I have a 70s TRS unit, not too much experience with these.

I'm assuming the hydraulic fluid gets added to the dip stick hole since I don't see any other fill caps?
What kind of fluid does it take?
Hydralic fliud like you put in a jack? 80/90 Gear oil?
Brake fluid, ATF?
Just wondering if something I have in the garage will work or do I need some special mercruiser stuff?

Thanks
Evan

Most of the trim pumps have a label that defines the fluid. I've seen mechanics use ATF or 30W Oil--never seen gear oil used in trim system.

Good guess for your system would be to see what color the fluid in there now is. Red = trans fluid.

sae 30w...for trim system..

On a TRS tilt/trim system you have a motor-pump-resevoir unit just like everyone else's Alphas or Bravos that uses straight weight motor oil when available or 10w/30 otherwise. But there are two other DIPSTICKS associated with that drive system. The reservoir for the drive oil is located on the upper port section of the inner transom assembly. (and of course. that takes outdrive gear oil) And the transmission oil dipstick, located down at the transmission, for which you use the appropriate lube depending on transmission type. (MerCtrans, B/W 71 or 72, early or late series) I suggest you find an old dealer with the appropriate service manual and see if he will let you copy a few very important pages before you put the wrong lube in the wrong place! --- Jer