Am new to this board. Have 2003 325xi w/ manual 5 speed, about 6500 miles. Upshifts are silky smooth, but on downshifting I notice a very slight vibration when engaging clutch. The vibration does not last through the entire period of clutch engagement. Can't tell if it's coming from any of the driveshafts or the clutch itself. It's not really annoying, but for a new car it seems like it shouldn't be there. Haven't really noticed it until lately. Have been driving with manual transmissions for about 30 years and this is a bit rare. Also own a 1986 325es with 5 speed manual, 130,000 miles, but son is currently using it. When I purchased it, it had a slight vibration problem when driving at various speeds. Turned out I needed to replace one of the rear axle shafts which cleared up the problem. Any thoughts?
downshifting
- Thread starter tbone
- Start date
I don't usually match revs on downshift, mainly because I'm trying to use the engine as a brake. I do this a lot on all my vehicles, and never have any problems. However, I have noticed that I can minimize the vibration on my BMW if I do match revs.
Anyways, as an update, I am investigating this matter further from an engineering point of view, and have made some good progress in resolution of the issue. Hopefully in a few weeks I can report on the outcome. Unfortunately, I can not release any more info. than this at this time, as I do not want to adversely affect my communication link with my principle source of info. I do not want to raise expectations too far, but if/when I get this issue resolved, I will be happy to post some data that should be of use to others with the same problem.
Anyways, as an update, I am investigating this matter further from an engineering point of view, and have made some good progress in resolution of the issue. Hopefully in a few weeks I can report on the outcome. Unfortunately, I can not release any more info. than this at this time, as I do not want to adversely affect my communication link with my principle source of info. I do not want to raise expectations too far, but if/when I get this issue resolved, I will be happy to post some data that should be of use to others with the same problem.
It's your car and drive it the way you want, but...
Not matching revs going down the gears invites undue stress on the drivetrain and unneeded wear on the clutch face. Braking with the engine is OK (though brake pads are a lot cheaper than clutches etc.), but using the clutch face as a braking device invites failure. The vibrations you feel are nature's way of telling you that what you're doing ain't kool...
Not matching revs going down the gears invites undue stress on the drivetrain and unneeded wear on the clutch face. Braking with the engine is OK (though brake pads are a lot cheaper than clutches etc.), but using the clutch face as a braking device invites failure. The vibrations you feel are nature's way of telling you that what you're doing ain't kool...