DIY Article - How to Replace the Thrust Arms on your E39 540i - 56k No!

I just had lower control arms (and tie rods) replaced but still have a little shimmy. I am not at all sure whether lower control arms are the same as thrust arms. I did a complete front brake job (OEM rotors and Pagid pads) and was blaming un-even lug nut torque (or possible out-pf-round rotors) for the shimmy, which was less after an alignment.

I will also take this opportunity (I can hardly believe I'm doing this!) to give a thumbs-up to local dealer Critz. Reading the codes (to sort out a ABS thing that turned out to be a bad LR speed sensor) was only $65 and complete alignment was $129. After years of Critz=-bashing they seem to be coming around.

Rich

Originally Posted by Sonare

I just had lower control arms (and tie rods) replaced but still have a little shimmy. I am not at all sure whether lower control arms are the same as thrust arms. I did a complete front brake job (OEM rotors and Pagid pads) and was blaming un-even lug nut torque (or possible out-pf-round rotors) for the shimmy, which was less after an alignment.

Rich

I did mine recently and my control arm ball joint had some play in it as well. The thrust arm is the rear arm with a large bushing for the frame, and the other control arm is the front one that is tubular and straight.

Tips I can share from having done the thrust arms:

When tightening the ball joint nut, I suggest torqueing it down, back it off, then torque to spec again. The taper may otherwise throw off your torque value.
New BJ nuts are highly recommended, but thread lock can be used if you lose the new ones.
Use an allen key (8mm?) in the ball joint to keep it from spinning as you tighten it. If the spindle is under load (jacked up), this is not necessary.
To tighten down the bushing side of the arm, professionals will usually jack up that spindle to ride height and then torque it down.
Inspect the tie rods and front control arm for play after doing the thrust arm. Worn thrust arm bushings or ball joint can cause premature wear on those components. Have someone wiggle the wheel for you.
I suggest throwing in all new sway bar end links - they can get pretty loud for their size when they go bad.
You can grease the inside of the sway bar bushings with brake compound or other grease to mitigate squeaks down the road. Do not grease the bracket side of the bushings.

Harbor Freight is a good source for the 21-22mm wrenches ($15 for a full set up to 24mm), 21mm 1/2" socket ($3, 12-point is OK), and ball joint separator ($20). Ear plugs aren't a bad idea either

Not trying to derail the thread, but how can you tell exactly what the culprit is? As I mentioned-- I had the tie-rods and control arms replaced and also replaced the front rotors and pads with stock rotors and Pagid. After this I noticed slight shimmy when braking lightly form 70mph to 35mph. I suspect the rotors, but also suspect front shocks (there are 200k miles on these). The shimmy is getting more noticeable--

Rich

Rich, I wasn't trying to tell you what was causing your shimmy, just sharing my experience that may be causing it issues as well. Your symptoms can be caused by anything from poor wheel balance, tire cupping, rust on the hub causing the wheel to be mounted off-center (always sand it down and apply anti-seize), or any worn suspension component. I wouldn't put the shocks on the top of my list, but after 200k, you may be better of counting parts you can keep rather than parts to replace.

Have you tried wiggling a wheel and tire up/down and side to side? If there is freeplay, you should be able to pin point the (or a) culprit. Mine was the front ball joint on the driver's side, which requires a new control arm basically (pair). If you don't have any noticeable freeplay, it may be time to do a deeper inspection of the front bushings and joints using a pry bar.

Oh, and if you are able to detect the shimmy in the steering wheel, I recommend concentrating on the front;conversely, shimmy felt through the car seats and floor are more likely indicative of rear end vibration. Good luck and post back if you are able to narrow it down!

Ok someone help me out here just created an account to get a little assistance.. Ive just recently bought a 97 540i and just did a shtload of work already cause previous owner was brain dead i suppose. So I just replaced the rotors and pads in the front which ended the vibration at low speeds while braking.. Now after driving today I noticed the strong vibration at 50-60 while often having to over steering to the right while headed str8 (too loose?).. So I jacked the car up and the driver side wheel has a lot of play, not from top and bottom pressure but has lots of play from side to side (a lot of play actually)..

