changing rear and tranny fluid, what's the best?

[D111]

I want to change the fluids in my T5 transmission and the rear fluid in my BDR

Any recommendation on the best to use?

And how much I will need to purchase for each?

thanks

[PANAVIA]

If you can get it - Mobil1 Synthetic ATF 4 qts for the the T5 -

For the Diff, I do apologize- I do not know the specs for the BDR.

Remember Diff Fluid sometimes requires a friction additive, and some diff fluid has the additive mixed in, do read up and know what you are using.

[RICK LAKE]

D111 First name would be nice. How many miles are on the fluid? Are you having a problem with the rearend of trans shifting? If not leave the fluids alone. If you are racing, that's a different story. Under semi normal driving conditions 25K to 50K miles is a normal change unless for abuse. If you are having a shifting problem or posi issues then there might be something else wrong and adding new fluid will only fit the issue for a short time and may do more damage than good Fine out what the problem is. Talk to BDR first before changing things. I am not saying that it's not a good idea to do if you have a new trans and rearend installed in the car and have 500 miles on it. this breakin will get all the partials from machine work done in both assemblied that didn't cleanout. Good luck Rick L. Ps If there is a warrenty on either part, You better be 100% sure you are using the correct replacement fluid. Wrong fluid WILL void warrentys. Calling BDR would be the best bet.

[Bartruff1]

I can't imagine why you would change them..but...it is your car...

[D111]

few years old with a few thousand miles but it's the original fluids I believe.

I remember speaking to backdrift in Florida and them tell me they like to change the fluids once a year or so but it's not mandatory.

I figured can hurt to put premium fluids and get rid of the originals?

[bobcowan]

I like to change all fluids fairly often - like every 2-3 years for light duty/low mileage use. Not sure it really needs it, but it makes me feel better.

The transmission calls for Mercon auto trans fluid. Unless you're racing and need additional heat protection, there's no advantage to using anything else.

The rear diff is a lot like the engine. The fluid you need depends on the use. High heat and heavy duty use (racing) requires synthetic fluids with a higher viscosity. Light duty use has no need for the expensive synthetic, and should use a lighter weight fluid.

A clutch type LSD needs a friction modifier.

[Cashburn]

We use Royal Purple in the diffs. Nothing magical in a T-5.

[D111]

Originally Posted by Cashburn

We use Royal Purple in the diffs.

thank you Jay

which royal purple and no friction additive? Would two quarts for the rear be enough?

I'm surprise that the T5 can hold 4 quarts.

[D111]

upon further research I guess it's better just to leave well enough alone.