When do I change the tranny and diff fluids? What mile increments??

 

first 10k miles should be sufficient for the differential fluid because of the break in period so you'll get rid of all the metal shavings.....transmission fluid I'm not sure as I changed mine out at 16k and I swear it was as clear/clean as it came from a new bottle itself....

 

The maintenance schedule outlines the interval for tranny fluid. Go take a look. Although I consider it to be a bit on the extended side, as long as the tranny works OK, I see no reason to do it any sooner. However, it's cheap enough and easy enough to do that I do it once a year anyway.
The diff fluid, on the other hand is not so clear. This is encompassed into the catagory of things to "check" annually. I do this one every year also. For those who track the car, it would be wise to change it more often.
While the diff fluid can take quite a beating, the tranny fluid can stay relatively clean for a very long time. However, this doesn't necessarily mean the additives are still viable.

 

I changed my diff and tranny fluids for the first time at ~10k and will do so again when it comes out of storage in the spring (24k). I plan on doing both annually due to the low-cost of each and how quickly it can be done.

 

I do it (tranny and diff.) every second engine oil change.wich,in my case,is once a year. ;using Redline Mt-90 for the tranny.,and 75W90 gearl oil for the diff.

 

Engine oil 3k royal purple , tranny 20k gm synchromesh friction reduction, diff. 15k mobile one it works great for me thats just me everyone is different

 

royal purple is crap for what they charge for it

 

Way too expensive,for what it's worth;try Amsoil.!!!

 

why do you guys say that have you tried it compare to mobile 1 just curious i have tried both thats why i ask ? i might change to amsoil for the engine ?