Thanks for the info on parts/manuals. Now another question. I have a '75 Volvo 140 transmission with overdrive in my 544. What is the correct oil for this transmission/overdrive and do the transmission and OD share an oil sump? The Volvo dealer says 90 weight oil but my Triumph OD uses 20W50.

A '75 would be a 1st year 240 (oddball year with a B20), which could have a 140 type M41, or it could have the later 240 type gearbox (rare). If the 140 box, the book calls for straight 30wt. I personally use straight 40. But it seems modern 80 or 90wt gear oil is fine too. I have my reservations.

If its got the M46 or whatever gearbox came in 240s, it probably would call for ATF.

--
-Matt I ♥ my ♂

They share a common oil supply. There is no clear consensus on what does and doesn't work in an OD equipped transmission. The reality seems to be that almost anything works, from 30W motor oil to ATF to 90W gear oil to Redline MTF. I think nice clean oil of any decent type is sufficient. If your OD is old and tired, some slightly heavier oil might coax another 50K miles out of it.
--
I'm JohnMc, and I approved this message.

Yep, got 80/90 GL-5 gear oil in one of mine, 20W-50 in another, and ATF in a third. Can't tell any difference.

I use the cheapest 20W-50 oil without any fancy chemical stuff in it because the o-rings on the pistons (the ones that hold the pressure in the system) will detoriate resulting in complete loss of the OD. And removing the M41 gearbox from a 544 is a pain, I can tell from experience
Michael