Dear rec.autos.tech,
The Symptoms
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In the last two days, my Mitsubishi L300 van has suddenly developed a vibration/booming sound that comes from the back (the axle?), whenever I decelerate.
Yesterday it happened just once, when parking. Today it has rapidly developed to the point where it happens at the very slowest speeds. I only attempted 1st, 2nd and reverse gears, and it happens in all three. The problem goes away as soon as I push the clutch down. Sometimes the vibrations/booming can get pretty loud (when, say, suddenly taking my foot off the accelerator pedal) and I can feel that the van gets quite strongly braked as this happens. Scary.
I also note that now, as I change gear and pass through neutral, I can often feel gears "whirring" (vibrating) through the stick, at the neutral position. [I said that it's when I decelerate, but it's more like, when there's no "load" on the engine. I mean, when I go downhill, the vibrations start up, and I have to put down the clutch and use the brake until it levels out. When I go uphill (steadily), the vibration problem entirely goes away.]
The Thoughts
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I don't think it's the clutch. I think it's to do with the rear axle. Maybe I should replace the oil for the axle. (I've only just understood that it takes oil). Maybe the "play", the backlash of the back axle has gotten too big. I'm going to jack it up on it's rear axle tomorrow and run the engine, and see if I can't duplicate the problem when the back end's off the ground.
In the meantime, does anyone have any further advice?
With kind regards,
Sandy