Just curious on thoughts of using 75W -90 oil in my transmission/rear axle, that way I can just keep one oil and pump on hand for the truck and my new car. I do know I used 80W-90 in a new car once, and it did not work very well....
What year/type transmission/rear-axle?
53 3100 with original 3 speed and torque tube rearend.
I really think too much can be made of oil viscosity.
Years ago my wife's Honda called for 10w-40 in the transaxle.
One of my customers had a 1960 Benz and it called for ATF in the manual transmission.
I think the only risk of using lighter oil is the potential of increased leakage.
I would use 85-140 in the old truck trans. & rear end. In the new car use what the owners manual calls for. In the new car you don't change it often enough that the plastic squirt containers won't work.
George
I was kind of thinking it would be fine, I just mentioned the new car because I used 80-90 non synthetic, and it didn't shift real well, I put the 75-90 synthetic in and it worked flawlessly. There is simply no way to utilize the squirt bottle to fill the new car, the hole is simply buried. I change the oil often enough I want a real genuine industrial oil pump, I have about 6 of those cheap little plastic pumps all broken to some extent or another, I swap parts around till I get one to work. One of them didn't even get one stroke, I pushed it down and the bottom blew off. Right out of the box. I'm so done with them..... But thanks for
I was kind of thinking it would be fine, I just mentioned the new car because I used 80-90 non synthetic, and it didn't shift real well, I put the 75-90 synthetic in and it worked flawlessly. There is simply no way to utilize the squirt bottle to fill the new car, the hole is simply buried. I change the oil often enough I want a real genuine industrial oil pump, I have about 6 of those cheap little plastic pumps all broken to some extent or another, I swap parts around till I get one to work. One of them didn't even get one stroke, I pushed it down and the bottom blew off. Right out of the box. I'm so done with them..... But thanks for the input.
Get accustomed to grinding gears, especially on downshifts. Synthetic gear lube is too slippery to let the synchronizers do their job with the heavy gears and the inertia involved with stovebolt transmissions- - - -SM-420's in particular. Use 90 weight straight mineral oil in the transmissions, 90 Hypoid lube in the rear end.
Jerry