Triumph Repair: 1964 tr4 crankcase nut torque specs, triumph tr4, nut torque

Question
Hello sir,

My friend is rebuilding a 64 triumph tr4 and cannot find the torque specs for tightening the crankshaft nut. I saw a previous question for a 68, and you recommended 150ft lbs, but i want to be sure before telling him. Thank you for your time.

Doug

Answer
Hi Douglas,

I don't remember ever quoting a torque spec for that long "starter dog bolt". The "Starter Dog Bolt" is set with shims at "10 minutes to 4:00 O'clock position while #1 piston is at TDC Then a locking plate installed to keep it in position. The books for the TR-3 nor the TR-4 quote a torque spec and both say to set it by shimming so it is in the position above.

The position is important if you need to hand crank the engine. Who does that any more? The few I did I set it by hitting it lightly with an air wrench and unscrewed it and adjusted with shims and run it in again that same way until I had it in the correct position. Then as I remember there is a locking plate that holds it in position. I never hit is hard enough with my air wrench to go to 150 ft lbs though, even though it is a large diameter bolt.

Howard