I can heard a distinct rumbling sound when idling in neutral which I presume is coming from my OD gearbox. The sound stops when I depress the clutch which I guess confirms it's a gearbox bearing, probably the front. The sound stops because the gearbox stops. I guess I'm looking for confirmation of my diagnosis and whether I should be overly concerned and replace this bearing ASAP or is it likely to be a mere annoyance until I can 'get around to it'.
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Enjoy.
Rumbling sound from my gearbox
- Thread starter mattinoz
- Start date
RootesRich
Donation Time
Could be the throw out bearing. I had the exact same situation as you described. Upon pulling the tranny I discovered a lightly worn carbon throw out bearing missing a few pieces.
puff4
Platinum Level Sponsor
There are only three bearings that are active with the clutch released and the gearbox in neutral - the input shaft bearing, the mainshaft needle bearing and the layshaft needle bearings.
The sound you hear is almost certainly the front input shaft bearing, a roller-ball bearing, which will nearly always make a low, rumbling sound when it's going duff. The needle bearings don't make much noise as they fail... they just gall the shafts and sockets until the mainshaft/input shaft flex begins to cause the transmission to pop out of gear.
The sound you hear is almost certainly the front input shaft bearing, a roller-ball bearing, which will nearly always make a low, rumbling sound when it's going duff. The needle bearings don't make much noise as they fail... they just gall the shafts and sockets until the mainshaft/input shaft flex begins to cause the transmission to pop out of gear.
RootesRich
Donation Time
Take it from my experience that a broken carbon throwout bearing makes plenty of noise when not in contact with the pressure plate.
Ok so I got 2 possible candidates for this noise both of which require dropping the tranny. So replacing both would be the prudent thing to do. The throwout bearing obviously is the easiest of the 2. Replacing the main bearing requires what? Dismantling the innards or does it come out from the front? Is it a job for a professional? I presume it will need some kind of press to get the bearing off the shaft?
