New thrust arm bushings still no help
 

I recently was having an issue with getting a hard tump/wheel shake when driving slow and coming to a complete stop (when I'm driving in a parking lot and suddenly see somebody coming out) I never had any type of vibration at any speed

I took it by a shop and was told I need to replace both trust arm bushings and ball joints so I did about 2 months ago and now I noticed the same feeling is back again

This is my first x5 and first bmw and I feel like this shop too advantage of me so I wanted to know what could be causing this so I know better when going back

How many miles on the X? What else suspension wise have you replaced? Besides from the thrust arm, have you replaced the Swing arm Control? Tension Strut? Get back to us. Also, please put your info in your signature auch as I have so we can ID your X faster.

107k i just got the car so i don't know what was changed. but the shop told me who ever owned the car before used quality parts underneath

2006 3.0

A few years ago I had similar - I thought I could feel what I considered excess movement when braking at slow speeds, but I never had any "normal driving" symptoms.

So one day I grabbed a dude from here at work and we went down to an empty parking lot (church parking lots are great for this stuff on a weekday), and I had him drive under 5 mph and then brake whilst I stood on one side, and then the other side. Sure enough, even though the bushings normally have some give, I could tell by eye that one front wheel tended to pull back under braking a little more than the other. Ordered up a pair of assemblies off rockauto. Made a nice difference. And of course with the old units out I could see that while not shredded, the bushings were not gonna hang in there.

Not reaching any particular conclusions on your specific situation, but I would consider a a parking lot test. Go real slow - slow enough you can follow the tire rotation, and that's all it takes since under braking any excess play will be visible.

Yeah, I concur with Civ. You will be able to see movement in those parts if they are worn.

As for the shop saying "They used Quality parts underneath" I dont know of anyone who can make that assessment just by looking at them. The bushings are sign tightly wedges within the assembly, how could one tell if they were from BMW or from Uro? Without taking them apart and looking at the stampings?

Thud on braking usually means a problem with the Tension strut, its the bigger one of the two arms on the hub assembly. Also the swing control arm controls lateral movement, if the joint is failing in those, you will be able to tell from sound.

i did that already thats how i knew i had a problem plus I did it when I went to the shop and they said its the thrust arm bushings and put it on the left and said the bushings was cracked

If it went away when you replaced the struts/bushings and now after a couple of hundred or thousand miles it is back, chances are the struts/bushings were cheaply made craps. Go with OEM or Powerflex bushings on OEM struts.

Since you are in the mile range where suspensions need to be rebuilt and you don't know the history of your X, I suggest you find a well recommended Indy shop and have them do a thorough inspection of your X, a post purchase inspection. If you can, stay while they do the inspection and ask them to show you how they know what needs to be addressed . That will give you a second in person opinion and get back to us with what they find. If the suspension needs other work it is better to have it torn down only once and be done with it.

it was replaced with oem

that's exactly what i did the first PPI said i needed just the thrust arm bushigs and wanted 750 then i went to a second shop and they said i needed the bushings and might as well change the ball joints and charged me 900 for all oem parts

:thumbup:

Since they were changed with OEM parts, I would go back to the shop that did the work and ask them to check it out as you have the same issue as before. Then do just what you did before except in reverse for the second opinion. No way that OEM bushing should fail this soon, I would be suspicious.

The bushing connection to the truck's frame needs to be tightened with the weigh of the truck on the tire. If the shop the tightened that connection with the truck on the hoist, that will leave to premature failure of the bushing.

x2 this!

x3

After only two months?

yes it can be that quick if bushing was torqued in air instead of with weight of car on it.

I have never torqued in the air so I don't know how big a mistake that is. How many miles do you think would have to be driven those two months?

If torqued in the air, the weight of the vehicle just stationary is stressing the bushings quite a bit. Driving would just add to the stress.

http://www.autohausaz.com/secure/Par...1121096372.jpg

That's one of the thrust arm bushings. The bolt that goes through the center and holds it to the frame also keeps that center metal insert in a fixed position; it doesn't rotate. The metal ring on the outside of the bushing is bound tightly to the thrust arm, and rotates with the up/down movement of the thrust arm as the vehicle moves over obstacles. The rubber connecting the center to the outside ring is designed to flex a bit, and allows up/down movement within a given range.

BUT... If the center of the thrust arm is torqued down without first loading the front suspension, the center starts out rotated down. When the vehicle is lowered to the ground and the weight of the vehicle is on that corner, the rubber will already be stretched almost to its designed limit. Thinking about that it's easy to see how the bushing will fail pretty rapidly.

One alternative I'm looking into is using spherical bearings instead of bushings. They are pretty widely used on other vehicles, especially offroad vehicles; one of the guys on the mye28.com developed a set for the e24, e28, e32 & e34, and has pretty good success with them. They do transmit a bit more road noise to the frame and cabin than OE bushings, but their longevity is much improved over OE, and replacing the wear parts is far easier than replacing the entire bushing. They also have a lot less flex than OE, so steering response is far improved as well. Since they are a spherical bearing instead of a rubber bushing, they don't require the suspension to be loaded before torquing down the center bolt.

Right now he's working on a variant that would fit the e53, which should also fit the e39 and a couple of other models. I'm thinking the pricing would be similar.

Moosehead Engineering Spherical Upper Control Arm Bushings

http://images.ecwid.com/images/525075/15262624.jpg

Oopsi, Meant I have always torqued in the air to be sure not to over stress the bushing and it says to do that in the manual. don't know how many miles it takes to destroy the bushings. What's the estimate?

any news on progress of these bearings for the X5? website doesn't list it yet.

I got an email from Paul at the end of August, and it sounds like he is getting close to having test pieces, but I haven't heard anything since. He's looking to verify the outside diameter of the e53 bushing; I put a cheapo plastic caliper on mine and it was about 2 5/8", but I'm not terribly confident in that number because of corrosion on the bushing and my measuring instrument. Paul says the e38 bushing is 66mm (2.59843"), which is in the ballpark of what I got. If anybody has a new bushing that they could put a caliper on, that would be immensely helpful.

Isn't it true that the E38, E39 and E53 all can share the same thrust arm bushing?

I remember on the M5 forums that people were using the X5 bushings before polyurethane ones came out.

I just ordered the Powerflex set. I can measure those next week...now if Paul needs a beta tester, I could wait to install the PF bushings... :)

FYI, E38/E39/E53 same size bushings, but different construction. See this thread on M5 forum.
X5 Thrust arm bushings - BMW M5 Forum and M6 Forums