So I just replaced my blown transfer case and found that the pinion gear was shredded. What I didn't realize is that the (heavily contaminated) gear oil also lubricates the drive shaft yoke bushing via oil channels. Some debris seems to have gotten in there and visably scored the bushing surface (sorry I don't have a pic of this). The scores were deep enough that it didn't initially want to come apart from the TC, but since they're 'concave', it does slide easily back into the new TC and spins freely. I just don't know if this will mess up the new TC.

Of course Mitsu doesn't sell just the yoke, so I may have to buy an entire 3-pc driveshaft/ 5 U-joint assembly if it needs to be replaced $$$$ .

Any suggestions?


(this is just to show the part. I don't have a pic of the scoring.)

 

If i were you I'd ask around to some drive shaft shops and the sort to see if they can fab you the piece you need before you go OEM.

 

How did you blow the Tcase ??

 

As long as your splines look good in the yoke and the scoring is not to bad on the shaft of the yoke be okay. Try using some emery cloth on shaft if there is scoring due to the seal rubbing.

 

Splines are fine. The issue is gouging on the machined shaft surface due to chunks of metal lodged in the oil channels of the mating surface on the old TC. Sanding it smooth would require removing a lot of material, and I'm not sure how close a fit this needs to have.

 

Good question. It made a noise on decel for a month, but we couldn't diagnose it (not a whine). Finally realized it might be a Tcase issue when it was still there even when coasting under no power. The next day it failed catastrophically a few laps into a road course under full power.

I believe there may have been a lubrication issue when we changed the clutch in the spring. The fluid coming out after failure was downright nasty, and I'm mad I didn't check it sooner. I will now be changing Tcase fluid w mitsu spec every 5,000 miles. The car also makes nearly double stock torque, so that was certainly a contributer too.

 

Man is it pitted bad? if so yeah need replace it. You can get it turned but then your seal might not seal.

 

note to self, change transfer case fluid. Cheap insurance I guess (I've changed it once, but I guess it's about time again!)

 

Additional note to self.....if you know your t-case fluid is nasty dirty and you road race your evo and then your t-case is whining dont go race the next day.

 

Yeah, hindsight is 20/20 .

It wasn't making a traditional T-case whine, and had we known the fluid was dirty prior to failure, it would have been changed. Moral of the story I guess is to check/change your fluid every oil change.

 

Whats crazy is the fluid changes on my 2007 GMC Sierra are not until 100k miles regular use.

 

Lol... 100k miles... yeah. Might be time for me to go back to GM (Z06)...

It was great having my VIII RS when Mitsu was doing free maintenance/fluid changes even if you voided warranty.