So ive read through this forum and with all the terms upper control, Lower arm, right upper, rear lower, thrust arm, traction strut, wishbone.. and theres actually more ive heard etc.. So when i look under at whats moving I see three main bars all of which are moving a bit under there, so which do I change first.. Is there 1 main arm that will prevent the whole assembly from moving around?? The one thing im clueless on with cars is this crap... thanks in advance for any help!

Originally Posted by PokerIzWork540

Ok someone help me out here just created an account to get a little assistance.. Ive just recently bought a 97 540i and just did a shtload of work already cause previous owner was brain dead i suppose. So I just replaced the rotors and pads in the front which ended the vibration at low speeds while braking.. Now after driving today I noticed the strong vibration at 50-60 while often having to over steering to the right while headed str8 (too loose?).. So I jacked the car up and the driver side wheel has a lot of play, not from top and bottom pressure but has lots of play from side to side (a lot of play actually)..

So ive read through this forum and with all the terms upper control, Lower arm, right upper, rear lower, thrust arm, traction strut, wishbone.. and theres actually more ive heard etc.. So when i look under at whats moving I see three main bars all of which are moving a bit under there, so which do I change first.. Is there 1 main arm that will prevent the whole assembly from moving around?? The one thing im clueless on with cars is this crap... thanks in advance for any help!

You need to step back and figure out which is the issue before you proceed. The movement you're describing can be due to any link down there.

Before we proceed, I should clarify the common names for those components..

Two aluminum bars, silver in color:
1. boomerang shaped one, closer to the back, mounted at 45 degrees to the car is the thrust arm. This one should also have a warning stickers about not hooking to it.
2. straight one in thefront, mounted perpendicularly to the car is the control arm, as they call it.

The last link you're seeing is part of the steering system, black in color (not aluminum), and should have some threads exposed. This is the outer tie rod.

The bad news is, they all wear and go bad. The good news is that you can figure out which by wiggling the wheel and looking for freeplay in a few key spots, essentially where the bushings and balljoints sit. This is easier with an assistant, obviously. The thrust arms also last about 60k miles so you may as well replace them anyway.

So take a look at where the freeplay is, then search around how to replace the part (always in pairs) because it isn't exactly straightforward. Popping the balljoints is a bit tricky, as is properly reinstalling the tie rods (count threads), bushings (torque under load), etc. There are a few very good DIYs here for all if those.

Thanks for the quick reply..

I pretty much see the thrust and control arms moving a bit.. So i guess i assume what ever has play all must be replaced? That last tie rod arm in the back is also moving.. So does this mean im suppose to buy 2 control arms, 2 thrusts, and 2 tie rods? I may just fix one side at a time this sounds expensive..

I read through the diy i have a pretty good idea what I've gotta do, just wasnt sure if either the thrust or control arm going loose would cause the other to move or not, like I said im clueless in this area... thanks again

Originally Posted by PokerIzWork540

Thanks for the quick reply..

I pretty much see the thrust and control arms moving a bit.. So i guess i assume what ever has play all must be replaced? That last tie rod arm in the back is also moving.. So does this mean im suppose to buy 2 control arms, 2 thrusts, and 2 tie rods? I may just fix one side at a time this sounds expensive..

I read through the diy i have a pretty good idea what I've gotta do, just wasnt sure if either the thrust or control arm going loose would cause the other to move or not, like I said im clueless in this area... thanks again

Check Amazon for decent prices on Lemforder parts, you can pretty much count on $110/arm and much less for the tie rods. There is no reason not to replace them in pairs, because if one side is bad then the other will soon go.. while chewing through your tires.

