I have a 73 240z with a 4spd tranny and a rear end out of a 73 240z which had an automatic tranny. I was wondering what kind of tranny fluid and rear end fluid you guys use and what weight to get. The fluids have not been changed in over 10 years while it sat.

-thanks

I'm a big fan of Castrol products. The Trans and the Diff both use SAE 90 gear oil. Since you'll be pretty hard pressed to find Straight SAE 90 in 2006, that leaves 75W-90 or 80W 90 personally I use Castrol Hypoy C. While in South Carolina I used 80W-90 which is probably the best bet for TX.

Nate

Double Post

Might want to think about going to a synthetic oil. Redline, amsoil, Lowers the temperature.

I use Redline in most everything that's not a motor, and either Mobil 1 or Castrol Syntec in the motors.

I recently refilled the diff and gearbox with Redline MTL. I noticed a big difference in the shifter, much smoother and not as much of a notchy feel. The diff is still a little noisy but after I changed it I noticed on the Redline website they recomend the 90W rather than their regular MTL (75W?). I think I will change it out.

Remember to flush out the old stuff prior to refilling. I ruined a good roadster gearbox that way due to crud and metal shavings that did not come out with the old oil.

Steve

You'll get a lot of different opinions on this question as everyone is passionate about the certain brands they use. For me it's nothing but Redline in my transmission and differential

what do you use to flush out the dino lube prior to adding synthetic?

do you just fill with flush and drain, or do you fill with flush/run car/ and then drain?

i can see taking the cover off the diff and cleaning it out first, but i doubt i want to attempt the same thing with the tranny.

I just used gasoline but a mild solvent like mineral spirits would be safer:dead:

Take a drive to warm up the old lube prior to draining it out. Then replace the drain plug and add about a pint of solvent and let sit for 10min to desolve the sludge in the bottom of the case. Drain, then flush again without the plug to wash out any remaining particles. Let it sit about 30min to let any remaining solvent evaporate, then chase it out with a little clean lube for good measure.

Be sure to clean the threads on the plugs and the holes good with a rag and some solvent to get rid of any grime that might prevent a good seal. Then refill with your choice of 90W lube (Redline:D ), and enjoy the ride!

Steve

I've been using Lucas 85 weight gear oil in my '71 it works great. I use Castrol syntec in my wifes Karman Ghia and it does make it run 10 to 15 degrees cooler and thats in an air cooled engine. MTC