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I have 1998 Nissan Avenir Station Wagon with a manual gearbox. It has travelled about 125,000k's.

When driving in 2nd gear it sometime just 'pops' out with a loud grinding noise when driving.

This is almost always when changing down. Is this likely to be an adjustment or a replacement fix?

David

From the "Ask Jack" archives - 30 September, 2010

While a check of the linkage is the first step I suspect the problem is internal and the gearbox will need to be removed/dismantled.

When a gear is selected a freewheeling gear (say 2nd in your case) is matched by way of a sliding hub with a fixed gear connected to the output side of the gearbox.

The noise you are hearing is probably the freewheeling gear grinding against the mating teeth on the sliding hub as it disconnects or “pops” out of gear. The reason for the disconnect is probably due to wear on the gears/sliding hub or the selector fork which is basically an extension of the gearlever.

One of the issues with this sort of fault is there will be other wear and tear in the gearbox which will drive the repair costs up. It would be highly recommended to check the clutch assembly for wear also while the transmission is out of the vehicle.

You need to talk to your repairer about the options available to you. For a car of this age a second-hand transmission may be a consideration but I would want to know an estimate to repair your transmission verse the cost of a second-hand gearbox first.

Anything second-hand can have its risks.

You also need to be very clear on the guarantees the repairer offers on the various options.