You're right, this model has the filler tube coming out the back under
the seat. The tube itself is a weird shape, as it has two really
sharp bends before it goes into the transmission, so it's not actually
straight down. It appears to go into the transmission about at the
midpoint between the top and bottom of the transmission housing
itself. But now that you mentioned the oil level could be up the tube
a ways, that makes sense now. I just wasn't sure how far up the tube
it was supposed to be. I think I'll call the JD dealer to double
check the part # on it. Thanks a lot!

--
Chris

"Louis Fookaiser" wrote in message thlink.net...
It varied from model to the next, possibly from one S/N
to the next. The 300 is a really old machine and most of
those had the dipstick under and behind the operator's
seat, with a more or less straight tube down to the
transmission. Later ones had a fill tube under the hood
and a sight glass.

On some the oil level was above the bottom of the fill
tube, because there are no seals between the hydrostatic
unit and the final drive, and the final drive is quite a ways
below the input shaft. The shape of the unit makes the
fill tube end up attaching somewhere quite low overall
so there ends up being oil in the fill tube.

But it varies from model to model. I tore apart the hydro
on a 420 not long ago but I don't think the 300 is quite
the same.

Louis