Gearbox issues
Discussion
The gearbox on my Mk1 Tuscan has never been the smoothest of operators, always a bit notchy, reverse is achieved by the well known into 5th first then straight back to reverse method. Now it has developed another habit....
Stationary with the engine running and the clutch depressed it will not go into 5th or reverse without serious scrunching, in reality it will not actually go into gear. Pumping the clutch makes no difference.
Stationary with the engine off it still wont go into 5th.
When driving along it is ok.
The problem may be temperature related as it seems worse at the end of a journey.
Any ideas?
Stationary with the engine running and the clutch depressed it will not go into 5th or reverse without serious scrunching, in reality it will not actually go into gear. Pumping the clutch makes no difference.
Stationary with the engine off it still wont go into 5th.
When driving along it is ok.
The problem may be temperature related as it seems worse at the end of a journey.
Any ideas?
Don't know if this is a good idea or not, but worked a treat for me... Try screwing the rubber clutch stop in as tight as possible. I think mine had managed to undo itself causing reduced clutch travel. However, I was told that giving yourself too much travel may put stress on the clutch fingers causing them to eventually snap.
Every other gear works ok. Not as smooth as your modern massed produced tin can but it all works. Even driving it and using gear shifts at 3 or 4,000 rpm are no issue.
I am talking purely zero forward speed and engine running. It just graunches into 5th or reverse. (Forget reverse that is a known problem on all T5's)
There are cogs still turning in the box, clutch down, that do not mesh with the gear selection. If I were moving I would say it is syncromesh issues, but I am not moving.
Stationary and engine off it will still not select 5th!
I am talking purely zero forward speed and engine running. It just graunches into 5th or reverse. (Forget reverse that is a known problem on all T5's)
There are cogs still turning in the box, clutch down, that do not mesh with the gear selection. If I were moving I would say it is syncromesh issues, but I am not moving.
Stationary and engine off it will still not select 5th!
The synchro on fifth in a t5 is not robust. It is a weak point.
From stationary put it into third, fourth, and then fifth to stop the box spinning. Mine does it. Two track days later it still does it. It sounds like your not stopping the motion in the box.
If it isn't this it will likely be the clutch.
There are no finger followers... Just a diaphragm spring consisting of fingers.
From stationary put it into third, fourth, and then fifth to stop the box spinning. Mine does it. Two track days later it still does it. It sounds like your not stopping the motion in the box.
If it isn't this it will likely be the clutch.
There are no finger followers... Just a diaphragm spring consisting of fingers.
Ok with the car stationary and the clutch fully depressed nothing should be turning in the box. This means the clutch is not fully disengaging. My local TVR garage suggested pedal travel adjustment. So I have tightened the screw on the floor a couple of turns and things seem easier but not fully cured. Taking advice from an above posting is it wise to increase the pedal travel further and risk snapping the fork? I still have a lot of adjustment left before it is fully in. Its definitely worse when hot. Does hydraulic fluid lose its property when hot?
Edited in light of the response below. I have my fork and fingers mixed up (could explain my difficulty with eating food as well)
Edited in light of the response below. I have my fork and fingers mixed up (could explain my difficulty with eating food as well)
Edited by scruggs on Saturday 13th July 20:12
scruggs said:
Ok with the car stationary and the clutch fully depressed nothing should be turning in the box. This means the clutch is not fully disengaging. My local TVR garage suggested pedal travel adjustment. So I have tightened the screw on the floor a couple of turns and things seem easier but not fully cured. Taking advice from an above posting is it wise to increase the pedal travel further and risk snapping the fork? I still have a lot of adjustment left before it is fully in. Its definitely worse when hot. Does hydraulic fluid lose its property when hot?
You would have to press really hard to bend the clutch release fork....... there isn't one. The slave is a centrally mounted oneOk with the car stationary and the clutch fully depressed nothing should be turning in the box. This means the clutch is not fully disengaging. My local TVR garage suggested pedal travel adjustment. So I have tightened the screw on the floor a couple of turns and things seem easier but not fully cured. Taking advice from an above posting is it wise to increase the pedal travel further and risk snapping the fork? I still have a lot of adjustment left before it is fully in. Its definitely worse when hot. Does hydraulic fluid lose its property when hot?
The car has done 31,000 miles (round figures). The history has a hole in it for about 3 years (around 27,000 miles) and there is no documentary evidence of a clutch replacement. So it could be the original clutch. The biting point is still good at around mid pedal travel and no vibration or other signs of friction surface contamination.
The slave cylinder was changed last year at 29,500 miles with no reports of other issues by the TVR specialist at that time.
The high ambient temperatures in the south east of England at the moment seem to coincide with this problem so maybe high gearbox oil temps are an issue.
Took it for a run today after adjusting the pedal travel and at 5 miles travelled the box worked great. after 10 miles it was back to graunching a bit when stationary and selecting 5th prior to reverse. (need to reverse into parking)
When driving it works fine which would suggest the syncro is good.
The slave cylinder was changed last year at 29,500 miles with no reports of other issues by the TVR specialist at that time.
The high ambient temperatures in the south east of England at the moment seem to coincide with this problem so maybe high gearbox oil temps are an issue.
Took it for a run today after adjusting the pedal travel and at 5 miles travelled the box worked great. after 10 miles it was back to graunching a bit when stationary and selecting 5th prior to reverse. (need to reverse into parking)
When driving it works fine which would suggest the syncro is good.
Mine was definitely stiff before I had my clutch and slave cylinder changed.
Albeit after 1000 miles on a hot day like yesterday it is still not a smooth change like a modern car.
On my Chim I had a big change in clutch performance after a fluid change, they must have done this when they changed your slave ??
There is a remote bleed under the air box. Its a two man job though. I had a look at my old clutch when it came out and you could see signs of finger deterioration and general wear. I did adjust the stop on mine before I finally gave in to a clutch replacement.
Albeit after 1000 miles on a hot day like yesterday it is still not a smooth change like a modern car.
On my Chim I had a big change in clutch performance after a fluid change, they must have done this when they changed your slave ??
There is a remote bleed under the air box. Its a two man job though. I had a look at my old clutch when it came out and you could see signs of finger deterioration and general wear. I did adjust the stop on mine before I finally gave in to a clutch replacement.
scruggs said:
The slave cylinder was changed last year at 29,500 miles with no reports of other issues by the TVR specialist at that time.
If the clutch action feels notchy, then the slave cylinder has failed again, there are some sub-standard seals doing the rounds at the moment (mine failed after 1000 miles!) but if the action is smooth, what you describe sounds like a plate failure. I'm a little surprised that your specialist didn't recommend a plate when they replaced the slave cylinder. The plates tend to last 25-30k miles so it would have been due when the slave was done, did they not even recommend a new plate at the time?
Paul
Ok guys thanks for your learned input. It would seem most likely that the fingers are wearing out and that this can be compensated for slightly in the short term by adjusting the pedal travel. Eventually the clutch will have to be replaced.
The suggested method of changing through 3rd, 4th and then into 5th worked this morning. So I am going to live with it for a bit longer.
Regards
Pete (Scruggs)
The suggested method of changing through 3rd, 4th and then into 5th worked this morning. So I am going to live with it for a bit longer.
Regards
Pete (Scruggs)
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