Triumphrat

RetroRod · 05-23-2009, 06:37 AM

A call for help to all experienced gearbox mechanics.

I'm not game to post this at Britbike as the topic has been done to death there and I'd be flamed the minute the post hit the board. My experience is you'll be more forgiving over here.

I've read extensively on the subject and have the workshop manual as well. I understand all the theory and reckon I have it right up to reinstalling the inner cover. (I have installed a new leaf spring, only because I do not want to visit this place again anytime in the foreseable future)

Having reassembled the gearbox and checked it twice, I'm happy it is assembled OK. I can rotate the cam plate and locate all 5 gears OK. I installed the innercover with the g/box in neutral, and had no trouble with the cam plate wanting to move out of neutral. So' here I am in neutral and I have followed the manual's advice for positioning the plunger quandrant. (I might add here that I've found the gearbox to be in good order).

Positioning the plunger quadrant is not rocket science, and I'm happy that this too is right, or very near right (within one tooth on the plunger quadrant anyhow). I'm pretty certain the plunger quadrant is engaging the cam plate gear OK as there is just the slight amount of movement you'd expect when meshed correctly. If it was jammed, it would be rock solid.

Problem is that when I mount the outer cover and attempt to shift gears, nothing!! neither up or down, nothing wants to move.

I've done this several times now and would be glad to find just a few gears, but nothing!!

Historically, the shift has given trouble on the down change, finding false neutrals. The up change has always been reliable.

I'm a nervous wreck!! I'm not the best mechanic in the world, but nor am I the worst. There is something I'm missing here, but cannot see it.

I am starting to suspect the shifter mechanism. I have not had the shifter mechanism apart, but it looks to be OK. There is nothing obviously wrong with it, and it seems to work OK if I put the outer and inner covers together, it shifts the plunger quadrant up/down OK.

God only knows what is going on here, but if anyone can suggest something, I'd be very grateful My sanity is in the balance!! RR

OzBloke · 05-23-2009, 09:35 PM

RR,
My suggestion would be to put the inner cover back on, indexing the quadrant by the book. Then with a large flat screwdriver (and a small scrap of wood to protect the casing) try selecting all gears using the screwdriver as the lever between the casing and the quadrant. You might have to rotate the rear wheel slightly as you select, to get all the gears aligned. Leave it in first gear, and then double check the indexing by measuring between the bottom of the first (lowest) tooth on the quadrant, and the inside of the inner cover wall directly below it. This should be 40mm (Thanks to GulfCoastDave for this advice several years ago).

If all is well, then put the outer cover on, and try selecting the gears with the gearchange lever. Again, you may have to rotate the rear wheel a bit to enable the gears to mesh.

Let us know how you get on.

RetroRod · 05-23-2009, 11:59 PM

Thanks mate,

Useful suggestion to a difficult post. I'll give it a go today and advise. RR

RetroRod · 05-24-2009, 02:37 AM

Hi OzBloke,

Problem solved!!

:

In my original post I said this was not rocket science, and this remains so. I also said I was not the worst mechanic in town and this needs to be reviewed. I am the worst mechanic in town, though I now have much experience in assembling and unassembling the inner and outer cases of the '72 Bonneville.

Problem turns out to be me. Indexing for neutral when the box is in
2nd gear is not recommended for one's patience or sanity. Next time I might just take more time looking at the diagrams (when all else fails check the manual)

At school I was always placing round pegs in square holes and wondering why they didn't fit!

Thanks mate, your post did promt me to try your suggestion and then look at things once anew. Much appreciated. RR