How Often Should Fluid in Diffferential be Changed ?

[RockyTop]

I have a 97 GTS that sees the track (road courses only) about 5-6 days a year. The rest is spent driving in the stop and go of Atlanta. It has 23,000 miles on it and I have replaced the diff. fluid once since I have owned it. How often should the fluid be changed ?

 

[Chuck 98 RT/10]

I don't have the manual handy but I think it's 15K for street driving.

On my track car I change it about every three events.

When you pull the fluid out look at the color. If it's a lot darker than what you're putting in then step up the frequency.

 

[RockyTop]

The dealership says I need 2 qts. of something called 75-140 synthetic fluid and that I need two bottles of friction mofifier. Is he right ?

 

[Geoff Green]

You need 41oz of 75w/140 synthetic axel lube and 4 oz of friction modifier. Since you wont get it all out you can start with the 4 oz and add the rest till it comes out the fill plug.

 

[RockyTop]

Thanks all !

 

[Frank Parise]

Service manual says you should check rear axle fluid every 12 months or 7500 miles. Complete change after every 3rd or 4th track event is what I do. My Viper Tech recommends 2 bottles of friction modifier instead of just one as suggested in the service manual. My car is strictly for track use. Total capacity is 45 ounces. When you are full, it will spill out the side of the drain plug hole. 37 ounces of MOPAR synthetic 175W-140 MS-8985 fluid plus 8 ounces of MOPAR limited slip additive MS-5630 is what I use.

 

[Frank Parise]

Last post should have read 75W, not 175W...sorry for not proffreading.