Went over a pothole.
Ive got a mk5 gti golf. Gears 4 and 6 rattle like mad. But its easy to select. Neutral and other gears sound as though theres a bolt rattling around but they drive ok. Power is ok. Its 4th and 6th that sound like when you have your bmx with card hitting the spokes. Tapping clunk sound.
Update. The first gear jumps into reverse! And the clutch pedal vibrates.
Done some research and it turns out the input shaft runs the same gear for 4th and 6th. Which means its most likely the input shaft main bearing, perhaps the retaining clip has come loose, or the housing cover which pushes the retaining clip in has come loose or popped off? Its a high millage car so i reckon the gearbox case has been worn down where the input shaft bearing sits, and the input shaft is actually able to move about? Im aware you can buy shims. Has anybody done this before? Also think if the first gear jumps into reverse, and 4th n 6th rattle, could it be at all anything to do with the selecting tower? I.e. Can the selecting tower cut out guides fail, like for example hitting a pothole and the grove being bent out shape thus selecting multiple gears? Ive run the housing procedure for the gear selector and thats fine. The gears engage. Any thoughts?
