Wheel Shimmy Question

[SilverPuddle]

I have been tracking a wheel shimmy on my 1982 e21. I have rebuilt/replaced all the stock items in the front within the last year and it is still there.

Interesting though, I noticed that each changed moved the shimmy to a different speed and/or duration.

I noticed as I spun the wheel, the driver's side brake rotor touched the brake pad for approximately 1/3 of the rotation. I pushed the pads outward and went for a drive and it was better.

So now I am thinking, I may buy new rotors and see how that works.

Also, while I was under there, I noticed the front stabilizer connection to the control arm (wishbone?) looks to have a lot of space...is this correct? It has always looked strange to me...it doesn't look snug...lack of experience talking here.

IMG_3410.jpg


Anyway, any recommendation you may have are appreciated.

Thanks
"Shakey"

[jaredmac11]

Yea.. definitely time to start throwing in new rubber.

[onedroppr]

Eurometric control arm to sway bar poly bushing is a superb design, well upgrade to reduce shimmy.

Including new rack bushings, control arm bushings and everything aligned I totally got rid of the shimmy.

[SilverPuddle]

Thank you for the replies. Can you post pictures of what your upgrades look like?

I will get with Eurometric and order these parts.

1) e21 Late Outer Control Arm Bushings - Stage I
2) e21 Inner Control Arm Bushings - Stage I
3) e21 Front Sway Bar Bushings - Stage II

I do not understand the "Stage I, II, III", but I want to remain as close to stock as possible and remove the shimmy. This is my daily driver.

Also, did you buy NEW control arms and then install these bushings into these NEW control arms?

Thanks.

[320iAman]

That gap your seeing is why shimmy exists at speed as the hard rubber bushing 1/2 filled- starts to deteriorate-the front wheels start to bounce more , with full poly u there will be no gap and the wheels stay more locked to the surface,,you'll have a bumpy ride on non smooth road surfaces.

Randy

[SilverPuddle]

That gap your seeing is why shimmy exists at speed as the hard rubber bushing 1/2 filled- starts to deteriorate-the front wheels start to bounce more , with full poly u there will be no gap and the wheels stay more locked to the surface,,you'll have a bumpy ride on non smooth road surfaces.

Randy

Randy...if I can get a drive without the shimmy, I think I can take on the "bumpy ride". Is it bumpy because the flexibility is being removed from the system.

Have you heard of a "Super Flex" Ployurethane? I'm wondering if this is a hybrid between rubber and polyurethane?

http://www.superflex.co.uk/proddetai...od=SF091-0146K

Thanks.

[Manny G.]

Out of curiosity, are you running stock 13" wheels or upgraded wheel size?

[SilverPuddle]

Out of curiosity, are you running stock 13" wheels or upgraded wheel size?

Manny, I am running 15"x7", with a s stock offset of 14(?).

I have some stock 13" and 14" that I was going to put on the car to see if the shimmy was reduced. I really want to get this resolve, as it is the major issue that holds me back from using this car too much and I really like driving it.

[GDAus]

Have you heard of a "Super Flex" Ployurethane? I'm wondering if this is a hybrid between rubber and polyurethane?

http://www.superflex.co.uk/proddetai...od=SF091-0146K
Thanks.

umm .... "Super Flex" is just the name of the company

I've got their front anti roll bar bushes and bushes for the rear anti roll bar links on mine. Picked them up as NOS on ebay fairly cheaply. They made a big difference and are very well made ... fitted perfectly.

Their front anti-roll bar to control arm bushes seem to be a version of the OEM bushes with polyurethane subsituted for rubber and stainless steel hardware. These may provide a better compromise ride wise than full poly urethane bushes that are on offer elseware ?

Unfortunately, their site doesn't indicate what hardness compound they are using ... but the ones I am using on my front bar are harder than the standard rubber but haven't made the ride noticeably harsher or noisier. But they are quite expensive compared other brands!

Cheers

[Manny G.]

Manny, I am running 15"x7", with a s stock offset of 14(?).

I have some stock 13" and 14" that I was going to put on the car to see if the shimmy was reduced. I really want to get this resolve, as it is the major issue that holds me back from using this car too much and I really like driving it.

I've read of people not experiencing the shimmy with stock 13" wheels

[onedroppr]

I also recommend changing the rack bushings.

Be sure brake discs and pads are very straight and wheels balanced; that would make a big difference also.

[SilverPuddle]

This car is sucking me in (again), but I seem to like it.

I'm putting together the check list of things to check and parts to replace.

I recently replaced the steering rack bushings with rubber. I will let this be my last item to replace if needed.

I plan to check the bushings from superflex.
[http://www.superflex.co.uk/proddetai...od=SF091-0146K]

Thanks

[epmedia]

You also want to check the front subframe bolts. If they are loose, put some thread locker on them and torque to spec. They are easy to check, don't even have to jack the car up.

[320iAman]

You have to look at the hardness of the sway bar / control arm rubber bushings vs polyurethane for ride in the front , the hard rubber is close to 50 -60 A (shore hardness) and polyurethane starts at about 70 A and goes up to 90 A(racing) or there abouts. Generally with stock hard rubber bushings after a few years they have been flexed up and down enough times that they start to crack-so the press on the road surface has gone down enough so that the wheels will vibrate at 55 mph or so.

You can knock out the bushings with a 30 mm socket and install new ones and keep that softer ride or can stuff in some hard hard rubber--round plug cut to fit to keep the vibration down or inject 50- 55 A polyurethane into gap-this has been done with other models and people whom have done this have touted its keeps the vibration out or install polyurethane bushings, polyurethane steering rack bushings- keep the vibration contribution down also yet do nothing for the control arm contribution to vibration from older wore hard rubber control arm bushings.

Another source of vibration overlooked is from the ball joint area of the control arms, these ball joints ride in a hard plastic cup---put in to get rid of zerk fittings and keep the car off the lube rack-when this hard plastic has wore down a very small gap will exist and as the grease is pushed aside--vibration will exist there as well, when too much of a gap is there you'll hear a clunk going over bumps at very low speed, at this point the control arms are beyond good and need to be replaced.


I have a project I have put off to deal with sway bar / control arm bushing vibration, I have all items.

Randy