1985 R80RT transmission oil capacity

[Gregjo]

First a quick introduction: My dad has been a BMW man for longer than I've been alive. He's owned 4 BMW's his entire life....starting long, long ago. He rides them 'til they drop....or until his kids ruin them (much more likely). I don't know what happened to bike #1, but I know it lasted decades. But when I was 4, my 6-year-old brother put sand in the gas tank. That ruined bike #2. A little over 20 years ago when I was 16, I got in a wreck and totalled bike #3. The current bike (#4) is a 1985 R80RT.

 

My dad doesn't use the internet, so he called me to see if I would ask a question for him. I hope I found the right forum. If not, then slap me down.

 

He lost the manual, and he'd like to change the transmission oil. What are the specifications for a 1985 R80RT's transmission? What grade of oil, and how much? He recalls a technician once telling him that the aluminum screw for checking the level is highly susceptible to stripping...and that he should never touch that screw. Is there a kind soul out there that can help me out with this information? I've been googling for hours, but can't find the transmission oil specifications.

Thanks!

[Wooster]

1985 R80RT's trans oil capacity is 800 ml; oil itself is 90 wt hypoid oil, found at any bike shop and/or auto supply store.

The oil level check procedure is similar to oilheads, i.e., trans oil will just touch the fill's female threads (as it's horizontal, the oil level is at six oclock).

BTW, rear end oil capacity is 250 ml and again, when full, the oil level is just touching the bottom most female threads (not fill's but small bolt's hole at end of rear drive); oil grade is same as trans.

 

Wooster

[notacop]

On the R Bikes, I usually filled the resevoir until it just started to seep back out of the fill hole. Got lots of trouble free miles that way.