Triumphrat

OzBloke · 09-18-2006

1977 T140V. Over winter, did a major engine overhaul, new valve guides, valves, springs, main bearings, big end shells, sludge trap. Steering head work. While I had the unit apart, I also noticed the 2nd gear layshaft bush was quite worn, so replaced it. Also replaced gear selector quadrant springs and plunger springs.

All back together, engine runs beautifully, but on first run had trouble selecting any gear above 2nd. Took the gearbox apart again to make sure I’d put it together right, and layshaft bush was not binding. All seemed OK, and bush was moving fine. Put it all back together again, checking gear selection was OK by rolling backwards/forwards in garage – engine not running. Got all 5 gears without too much trouble.

Took it for a brief run around the back streets near home, and had some minor trouble getting it into 3rd on the initial take off. After that, I couldn’t get anything but 1st, neutral or 2nd. Rode home in 1&2.

Checked for gear selection when cold – again could not select anything but 1N2.

I know I’ve done something wrong, but I’m having some trouble figuring out what.

Any suggestions would be greatly appreciated.

Thanks
Pete
p.s. Daughter #1 is getting married in 5 weeks, reception at home, and SWMBO has got me slaving on fixing up the house, so not much time to work on the ride.

Mecchanica · 09-19-2006

Any chance you may have reversed a gear on a shaft...so that the iincorrect dogs are (not) engaging? Or that the quadrant isn't timed correctly? When you pushed the inner gearcase cover home, how did you set the quadrant?
OH wait.......you say you get all the gears when it isn't running.....OK.....it's clutch adjustment. If the clutch drags, it can be a ***** to change gears.
Since you have already assured yourself that the gbx is ok, move to the clutch.
First, make sure that the primary chain isn't too tight. Check it while sitting (or someone is sitting) ON THE BIKE. Check BOTH the drive and primary chain at this time. If the drive chain is too tight, it can also tighten up the primary. Get the drive chain tension right, then adjust the primary.
Do the standard clutch adjustment routine.......slack off cable adjuster all the way, remove inspection plug in primary, loosen the locknut, with small screwdriver on nut to keep it from turning, loosen the screw and then run it down until it contacts the rod. Do this several times. Then back out the screw 3/4 revolution. Spin nut down snug and then tighten while assuring that the screw doesn't turn with the nut. Adjust slack to get an eighth inch of lever end movement
If this doesn't do it, you'll have to go inside and adjust the clutch pressure plate lift.

GulfCoastDave · 09-21-2006

Pete,
I had a time of it getting my '78's transmission right but finally figured it out & it has been fine for about 500 miles.

Of course being sure the pinions & forks are all in correctly is essential, but my troubles had to do with getting the shift quadrant aligned. I found the factory manual to be no help at all in this respect. A Triumph dealer from the 'old days' gave me some tips & it worked out fine.

What worked for me was... when I slid the inner cover on, the vertical distance from the inside of the lower case flange to the bottom of the first tooth of the quadrant was maintained at 4 cm.

Please check this against other information available as I don't claim to be an expert.

I took the dam thing apart so many times, I was having dreams about it at night.
Right now, I'm assembling the transmission of my '79... so all that background is now coming in handy.

Best regards & thanks again for all the electrical know-how.
GCoastDave

Mecchanica · 09-21-2006

Since he gets all gears when the engine isn't running, the problem is much more likely the clutch. Another thing which will give two seemingly opposite results is plain plates which are glazed or too smooth. The clutch will drag, causing the difficult shifting, and slip under load. If you have the clutch apart, have the plain plates sandblasted with coarse media, like coarse garnet or frit. The plain plate needs to have some tooth.

CaptRussell · 09-21-2006

Hi ya, FWIW I had a very annoying problem which was sorted once I realized that the guide plate, which the quadrant plungers run against was installed up-side-down by the PO.

It would appear that the symptoms are similar to what you have described and were very erratic.

When you have the outer cover off you might like to check this one out.

OzBloke · 09-21-2006

Guys,
Thanks for the responses. I was pretty happy with the clutch setup when I put it toghether after the engine re-build. No slip, it ran true, and adjusted perfectly.

I'll rip the cogbox apart again this weekend, and triple check I've got everything in the right places. I'll let you know what I find.

Her indoors will not be happy with no work on the hacienda.......

Pete

GulfCoastDave · 09-22-2006

Pete... to clarify my earlier posting...
Per the factory manual... I assembeled the box with the cam plate in the neutral position. Once all pinions were on the shafts, I moved the camplate to the first gear position. Then, when putting on the inner cover, I used the 4cm dimension etc.
Best regards,
GCoastDave

Mecchanica · 09-23-2006

I's still try the clutch plain plates. They can look just great, but be too smooth to do the job. Especially in the 70 and later bikes, which use engine oil in the clutch. For these bikes, best to use non-"energy conserving" oils, which have additives like Molybdenum Disulfide, bad for the clutches.

GrandPaulZ · 09-23-2006

I like to put a bit of texture on the steel plates by rubbing them in a circular pattern on a smooth concrete slab.

It definitely works a treat.

OzBloke · 09-24-2006

Here's the latest.

Took the outer gearbox cover off, and using a large screwdriver moved the operating quadrant up/down to select gears. Got all 5 + neutral without a problem.

Took the inner cover off anyway, just to make sure there wasn't something screwy going on in there. Everything set up correctly. Inner cover back on, and checked with screwdriver again - all OK. Checked the outer cover mechanicals (gearchange quadrant, plungers, plate, etc) - the only thing I could find wrong was the bush holding the gearchange quadrant shaft was quite sloppy. On order.