GT6 GT6 Stiff Gear Selection

[Writer2022]

Hi guys,

I've got a GT6 MK3 1971. I was having clutch and gearshift issues. It was creeping forward with the clutch down and sometimes failed to engage at all. The car had a recent rebuild when I bought it, but I think a few problems had been missed, or began as a result of said rebuild. I replaced the clutch Master and Slave cylinder and bled it up. Seems fine now, but I haven't had it out on a run yet. This is because of the gearshift problems. I thought to begin with that the gearshifting issue was a result of the clutch (seemed sensible), but it's really quite stiff to get into gear and I get the ocassional scrape etc. I know it's not supposed to be perfect - it's 51 years old - but I know it should be smoother than that. I had to get the tunnel out the centre of the car to get to the slave cynlinder properly, and whilst it was off I noticed oil leaks on the gearbox. I took the side level bung out but I'm waiting for my oil to see how much was lost. I would have imagined it to dribble out a little at least, but it didn't. I also noticed some slightly loose bolts on the selector box at the top, so I'm guessing that this might have been where the oil was leaking from. Do you guys think that the stiffness in shifts could be just down to a low gearbox oil level, or are there some more sinister issues at play here?

Many thanks
Ian

 

[charlie74]

Oil level and type would be the easiest to check first. A proper gear oil works much better in mine than the 30 weight, non-detergent type that some recommend in our transmissions (I have a TR6 w/ overdrive). I tried running it once and could not get it into first on occasion and once i drained that and refilled with gear oil it was back to normal. You might want to drain and fill with whatever Triumph originally specified for the transmission but GL-5 is not good for our yellow metals. Find a GL-4 if you choose to do this.
good luck!

 

[TomMull]

Creeping forward with the clutch depressed is usually a clutch issue, not transmission. The difficulty in getting into first would go along with it. Air in the hydraulic system would cause the issue but it seems you've bled it properly. Wouldn't hurt to bleed it again.

Always exceptions of course and I certainly hope the gear oil change helps.

Tom

 

[Nobbster77]

if the clutch wasnt replaced completly you find that you have a mix of AP or Borg and Beck parts, the parts arent interchangeble so the chultch should be replaced with a kit . I had a mk2 where the cluch cover was AP and the plate B&B and it reallly didnt like changing gear , id also check the throw out sleeve to make sure its correct. The correct grade of gear oil is also essential as too viscous and gear changers can baulk in colder temps

steve

 

[Andrew Mace]

Hi guys,
... and whilst it was off I noticed oil leaks on the gearbox. I took the side level bung out but I'm waiting for my oil to see how much was lost. I would have imagined it to dribble out a little at least, but it didn't. I also noticed some slightly loose bolts on the selector box at the top, so I'm guessing that this might have been where the oil was leaking from. Do you guys think that the stiffness in shifts could be just down to a low gearbox oil level, or are there some more sinister issues at play here?

Many thanks
Ian

The only time oil woud "dribble" out the side fill plug is if the gearbox had been significantly overfilled; that side fill plug is a cheap-and-cheerful level gauge. That said, lack of sufficient oil could well be the cause of the stiffness.