A gearbox question

[Rob_R]

Just out of curiosity as my knowledge on this area in rather limited, but does moving the gear stick around in gate when the engine is off in any way damage or wear the gearbox internals?

I ask this as a friend of friend was told off by a sales person for doing this in an Audi showroom recently whilst sat in an R8.

The reason he gave was that the synchros get damaged because no oil is being receieved by the 'box when the engine is off and the car stationary.

Any truth in this?

[Snake the Sniper]

Whilst the synchro's need to be moving to do there job fully, the gearbox is a sealed unit. Well, sealed off from the engine anyway, so the oil is still there, just not being thrown about by the cogs. I would say it does no measurable harm.

[parody]

I can't see how it would do any damage, nothings moving and every things sat in oil. The only way you could do any damage is by trying to force it into a gear and snapping something like a selector fork but I doubt that's likely unless your mates with the Hulk!

[350Matt]

Potentially shifting without the clutch pedal pressed can cause some wear on the teeth of synchro cones as you're forcing the gear synchro against the immovable object of the engine. However being as they're made for taking up large speed differences of a few thousand RPM I very much doubt any wear would be measurable.

Matt

[GavinPearson]

There will be enough residual oil on the sliding elements to provide adequate lubrication for hundreds of showroom shifts. I don't think this is an issue.

The only issue you might get in a showroom is people trying to force a gear and bending a shift fork in the transmission, but you would need a lot of force to do that.