Triumph unit 650 gearbox

[joe90]

Help required!  I am restoring a 1970 model Triumph TR6P unit 650 twin (similar to Tiger 650).  I am having trouble setting up the gear box to properly select gears.  The Haynes manual shows a plunger that screws into the bottom of the case to hold the cam plate in a certain position.  My engine does not have this plunger, just a spring arm attached to the back of the gearbox inner cover.  Does anyone know the correct position of the cam plate, how to hold it in position during reassembly and the correct position of the quadrant on reassembly? or perhaps know where I might be able to find the answer.  I would be grateful for any information.

[L.A.B.]

Unfortunately Haynes manuals try to cover too many models in the same book so can cause a certain amount of confusion as there were many differences that do not get mentioned like the camplate leaf spring that was only used for just over a couple of years (late 1970 to 1972 models). The design then reverted back to a more normal plunger assembly.

Also the instructions given for positioning the four speed camplate given in the Haynes book applies to an earlier version gearbox (with a notch in between second and third to hold its position).

So according to the Triumph factory manual instructions of the period the camplate should be set to the fourth (top) gear position, (the camplate is turned so that the spring is in the notch when the camplate is turned fully anti-clockwise when viewed looking at it in the gearbox) and not set between second and third as shown in the Haynes book.
After the gear cluster is fitted, the inner cover is fitted with the quadrant held so that its upper tooth lines up with the centre of the main shaft.

[joe90]

Thanks very much for coming back with the answer so quickly, it took a couple of goes but managed it in the end.  Not easy to decide exactly where to set the quadrant but the position that works is in fact the highest it will go - close to the 1st peg.  I also marked the camplate with tipex to ensure it did not move out of 4th when the cover is replaced.  I can see why they reverted back to the plunger, I can also see why horizontally splitting crankcase were invented.  I think I had better get the proper workshop manual.  Thanks again, your help is very much appreciated.