Is it better to use 30wt motor oil which was on the tag on the new trim pumps, or is Trans fluid OK?

I have Valvoline straight 40wt and Valvoline Max life Dex/Merc trans fluid.The trans fluid is what I have been running in my steering and trim tabs.

My trim system has been drained when I striped the boat. It had trans fluid in it but it was dark.It was this way when I bought it.

I would appreciate your thoughts.

also what weight is the Dex/merc transmission fluid??

Thanks
Rob

Rob I have allways used amsoil trans fluid in everything but the drives and engines. My pumps and rams have lasted forever in all the boats I have run.
40 wt oil is for lawnmowers.

I agree. AMSOIL Trans fluid.

I think trans fluid is 15W oil, which is the same as power streering oil, yout dex/merc oil should work just fine.

Looks like everybody is using trans fluid.thanks for the replys.


Anybody else?

Rob

I use Merc motor oil without any problems. I always figured it's one less thing to carry onboard and easier to find if you get stuck.

Service manual says to use 30wt.

I run the straight 30W oil Mercury reccomends. Trans fliud is much thinner. I only use what weight oil manufactures reccomend in my cars, trucks and boats. I am funny that way.

Mercury don't even run there oil in drysump 6s. And as far as I know they don't refine any!Amsoil comes in different weights.. Huber or Bam transmissions would never last under big power with 30 WT mineral oil recommended by Borg Warner.

mercruiser power trim /power steering fluid that way you know you are using the right stuff