All play needs to be eliminated. With everything working as it should, you should have virtually 0 freeplay in your wheel tire assembly (aside from tire flex). This is well documented and you'll quickly see that it's best to replace it all, and always with GOOD parts. Going the cheap route, with fcp or similar, has shown to be a mistake on more than one occasion. I myself went with all Lem parts, threw in sway bar links, and left the tie rods alone because they were tight.

Cool, Ive had the arms in my amazon cart already was just waiting to figure out if I was actually going to have to purchase all of them..

How are the Beck Arnley arms? its weird when one brand says front upper left with bushing, while another says front right lower rear yet they're both the thrust arm.. geez

Also ive noticed how everyone says how hard it is to remove the ball joints, but no ones explained how to get them in, or what tool to use for that etc..

Originally Posted by Quick99Si

Check Amazon for decent prices on Lemforder parts, you can pretty much count on $110/arm and much less for the tie rods. There is no reason not to replace them in pairs, because if one side is bad then the other will soon go.. while chewing through your tires.

All play needs to be eliminated. With everything working as it should, you should have virtually 0 freeplay in your wheel tire assembly (aside from tire flex). This is well documented and you'll quickly see that it's best to replace it all, and always with GOOD parts. Going the cheap route, with fcp or similar, has shown to be a mistake on more than one occasion. I myself went with all Lem parts, threw in sway bar links, and left the tie rods alone because they were tight.

Actually found out (well think I did) that my issue is the tie rod end.. its busted wide open near the little boot.. it moves in and out of the housing its in as the wheel moves.. It actually looks to me like it causes a slight play in the other wheel as well..will be looking into how to go about replacing this part first...

My dad is saying the "drag link" needs to be replaced because its busted up.. not sure but also lookin into this..

Originally Posted by PokerIzWork540

Actually found out (well think I did) that my issue is the tie rod end.. its busted wide open near the little boot.. it moves in and out of the housing its in as the wheel moves.. It actually looks to me like it causes a slight play in the other wheel as well..will be looking into how to go about replacing this part first...

My dad is saying the "drag link" needs to be replaced because its busted up.. not sure but also lookin into this..

I just want to mention something about drag links (center links). I just replaced mine and it had no freeplay, but it did have a frozen ball joint which was not obvious until it was disassembled. The mechanic who worked on it said that he will now revise his advice to people that ask for front end inspections: You can try and shake the wheels and look for looseness in the linkage, but this type of problem won't be very evident until you disconnect the tie rods. Bottom line: Oem BMW steering linkage is not made to be greased, so you may also encounter frozen balljoints along with loose ones.

Thats some good info..thanks for that

I've now ordered the trw center link along with the left outer tie rod, and the Lem bushing for the idler arm.. My driver wheel has much play from left to right and the inner ball joint on the center link you can see it move in and out as the ball joint is ripped up.. The outer tie rod looks ripped as well..

My pass side wheel has a small amount of play in it also im hoping the idler arm bushing and center link take care of it.. Otherwise ill be looking into right tie rod and thrust arms after that..

Hopefully you or anyone really could help me with a question i have.. As I move the wheel left to ride (3 and 9 o'clock) would this mean its more likely a steering issue rather then a suspension bushing or ball joint? Is there any way to filter possible problem simple by observing a loose wheel from 3 and 9 vs 6 and 12 o'clock?

Thanks for the great DIY. Helped a lot this weekend, even though the job is very easy—good idea to get oriented.

FYI—I was able to change both thrust arms WITHOUT removing the pinch bolts and sliding the struts. Used an open end 22mm box wrench on the ball joint end of the thrust arms. Make the whole process a lot more easy.

