Help needed with shimmy

[WillDV]

I've got some questions about a vibration I'm having in the front end. It starts at about 90km/h and continues to about 100km/h. I've heard alot about thrust arms being the problem here, but is there any way to tell the difference between it needing new thrust arms/bushings, or if it simply needs the wheels balanced? I've got the car scheduled for a balancing because I figure its a better idea to start with a 40$ wheel balance than a 300$ thrust arm replacement. My next question is how big of a job is it to replace the thrust arms/bushings? I'm not a complete idiot with a wrench and I think I've got all the tools I'll need, I'm just wondering though how long approximately it would take to replace the thrust arms, and if I'll need any special tools. I've had the car apart before, and then found out I need a tool that only the dealership has. Does anyone have any special tips/tricks that I should know about before I've got the car apart? If anyone who has done this remembers off hand what tools they needed, that would also help a whole lot.

[632 Regal]

Anything in "quotes" are searchable terms here: http://www.bimmernut.com/wwwboard/e34/si.html

while your in there for the balance, have them carefully check that the tires are round and the wheels are not bent. If they are aftermarket wheels you may need "hubcentric rings"

To do the thrust arms you need a GOOD "balljoint separator" torque wrench and a few wrenches, I forget what sizes (2-22mm,18mm?). After replacing mine what seems dozens of times I can swap them out in about 35 minutes a side, first time was a different story.

get lemforder thrust arms with the 750 bushings or the/M bushings, they last longer and are stiffer. BMAparts.com has these parts at a good price.

Any play in the steering linkage can give you the shimmy, even the "nut behind the wheel"

Anything in "quotes" are searchable terms here: http://www.bimmernut.com/wwwboard/e34/si.html

[stu1]

As Jeff says, searching is good and will work.

Having said that replacing the thrust arms is a moderately difficult job (I went through two separators doing mine and the third was bending before I got the blow torch out) - especially if they haven't been done before and everything's all shitty and rusted.

You will need to remove the struts and will need a decent torque wrench, 16mm spanner (for the swaybar links), 24, 22, 19mm spanners and sockets and then you have to get the old bushes out and the new in (hint: take them to a shop with a press )

Good luck!
Stu.

[632 Regal]

ahhhh...no need to remove the struts, no need to remove the sway bar links either. Thats what I thought when it took hours and hours. I dont even go under the car now, all done through the wheel well.

As Jeff says, searching is good and will work.

Having said that replacing the thrust arms is a moderately difficult job (I went through two separators doing mine and the third was bending before I got the blow torch out) - especially if they haven't been done before and everything's all shitty and rusted.

You will need to remove the struts and will need a decent torque wrench, 16mm spanner (for the swaybar links), 24, 22, 19mm spanners and sockets and then you have to get the old bushes out and the new in (hint: take them to a shop with a press )

Good luck!
Stu.

[stu1]

I'll try that next time Jeff (Although in my defence I was also changing the top bearings so I knew what state they were in).

I guess you just leave the strut dangling huh?

Stu.

[Claude]

I've got some questions about a vibration I'm having in the front end. It starts at about 90km/h and continues to about 100km/h. I've heard alot about thrust arms being the problem here, but is there any way to tell the difference between it needing new thrust arms/bushings, or if it simply needs the wheels balanced? I've got the car scheduled for a balancing because I figure its a better idea to start with a 40$ wheel balance than a 300$ thrust arm replacement. My next question is how big of a job is it to replace the thrust arms/bushings? I'm not a complete idiot with a wrench and I think I've got all the tools I'll need, I'm just wondering though how long approximately it would take to replace the thrust arms, and if I'll need any special tools. I've had the car apart before, and then found out I need a tool that only the dealership has. Does anyone have any special tips/tricks that I should know about before I've got the car apart? If anyone who has done this remembers off hand what tools they needed, that would also help a whole lot.

Check if you have a sticking caliper on one of your front wheels, that may be the cause of strong vibrations (that's what i've experience lately). Just jack the front of the car and check if you can easily rotate the wheels (if pad brake don't stick hard to the disc). If one is sticking one will generate much more heat on the rim than the other one (easy to check).

[WillDV]

ok thanks guys for your input, thankfully my dad does all his own repairs so I've got access to the tools I'll need (barring a hydraulic press ). I checked to see if its a sticking brake pad, but everything seems ok there, I had to reschedule the wheel balancing because of work, but if the wheel balance doesn't take care of this, I'll have to take a look at the thrust arms/bushings.

[fkong777]

in a nutshell of front end issue

1. Small vibration at 55-60 ...wheel balance or need of a hubcentric ring if wheel not OEM

2. vibration at braking 55-45 .... worn thrust arm bushing.

3. Violent Shaking vibration at 50mph braking or not... ball joint failure.

4. wondering steering .... alignment, worn tie rod or center link.

I dont know what a bad lower control arm will cause the car to do tho.

[sirius_GTO]

HMmmm. I am having shaking at decel and accel at 45-55. Even when im just cruising at 45-55 I will get violent shaking. So what can that be?

[stu1]

Too much caffeine?