The Triumph 2000/2500/2.5 Register Forum

Hello, Can someone advise me the size of the nut that holds the prop flange on the gearbox output shaft, I intend to replace the oil seal and want to make sure I have everything to hand, Thanks in advance Kenny.

They are 3/8 UNF and 1 1/8" long, tightened to about 25ft lbs (or as tight as you can reasonably do them!)
Just a question - why do you want to replace the original? When they have been removed previously, have the nyloc nuts been partially rounded by the use of an open ended spanner? I use a thin ring spanner on the head, and a thin wall 1/4" drive 9/16 AF socket on the nut with a 1' long breaker bar, as it's usually not possible to get an opened spanner on the nut fully and this risks rounding the flats if it slips. This way it's possible to break each nut without risking an opened ended spanner slipping.

As above. Nice Stahwille ring spanners for me. NO open enders . Not 1/4" but 3/8: x 9/16" socket.
Tony.

Thanks for the replies, Sorry if did not make myself clear , I actually meant the nut that holds the prop flange to the out put shaft,

If you mean the large castellated nut / nyloc nut on the end of the mainshaft rear flange that bolts to the front end of the propshaft, then they are 3/4" UNF. The specified torque is 100-110 ft lbs.

Done this myself recently, you need something handy to hold the gearbox flange when you unscrew the retaining nut.
I'm not keen on wrenches around the collar, so use a piece of flat bar like the photo below - bolt to the gearbox side of the flange and hold while you loosen and re-tighten the flange retaining nut. Its a piece of 25x10mm flat bar about 250mm long with a 10mm hole with a relief ground out to clear the flange collar. Anything similar will do as long as it is stout enough not to bend.

Pete

johnnydog wrote:If you mean the large castellated nut / nyloc nut on the end of the mainshaft rear flange that bolts to the front end of the propshaft, then they are 3/4" UNF. The specified torque is 100-110 ft lbs.

The socket required is 1-1/8" AF.

Thanks to all who replied? Job done !! less than one hours work, all well .