Vixen 2500 - gear change problem
Discussion
Suddenly got a problem changing gear in my 71, 2500 Vixen fitted with Triumph gearbox and ‘A’ type overdrive unit.
Problem going from 3rd to 2nd as I approached a roundabout and then realised that I could not find any gears – at least for a few seconds until finally got back into third and carried on.
Continued the journey and found all gears difficult to get, but esp first at junctions. Assumed clutch may not be fully disengaging.
Checked clutch slave and rod and I have a good inch or more rod movement. Bled system – no air and no apparent issue. I seem to have clutch action and disengagement eg. in gear on sloping driveway car rolls back quickly when clutch depressed.
Went for another test drive after bleeding clutch system. Got reverse off drive, got first but could not get second. Found reverse – turned round – back on drive.
Bah ! lets give it another go.
Next attempt more successful – out of village got through gears and up into 4th – on slowing down got 3rd but could not get second.
Stopped – found 1st gear but 2nd difficult to locate – but managed to drive off.
Next junction found it difficult to get 1st – but did eventually.
Homeward bound could not get from 3rd to 2nd around tight corner
Back on drive stationary all gears difficult to locate.
Checked gear lever – spring and plunger ok. Loosen adjuster pins.
Another test drive – could not get into second gear. Abandon test drive. Found reverse – then first and back on driveway.
No previous issue with gearbox or overdrive.
Recon gearbox and OD unit – 1500 miles done
New clutch master cylinder/pipe/slave cylinder – no leaks and good action.
Clutch cover was the only part not renewed.
Any suggestions ?
Problem going from 3rd to 2nd as I approached a roundabout and then realised that I could not find any gears – at least for a few seconds until finally got back into third and carried on.
Continued the journey and found all gears difficult to get, but esp first at junctions. Assumed clutch may not be fully disengaging.
Checked clutch slave and rod and I have a good inch or more rod movement. Bled system – no air and no apparent issue. I seem to have clutch action and disengagement eg. in gear on sloping driveway car rolls back quickly when clutch depressed.
Went for another test drive after bleeding clutch system. Got reverse off drive, got first but could not get second. Found reverse – turned round – back on drive.
Bah ! lets give it another go.
Next attempt more successful – out of village got through gears and up into 4th – on slowing down got 3rd but could not get second.
Stopped – found 1st gear but 2nd difficult to locate – but managed to drive off.
Next junction found it difficult to get 1st – but did eventually.
Homeward bound could not get from 3rd to 2nd around tight corner
Back on drive stationary all gears difficult to locate.
Checked gear lever – spring and plunger ok. Loosen adjuster pins.
Another test drive – could not get into second gear. Abandon test drive. Found reverse – then first and back on driveway.
No previous issue with gearbox or overdrive.
Recon gearbox and OD unit – 1500 miles done
New clutch master cylinder/pipe/slave cylinder – no leaks and good action.
Clutch cover was the only part not renewed.
Any suggestions ?
Thanks for the advice. Have done some more testing and to sum up the latest is:
Gear selection is fine with engine not running.
Gear selection is almost fine with engine running on tick over – but second is sometimes difficult.
External clutch operating parts seems fine, ie Lever arm starting position vertical and then good movement on slave push rod to move lever arm.
With rear wheels jacked up off ground clutch disengagement checked and there appears to be plenty of it, and no drag.
Cannot detect crankshaft end float.
Gear oil changed and no nasty bits seen.
My last test drive found one consistent scenario:
Third a bit sticky to get out of and then rarely possible to get down into second but can get back into third, or clutch down, virtually stop the car, select first and then you can go up into second, third and into fourth.
Occasionally when third to second is actually achieved there can be gnashing of gear teeth.
Methinks that the gearbox will have to come out and hopefully the problem will be seen, be box related eg synchromesh, selector forks or even a clutch related issue.
Gear selection is fine with engine not running.
Gear selection is almost fine with engine running on tick over – but second is sometimes difficult.
External clutch operating parts seems fine, ie Lever arm starting position vertical and then good movement on slave push rod to move lever arm.
With rear wheels jacked up off ground clutch disengagement checked and there appears to be plenty of it, and no drag.
Cannot detect crankshaft end float.
Gear oil changed and no nasty bits seen.
My last test drive found one consistent scenario:
Third a bit sticky to get out of and then rarely possible to get down into second but can get back into third, or clutch down, virtually stop the car, select first and then you can go up into second, third and into fourth.
Occasionally when third to second is actually achieved there can be gnashing of gear teeth.
Methinks that the gearbox will have to come out and hopefully the problem will be seen, be box related eg synchromesh, selector forks or even a clutch related issue.
After being side tracked onto easier and more productive projects I have finally got back to the Vixen 2500 and removed the engine and gearbox.
The gearshift problem seems to lay with the shafts in the top cover and the interlock mechanism. Comparing with another Triumph gearbox top cover for which all selector rod movements are smooth with an obvious feel of the ball bearings dropping into their detent, my troublesome top cover is stiff, or just non-compliant especially on one/two and reverse.
Will have to dismantle and inspect but first I have to get those tapered wedglock screws out of the selector forks/shafts. They are very tight !
The gearshift problem seems to lay with the shafts in the top cover and the interlock mechanism. Comparing with another Triumph gearbox top cover for which all selector rod movements are smooth with an obvious feel of the ball bearings dropping into their detent, my troublesome top cover is stiff, or just non-compliant especially on one/two and reverse.
Will have to dismantle and inspect but first I have to get those tapered wedglock screws out of the selector forks/shafts. They are very tight !
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