27-09-2019, 10:49 PM
Thanks for the ideas:-
Mike - I am fairly confident it is not the clutch thrust bearing as it not spinning when the noise occurs - I have checked on both gearboxes that it is not moving when you can hear the noise.
Ian - when driving the engine noise drowns out the gearbox noise so I can't be sure if it is better or worse under load.
Modified to close ratio gearbox - it is possible the after market gears were badly cut but I don't think wear is the problem as it has always been noisy. I replaced the 1st, 3rd motion and inter shaft bearings on this box and it made no difference. This box is in a car so I could check if the noise is better or worse in different gears by jacking up the rear axle.
Original close ratio gearbox - this is connected to an engine on a test bed. The 1st motion shaft and inter shaft bearings are smooth and shows no sign of wear. The gears do not seem worn to me but I am not an expert. I could try this box in different gears but not under load.
Mike - I am fairly confident it is not the clutch thrust bearing as it not spinning when the noise occurs - I have checked on both gearboxes that it is not moving when you can hear the noise.
Ian - when driving the engine noise drowns out the gearbox noise so I can't be sure if it is better or worse under load.
Modified to close ratio gearbox - it is possible the after market gears were badly cut but I don't think wear is the problem as it has always been noisy. I replaced the 1st, 3rd motion and inter shaft bearings on this box and it made no difference. This box is in a car so I could check if the noise is better or worse in different gears by jacking up the rear axle.
Original close ratio gearbox - this is connected to an engine on a test bed. The 1st motion shaft and inter shaft bearings are smooth and shows no sign of wear. The gears do not seem worn to me but I am not an expert. I could try this box in different gears but not under load.