Gearbox issue

[des hill]

I have a problem with my 2002 955i. On the overrun in 2nd gear, it feels like it is momentarily droping out of gear and re-engaging. On a long downhill, every second or so, it feels like it would if the clutch were pulled in and then re-engaged as a snap movement.

It seems fine under power, and I dont think the problem occurs in any other gear apart from second - which is why I think it may be the gearbox.

Has anyone else experienced something similar? Are there any other possible causes?

I have owned the bike from New, and it has done 50,000km

[Stretch]

If the bike popped out of gear (due to gear or synchro wear), it wouldn't pop back in by itself.  It would remain in neutral and you would have to clutch and put it back in gear.

How many miles are on the chain and sprockets?

Low RPM surge and a sloppy chain (driveline backlash)  can make the bike feel funny.

[des hill]

Yes - I tried tightening the chain first. No effect. I replaced the chain and sprockets last year and have only done 2000 - 3000 miles since then.

[iansoady]

I'd suggest surging as well. If you run on a steady throttle at about 2500 rpm does it surge then?

[des hill]

no. ITs fine on a steady throttle, or positive throttle. Its only a problem on a closed throttle on the overrun. The EMS is in fuel cut. If I pull in the clutch then the problem also goes away.

[2004Tiger]

It could be the computer playing with the fuel settings, trying to achieve lower emissions. Install the offroad tune and report back. An enquiring public wants to know.