GTM Differential Cooler Kit install, Anyone done this?

AkumaMS

Unfortunately, this is just not correct. We were on the track this weekend, and the rear diff had a failure(I will elaborate in a bit). The car has a cat back exhaust and out prototype intakes. The tire/wheel combo is 18x10et20 on all 4. The tires are Toyo R888 255(f) and 295(r)s. Ambient temp in the 80s'.

I was able to run the first 20 minutes with out incident. The second session I started to push the car a little more, say 75% to the limit. The car started to get a little loose on turn in and hard braking. Once I pulled off the track you could smell the fluid. The diff was also making a ton of noise on light turning in the pits/garage area. You could feel the wheel try to lock up.

Basically, the oil got so hot it melted the drain plug magnet. When fluid gets that hot, it loses its viscosity. The OS Giken diff then did not know how to lock the plates correctly, and we had to end the race weekend. The bearings and races looked good, but the bearing in the final drive assy is binding from excessive heat.

We are in the process of making a kit, but I would encourage anyone who is planning on tracking the car....get a cooler solution ASAP.

__________________
John Shafer
Owner/Calibrator
Akuma Motorsports LLC
http://t1.gstatic.com/images?q=tbn:A...ncVpndgs-nSyng

Valentino

Same here, Ambient temp was in the mid 90s'.Diff was acting weird on my second session on the fifth lap pushing really hard. went back to the pit and what you just explain happened to me.
Though i damaged the diff. towed the car back home from the track, and the next day towed it to the dealer. Mechanic drove the car the sound and the locking on light turning was gone! I drove the car back home and luckily i didn't damage the diff. probable the oil cold down and got back some of its velocity. changed the diff oil. Oil was lighter and the magnetic plug was full of tiny grinned metals. oil also smelled burned. I put in a new OSG oil and nothing happened after that.

Car drives like nothing happened to it. I just had to go down from 5 laps to only 2-3 flying laps. I give the OS diff 10/10. for taking that much beating. the rest of my mods is in my sig.

Ya a diff cooler is a must if your going to track your car regulary.

__________________
Lou Fusz Nissan | KW V3 | SPL rear camber and toe bolt | OS Giken LSD | Nismo Diff cover | Engine Oil cooler | F.I. TDX Cat Back 18" Resonators | F.I. Resonated Test Pipes | Injen cold air intake | COBB AccessPORT | JWT Clutch Flywheel |

AkumaMS

Turns out the diff is OK. Strangely enough, the oil seal near the front of the diff(where it connects to the driveshaft) had melted out of spec and was causing the final drive to bind up a bit. Once the seal was out, the assembly rotated freely. I did not have to swap the bearings.

I HIGHLY recommend the OS Giken fluid for their diff. It has a 250 weight rating. This is DRAMATICALLY different from the Motul 75 140. the Motul is a fantastic fluid, but it just can not match the viscosity of the OS Giken fluid. The OS unit is very reliant on the oil to lock the diff properly, so I would stick with the OS stuff for anyone using this unit.

On a side note, the guys at OS said many people have overheated the diff and they withstand the abuse. So if you have overheated it, there is a very good chance you are OK. just get the cooler on there and change the fluid asap.

Thanks guys.

John

__________________
John Shafer
Owner/Calibrator
Akuma Motorsports LLC
http://t1.gstatic.com/images?q=tbn:A...ncVpndgs-nSyng