Ok, this was probly covered in depth long ago, but, I'm new to BMW. What causes the shimmy in my 320i on braking. Only happens at speeds above 45 or so. Everything in the front seems to be good. Thx. Jim Jeffries
If it is on braking only, the likely cause would be warped brake rotors, unless you have some other issue that would cause uneven braking, such as a stuck caliper piston, although if the braking pressure being applied is uneven at the calipers, you would likely have a pull to one side or the other when braking. E21's are sensitive to wheel balance. The only way I could keep my 320i from having the annoying '55-mph-shimmy' was to have the wheels balanced on the car and, if they were removed for any reason, make sure they went back on aligned to the same bolt holes as when they were balanced. If you're not getting that non-braking shimmy, you're fortunate.
Brake Shimmy Thanks, Mike. I'll look at that. Not getting any pulsation thru the brake pedal. And the shimmy goes away as i slow down. It just that it's SOO much fun to drive fast on the mountain roads near my house. (When they are not on fire!!)
Sounds like you're getting the typical E21 shimmy which starts at higher speeds, as opposed to a braking issue. Besides on-the-car wheel balancing, everything else needs to be tight too - wear or deterioration in any bushings, bearings, or ball-joints might be a contributing factor, along with bent or out-of-round wheels. Replace your front wishbones if the ball-joints are worn; I don't know offhand if the bushings can be replaced separately - see: (start at the beginning for your production month, I chose late '82) http://www.realoem.com/bmw/showparts.do?model=1733&mospid=47175&btnr=31_0010&hg=31&fg=05 - 5, 6, 11 http://www.realoem.com/bmw/showparts.do?model=1733&mospid=47175&btnr=31_0073&hg=31&fg=10 -4 Wheel bearings also, plus steering-rack components http://www.realoem.com/bmw/showparts.do?model=1733&mospid=47175&btnr=32_0300&hg=32&fg=25 The swivels of the tie rods, and the tie-rod ball-joints Check for any slop in steering column u-joints/bushing (6, 8, 14) http://www.realoem.com/bmw/showparts.do?model=1733&mospid=47175&btnr=32_0342&hg=32&fg=30 Trying to eliminate the shimmy can be frustrating - my 320i was maintained to the nth degree and on-car balancing was the only consistent solution. Watch for rust - after 11 years of Ohio winters, my floorboards were one winter away from rusting through. Beware of snap-oversteer. If you are pushing the car in a turn and lift off the throttle, the back end can have a tendency to snap around on you in an instant. Same thing in low traction conditions. E21's are fun to drive, but reward (and almost demand) smoothness and proper driving technique. If you are going to drive it in snow, don't expect to get anyplace without a limited slip differential and snow tires. Otherwise - enjoy it! and actually, my name is Marshall
Thanks, Marshall This is good info, I will keep poking around next time I have it up on the lift. Proubly sounds like the bushings, (the car has 155,000 miles) Have already notices some of the snap understeer you mentioned ;-) Not much snow driving where I live ;-) Might be time to get new rotors also. Thx Jim
Jim, if you have BBS wheels, having them balanced takes away the shimmy. My '83 320is came with those wheels. It's not driven daily anymore, so sometimes I need to get the flat spot out of the tires first. For years, I complained about the shimmy that came about 50 mph, then went away at higher speeds. All I was told was that the wheels weren't meant for the car. Then I found a place closeby that fixed it by balancing the wheels correctly -- no problem. So it CAN be done!