That's interesting.. does your car have the sport package? For my 2000 540i/Sport, it was physically impossible to remove the bolt with the bottom of the shock in the way. Loosen and make a few turns, yes, but it was obstructed when trying to pull it out (I tried doing it without touching the shock, but then had to retighten and do like posted above)

Originally Posted by Quick99Si

That's interesting.. does your car have the sport package? For my 2000 540i/Sport, it was physically impossible to remove the bolt with the bottom of the shock in the way. Loosen and make a few turns, yes, but it was obstructed when trying to pull it out (I tried doing it without touching the shock, but then had to retighten and do like posted above)

Yes, I have the sport package. I should have mentioned that. 2001 540i/6 with sport package. Initially I loosened and made a few turns, and yes, with the ball joint completely in there, there won’t be enough room to remove the bolt. However, if you loosen the nut maybe half an inch or so, you give “some” room for the ball joint to move down. I actually loosened it enough to where the nut was just below “flush” with the top of the ball joint “bolt”, or stud, poking up through the knuckle. I then used my ball joint removal tool (the jaw with the threaded end from Harbor Freight everyone is mentioning) to pop out the ball joint (with a bang of course). The ball joint obviously did not completely come out, but it moved down enough to where I could continue to loosen the nut. Kept loosening, the nut fell right out, and out popped the ball joint from the knuckle, without ever having to touch the pinch bolts. I can’t imagine what a PITA it would be realigning that to keep ride height correct—I chose not to mess with that.

Originally Posted by Hotswimmer

HOW TO REPLACE THE THRUST ARMS ON YOUR E39 540I BMW

(1997-2003 5-SERIES V-8 CARS)

(... badass write-up ...)

Thank you for doing this detailed write-up and sharing it with us. I feel that even -I- can do this now!

Hey fellas,

Glad to see this thread is alive and well. Just thought I would also comment that I will unfortunately be performing this job again in a week or so. After about 2 years since posting my comments about this job, my cheapo Karlyn arms are causing severe shimmy when braking.

Interestingly enough, I get no shimmy/vibration at the steering wheel at any speed, but I do get it when braking. And yes, I have isolated the shimmy to the arms and not the rotors or pads.

Just wanted to put it out there. DON"T BUY KARLYN's or FCP or any Chinese made control or thrust arms! It's not worth it and you'll be replacing them within 2 years easily. This time, I'll be going with Lemfoerder OEM's currently 105 each at Pelican Parts.

Sadly, I also bought Karlyn control arms about 1 1/2 years ago, so if the shimmy issue isn't resolved by replacing the thrust arms, I'll be buying Lemfoerder controls arms soon too. Ugh!

I'm sorry to hear about your having to do your thrust arms again, but I really think it's worth repeating to stick with Mayle or Lemforder even if they cost 2-3X. The ideal solution, in my opinion, would be Mayle HD bushings as they seem to last longer than standard liquid filled bushings.

FWIW, I literally just finished replacing the control arms on my M3 no more than an hour ago. I went with Lems again because I'd rather not have to nervously wait for the deafening ball joint POP any time soon.

I recall paying $100/arm for the E39... The E46 ones run $250/arm, and they don't even come with a bushing! On the plus side, the ball joint separator saved my butt once again.

If anyone near Chicago needs help, I can lend you a hand with the job during the weekend. Whatever you do, make sure to preload the suspension as you torque the fasteners.

I'm new here...I just recently picked up a 2003 540i M Sport Titanium Silver with Black interior as a 'fun project' car and one of the thrust arm bushings was bad (driver's side). A little searching brought up this thread and it was very helpful. I ordered two brand new Lemforder thrust arms from Amazon for $240 shipped to my door. I had the luxury of being able to borrow my buddy's lift to do the work and went to it. I also used my air tools to make things quicker and a LOT easier. I followed the DIY instructions closely but did a few things differently. First of all, I did as nsogiba did and left the pinch bolt on the shock alone. There was no need go through that to get the ball joint off. I decided to use a fork type ball joint separator attached to my air hammer instead of the Harbor Freight tool and it took it out in no time...then just finished unscrewing the top nut and it fell right out. It's so much easier doing it this way BUT if you plan on reusing the ball joint then use the screw type puller instead. It won't destroy the ball joint. The last thing I did differently is use a jack to lift the wheel spindle just high enough to lift the car off the jack stand on that side to bring it to ride height then torqued down the bushing bolt as Quick99Si stated above in one of his posts. The whole job took me just over an hour to do and was a lot easier than I thought it would be. Yes, working under a lift has it's advantages and shortened the time it took to complete the job. Air tools obviously helped as well. The car drove pretty damn well before...now it's just like a new 540! Although, while checking things out before wrapping it up I found one of the sway bar end links had some play so it looks like I have another small front end job soon. I just have to wait for the OEM BMW part to show up.

