So I fitted the AEN gearbox. I know sounds are difficult to diagnose unless heard yourself, but I'm going to try and ask advise anyhow. The box shifts 100%, clutch disengages completely, no noises from the box when accelerating through the gears or in neutral when the car is standing still and idling. The problem that I'm concerned about is when your driving and get of the gas and de-accelerating in gear against the engine there is a noise coming from the gearbox, sounds to me like some bearing, but not sure. You can only hear the noise when de-accelerating in gear. Anyone got an idea of what would cause something like this or what I could do to try and diagnose the fault.
Is there a way to determine which bearings it is that's starting to fail? Input or output shaft or diff?
I checked the gearbox oil level, had to top it up with about 200ml. Went for another drive to try and diagnose the problem more. When accelerating in any gear the sound is just audible, when de-accelerating in gear the sound is much more pronounced. Then when putting the it in neutral and letting the car free wheel the sound is less again. I've got a feeling it's a bearing issue, but would like to know which ones would be the most likely culprits considering the sound is much more pronounced on de-accelerating in gear.
Sounds like diff bearings, or even pinion shaft bearings gone and rattling the shaft about on overrun.
Hi, I had a recent noise like this, only happening when de-accelerating. I found that it was my down pipe on the exhaust!!! It was just touching the crossmember of the chassis where the exhaust had slightly dropped. This maybe something worth checking before hand???
So I decided to take out the gearbox for a better unit. Luckily the scrapyard where I bought it stuck to their word and gave me another one. The replacement gearbox is completely silent and I'm happy with the box. As I'm planning to open the gearbox soon to change the diff ratio I would also like to try and make the gearbox shift back easier from 2nd to 1st. With our gymkhana's we only use 1st and 2nd and thus the need to be able to easily shift back to 1st from 2nd. I need to be able to do this at about 40km/h. The gear linkages are all 100% adjusted as well as the clutch. Non of the gears grind on gear change. Just the 1st gear goes in very difficult. Will probably be replacing the syncro, but what else could be modified in the gearbox to make the change back easier? I've driven a car with a rally box and that thing falls back into 1st gear with no effort at all.
