Overfilled trans + diff?
 

'93 RX7, 5 speed

I bought 4 quarts of Royal Purple Max Gear 75W-90 and took to a mechanic to swap the fluid in the manual trans and diff. I had read that it needs 2.65 quarts for the transmission and 1.35 quarts for the diff (4 quarts total).

Well the shop mechanic said that the trans took 3 quarts and the diff took 2 quarts... he had to go pickup an extra bottle to finish the job.

Now I'm like "WTF"... did he overfill it?
He says thats what it took, right up to the fill hole. ??
What do I do?

bump.

Anyone?

I don't recall the exact factory specified capacities off-hand, but those you mentioned look about right....maybe a little more in the diff. Hopefully the car was level.
If he never spilled a drop, that would probably do it. But essentially you fill until it runs out of the fill hole, so there may have been some waste and he needed at least some of a 5th quart. If he was REALLY conscientious, he changed the gear oil in the shifter reservoir too...which takes another cup or so along with grease at the pivot points. In any event I think I bought 5 quarts total of NEO a year or so ago when I did it myself...knowing there would be a little spillage.
What do you do? Pay the man.

I recall buying 5 qts and having barely enough for both.

Nowadays I use different oils in the diff and transmission because the best diff oils are not compatible with synchros.

David

Thanks guys.

You can't overfill the Trans or the Diff as the "fill holes' are on top..so to speak(higher than the drain holes)
As soon as oil comes out the Filler hole,it is Full and you just Put the Plug back in and tighten.