie bumper/wing skirts kit..."

I'm going to ask a local Xrattista friend to do CAD/CAM files on the hardest part---the aluminum snout mounting parts and I'll shop around to see what those can be done at today.
IF!!!!!! those can be done more reasonably than before I'll see how inflation has affected the other parts....

I'll add this to the thread on Rallyanarchy.....

Oh just a mention..there is some anonymous guy over there advertising that he can make the easiest part, the CV adaptors for a nice low price of ONLY $275 a set.....try and recall that those sold for $55 each or $110 a set forever from the originator of this idea...me.

Thanks John, I'll be watching this channel and Rallyanarchy.