TRIUMPH TIMING GEARS
We often get questions about Triumph cam gears and which marks to line up during engine assembly.
To put it simply you always us the cam marks which line up with the wood ruff key.
For this article we will assume the bike is stock and not modified with extra gear stamping. Adding additional timing marks is general practice if you fit aftermarket performance cams and are timing off a few teeth. It is not terribly common to come across extra gear markings but worth mentioning.
If you find the timing marks on your machine do not line up just after removing the cover don’t panic. These marks will only align every 94th revolution. This is due to the number of teeth on the intermediate gear. If you have disturbed the gears best to start fresh.
Installing the gears after a rebuild is easy as you can see which marks lines up with key way.
Resetting the timing where the gear nuts are installed can be a bit more involved.
Seeing that each gear stamping coincides with a cam key way there may be confusion in which cam gear
key way is being used. Best to remove the nuts if you have any doubt.
Note: The camshaft gear retaining nuts have LEFT-HAND threads.
The crankshaft gear retaining nut is RIGHT-HAND thread.
Removing either cam or crank timing gears will require the factory tools. This procedure is detailed in your Triumph factory workshop manual.
Cam gear extractor 650/500: 60-2213 or JRC 20-130,
Crank gear extractor 650/750: 61-6019
(500 Triumph use 60-2213 JRC 20-130)
PREUNIT TRIUMPH GEAR TIMING MARK DIAGRAMS:
1947-1955 FACTORY TIMING MARKS
1956-1962 FACTORY TIMING MARKS
UNIT TRIUMPH GEAR TIMING MARK DIAGRAMS:
1963-72 650 FACTORY TIMING MARKS
1973-77 750 FACTORY TIMING MARKS
1978-ON 750 FACTORY TIMING MARKS
1959-74 500 FACTORY TIMING MARKS