Triumphrat

lovecuba

Both manuals (Triumph and Haynes) do not show torque settings for the camshaft fasteners or crankshaft end nut. Why would this be? These settings, I would believe are quite important.

I have read that Mr Pete indicates that 40lb is sufficient for the c/shaft fasteners but can find no info re the crankshaft nut.

JohnA

The genuine Triumph manuals are a disappointment. I had the same query when rebuilding my engine. The answer I got was to torque both camwheel nuts and the crank pinion nut to 70ft/lb.

Have you tried finding the recommended torque figure for the gearbox sprocket nut? In my manual it tells me, in the gearbox section, to tighten it to the setting given in the general data section, but look in GD and there it isn't! No wonder most T140s seem to have their gearbox sprocket nuts loose. The figure I was told was 80ft/lb for this (and high strength Loctite). But since then I've seen somewhere that it should be 100ft/lb.

Does anyone have a definitive list of OIF torque settings, covering all the important ones, that could be published on the Tech Tips section?

lovecuba

No John, I could not find the setting for sprocket nut either. The purists will probably do Me over here but My method at getting it really tight was to place a wooden hammer handle through one of the circular holes in the rear sprocket (so that it wedged up under the swingarm) select 5th gear, apply Loctite 243 to both threaded surfaces, place all My available 3/8 socket extentions together (3 x long, 3 x short) place them through the socket, apply generous pressure to rear brake and use muscule. The muscule overcame the braking capacity and thus the wooden handle came into play.

JohnA

I've just performed some quick calculations and, according to these, almost breaking a mallet handle with the brake on equates to just about 100 ft/lbs, so you should be fine!

Mr.Pete

The T160 manual gives 58 ft-lbs for the gearbox sprocket nut on a 5-speed.The thread for a 4-speed is slightly smaller.I'd say 55 ft-lbs would be plenty for a 4-speed.Stan Shenton recommended 60 ft-lbs on a racing 4-speed.

Some use 50 ft-lbs for the crank pinion nut.That seems a lot when the rotor nut clamps the engine sprocket with 40 ft-lbs.On a 650 with the early 26 tpi stud,the rotor nut is only 30 ft-lbs.It doesn't take much torque to drive the camshafts,compared to the torque on the engine sprocket.I can't imagine any problem with 40 ft-lbs on the pinion nut;go to 45 if you like.

Some use 80ft-lbs on the camwheels,and I'm sure they crush the cam shoulder into the camwheel in the process.Some use about 55 ft-lbs.At 35 ft-lbs there'd be enough clamping force to drive the cams to about 10,000 rpm,even if no key was fitted.The intake camwheel nut is also self-tightening,because of the oil pump.

I really can't see a problem using 40-ft-lbs on the camwheel nuts.I've never seen one loosen off,or a pinion nut either.
I've seen and heard of rotor nuts loosening.

lovecuba

Thanks for that Pete. In the end I used a 40lb setting for all three nuts, and a dose on each of medium strength Permatex locker.