Manual w202 pops out of 3rd Gear

[GrahamC230K]

1999 C230 Kompressor, manual, 98K miles.

Pops out of 3rd gear.

OK going up to 3rd and under load, but under light load, braking etc pops out of gear.

Mechanic thinks mounts are OK so problem is internal to the box.

Anyone else had this?

Any ideas?

 

[flyingtech55]

This used to be very common on older Leyland cars, Marinas, Dolomites etc. What happens is that when you engage each gear a spring loaded ball which goes into a pit (detent) holds the gear in engagment. Car gear boxes contain helical cut gear sets. This generates thrust: the thrust tends to pull the gears into engagement under drive and push the gears out of engagement on the over-run. This is the purpose of the ball and detent arrangement. It resists the torque and holds the ratio in engagement on the over-run. At high mileage the pit part of the arrangement wears and the torque is able to overcome thebreak out force and the gear jumps out of engagement. The cure is a gear box overhaul. Are you sure the car has less than 100K miles.

Gliderman

 

[GrahamC230K]

Are you sure the car has less than 100K miles.

Gliderman

Yes, had it since 40K, all genuine.

It gets driven though if you know what I mean.