tslsa28

Hello. I've tried to sift thru existing threads but couldn't find a good answer to some differential issues. I have a base 2013 C6 that I use on the track. About halfway thru a 20 minute session I can sometimes smell what I think is hot differential fluid. Everything works just fine but it makes me wonder if the OEM differential fluid is not happy at high temps.
Is the OEM fluid synthetic?
Since I use full synthetic fluids for oil, brakes, clutch, power steering.. maybe I should go to full synthetic (if Redline, Amsoil.. are full synthetic) for the differential? If I do, do I need any modifiers, etc?

xBoostx

I found synthetic fluid in mine is '11 gs I added a diff cooler sense my car is A6 didn't bring one I noticed very hot fluid in mine as well haven't bother to check after the cooler but no problems before or after.

Lmk if you need some pointers on how to add a diff cooler as well as some pics.

hungryhippo

Check your axle seals.

tslsa28

Thanks. Are you saying the OEM fluid is synthetic or you are using synthetic? I don't to add a cooler if I don't have to but did you use a OEM cooler from a ZO6?

tslsa28

Thanks. There is just a tiny amount of dampness but no drips. I was thinking a better fluid would hold up better under heat and not get thru the seals.

hungryhippo

The heat is what will wear the seals. Not sure if the factory fluid is synthetic or not. The diff fluid should be changed often if you track the car anyway. I personally use redline with the additive already in.

davidfarmer

most common reason for losing diff fluid at the track is a slight over-fill. If you don't let the overflow drain completely before putting the plug in, it will swell when it heats and leak around the seals.

I've personally used Mobil 1 Gear Oil in my race car differentials, and will continue to do so. I'm not arguing that it's the best, but it's available EVERYWHERE and has always been good enough for me.

Check the level, change the fluid, and see if the problem continues.

Purple92

While I'm not completely sure - I believe the factory fill is synthetic. (DO a search on diff fluid, and you'll be up most of the night reading through all the threads.)

If I were you - I'd go ahead and change the diff fluid. Mobil 1, Redline, Royal Purple all make good fluids - use whatever you think is the best - many people believe that the better synthetic fluids come from different base stocks - so something like Red Line may be worthwhile (I've used their gear oil in a ZF gearbox for years - and I believe in the stuff).

I'd also suggest bringing an IR Temp gauge to the track with you - do about a dozen laps and pit - then quickly read the temp of the diff. The factory engineers decided a cooler was worth it on the Z06 - so there may well be a lesson in there.

xBoostx

No did not I used a small fluid cooler with light black nylon braided hoses see link..

I use Valvoline 70/90 synthetic with Quaife diff.

http://www.ebay.com/itm/CXRacing-Uni...VWwn0H&vxp=mtr