I recently had my LSD rebuilt and a 4.78 ring and pinion put in. I've driven roughly 130 miles sparingly so far. I've heard you need to replace the oil after a while but I'm still a bit in the dark on what to do now.

How many more miles should I drive smoothly?
What viscosity of oil is recommended? I like to drive this car hard so I'm not sure if 75w90 is too thin.

I am so eager to drive spiritedly I can't stand it!

Thanks,
Appa

 

Anything with a itch type setup or a clutch itself, I always give it a 500 mile break in period before i change the oil and romp on it. That's just me personally. 75W90 or 80W90 would be fine, but make sure to use a good gear oil such as Amsoil, Motul etc.

 

Was the actual diff unit rebuilt with new clutch plates, springs etc? In that case I think there is a break in period and you want to drive around in figure 8 pattern for some time and change the oil.

If just the new ring and pinion was swapped in I do not think there is a requirement to break it in.

 

If ring and pinion gears are lapped,there is no break in period for the gearset.

 

Also a good thing to use a limited slip oil additive.