24 plate Fiesta ST gearchange worries

[nickyboy29]

24 plate, 1500 miles. Changing gear from 2nd to 3rd, it is catching on something metallic. It's the neutral to 3rd part that is catching.

Does not do it when downshifting from 4th to 3rd.

Doesn't do it when stationary with the engine running.

4th to 5th very slight catch but not as bad. All other gearchanges butter smooth.


Clutch to the floor.

Car booked in for the 26th.

I think it's been like this since new but i've not noticed as I put it down to maybe needs bedding in, plus I don't do many miles in it.

[GreenV8S]

Symptoms seem to suggest a synchro problem. Normally, a weak synchro would show up initially on downshifts rather than upshifts. However, I've heard of problems due to using a gear oil which is too thick when cold causing these symptoms because the viscous drag between the hub and the shaft prevents the hub from spinning down. I'd expect this to be gearbox design specific and I have no idea whether it would apply to your gearbox, but if it only happens at certain temperatures you might be looking at that sort of problem.

Renewing the gearbox oil with the correct spec might help and is unlikely to do any harm.