Shift points

[Zchild]

Hello Gearheads and Bimmer dreamers, I need some information concerning shift points and BMW manual transmissions. I recently began having problems when I shift between 2,500 and 3,000 RPM's. I get a slight grinding sound from the rear whells and it seems as if my wheels are trying to spin faster than allowed. When I shift at higher RPM's, say 3,000 to 4,000 I don't get the studdering action and my shift is smoother. The higher shift envelope brings more speed and thus propels the car up into the 80/90 MPH area quickly. I don't need any more tickets, therefore, I'm trying to figure what's the best for the transmission, clutch as well as optimize my shift points. Thanks in advance...

[slantsixm3]

Z-
You have a pretty wide latitude with regard to shift points without hurting the car's mechanicals. Just whatever you do, do it smoothly. You can shift from 2000 to 6000 rpm without causing any significant harm, just a bunch of noise and wasted gas at the higher levels.
If you are hearing a specific noise when shifting at 2500-3000 rpms, this may warrant investigation, the car should shift smoothly at those speeds, and there should not be any problems from the back of the car.
More likely options are a mild clutch chatter, a common problem with older E36s, and maybe some loose bushings or driveshaft bearing in the rear, if that's where the noise really is. I'd get a mechanic to ride with you and try to reproduce the noise, to be sure about the source.
Good luck, let us know how it goes.