Thanks to the OP for the great DIY.

JP

Does anyone know of a tool to remove and replace the thrust arm bushings on an e39 without removing the arms from the car (e.g. without using a hydraulic press). Thanks.

Thank you for taking the time to write a fantastic detailed description on this replacement and to have the pictures showing the parts helped so very much.

David

First off - GREAT thread!

Originally Posted by aa240sx

...Interestingly enough, I get no shimmy/vibration at the steering wheel at any speed, but I do get it when braking. And yes, I have isolated the shimmy to the arms and not the rotors or pads.

Ok guys I need some help. I too get a vibration in the steering wheel - but only when I am braking medium to hard - from high speeds 140 kph and down. The vibration can be felt in the steering wheel only when braking from the 140 kph down to about 80 kph it stops. Also when I am just about to come to a complete stop... it feels to me that the brakes are grabbing or are warped. But they are not! I have only used German made suspension parts! No cheap Chinese stuff on my ride.


some of the things I have replaced on the front suspension(new parts)...


thrust arm (Meyle)
control arm (Meyle)
outer tie rods (Meyle)
inner tie rod - middle (Meyle)
wheel bearings (SKF)
brake rotors and pads (ATE)

tires are new and balanced.


I suspect that the thrust arms I got did not have the HD bushings that a lot of guys talk about. I am thinking I should have BMW HD bushings pressed into my thrust arms.

Any words of wisdom?

Also check that your brake caliper mounting bolts are tight. I've had similar front end shimmy under braking twice because this has happened to both my left front and right front bolts. Feels just like warped brake rotors (or uneven brake pad deposition) and loose tie rod ends.

Originally Posted by banditman979

I am in the same boat as Bazzer......... any other ways of getting proper ride height without the weight??? and just to be clear I have a 525 the thrust arm is the straight arm towards the rear which has the ball joint entering up from the bottom into the knuckle correct?????? I know the differ from the 540....

Can anyone tell me exactly which hand tools are necessary here. I am going to need to buy some more sockets and open end wrenches I guess. Are the 16 mm and 18mm sockets really necessary here?

Originally Posted by Dackelone

First off - GREAT thread!





Ok guys I need some help. I too get a vibration in the steering wheel - but only when I am braking medium to hard - from high speeds 140 kph and down. The vibration can be felt in the steering wheel only when braking from the 140 kph down to about 80 kph it stops. Also when I am just about to come to a complete stop... it feels to me that the brakes are grabbing or are warped. But they are not! I have only used German made suspension parts! No cheap Chinese stuff on my ride.


some of the things I have replaced on the front suspension(new parts)...


thrust arm (Meyle)
control arm (Meyle)
outer tie rods (Meyle)
inner tie rod - middle (Meyle)
wheel bearings (SKF)
brake rotors and pads (ATE)

tires are new and balanced.


I suspect that the thrust arms I got did not have the HD bushings that a lot of guys talk about. I am thinking I should have BMW HD bushings pressed into my thrust arms.

Any words of wisdom?

I had the same problem when I replaced my front end suspension with aftermarket Meyle units. I will never use them again.

The vibration under medium to hard braking went away once I had my BMW install OE thrust arm bushings. They only charged me 110 euros for the install(+60 for the bushings)... so I let them do the job. I am so happy that vibration is gone now. Especially when driving on the Autobahn it was a real PITA when braking.

I am sold on using BMW only parts. I am so tire of doing the same job twice or three times bc of cheaply made parts.