Replaced front bushings with Powerflex - Need help identifying a vibration/wobble
 

Folks, recently replaced both front control/thrust arm bushings with the PowerFlex options along with the balljoint with the oem option. The replacements definitely took care of the sudden play when hitting the brakes.
However, noticing a light wobble in the steering wheel at certain speeds; but more importantly, when going over a bump at mid-high speeds (40+ mph), a much more severe/vibrant shake is felt on the steering wheel.
Any thoughts/ideas as to what this could be?

Well, the main reason the OEM bushing was designed the way it is would be to absorb some of the impact on the steering/suspension during driving. It is kinda like a small shock absorber built onto the thrust arm.

The solid polyurethane bushings transmit all of the feel from the bump through the steering straight to the steering wheel. That is one of the given side affects of the poly bushings.

For the slight shake while driving, it most likely was always there but you couldn't feel it with the OEM bushings. It is most likely caused by wheel balance and may be worth having your front wheels road force balanced. (and make sure they actually road force balance, tell them you want the before and after printouts for each wheel)

NineKrpm,

Did you do the job yourself, or have it done professionally? We're in the process on making an offer on a pristine 2003 X5 4.4, and the pre-purchase inspection revealed that the only major item needing attention is the thrust rod (aka lower control arm) bushings, so I'd like to see if this is a job I could tackle myself and save some money. If you did it yourself, could you please describe the process?Or is there a procedure posted somewhere on this site? I've been searching, but haven't found anything yet. Thanks.

A member named X5Girl posted a great thread with writeup and many pics on changing the bushings over to polyurethane, but you will need a way to press the bushings out/in.

also anytime you do suspension work its a good idea to get an alignment. That could easily cause pulling or a wobble at speed.

:iagree: This is a very common complaint with the poly bushings on road cars. Save the poly for track cars, imo.

+1 on this.

Thanks for the feedback folks. I am going to revert back to OEM, but in steps. Next week I will replace the pull-rod bushing (number 7) with a new OEM piece. This piece seemed to have the most space built in to the bushing to allow it absorb the bumps and reduce the wobble. Assmuming it does or does not remedy the issue, I will replace the front arm bushing as well with an OEM piece.

Keep you guys posted.




http://www.realoem.com/bmw/diagrams/f/b/193.png

I did have my alignment checked as well and adjusted with minor changes; that did not solve the problem.

The must be due to the harder bushings.

Well, when you go back with OEM clean up those poly bushings and I'd might be interested. Since I have free access to the tire balancer and alignment machines I should be able to keep the wobble out, and I might as well try them out since I'm about due for bushings anyways :D

PM me if that's an option and we'll discuss price.

Well, we went ahead and bought that 2003 X5 4.4i. We had a PPI done by a BMW specialist, and the only problems he found was leaking valve cover gaskets, and worn thrust rod bushings (aka upper control arm bushings, front control arm bushings, pull-rod bushings, and who knows how many other things it's called :dunno:). It's defintiely #7 in the above diagram, though. So, the car's a real gem - looks brand new, inside and out.

So, looking at the thrust rod (I'll just call it that to keep it simple), it looks very easy to remove, as it's totally accessible. And yet, the quote calls for something like three hours labor, so it can't be that simple. I've done a lot of work on cars in my life, but not a whole lot of suspension work in the last few years. My plan is to remove the thrust rods, and take them to a machine shop to have the new bushings pressed in. What's the trick or tricks to taking the thrust rod out? What kind of tools are needed? Since the ball joints are OK, it seems like the easiest thing would be to remove the two #16 bolts that appear to attach the ball joint to the frame, and then remove the #8 bolt that holds the thrust rod at the bushing end, and drop the thrust rod out. This just seems way too easy. What am I missing? Thanks!

Oh, and in case anybody is wondering what I mean by "Multibeemer," the X5 makes three in our family - a 2007 328i that I picked up for my wife through a European delivery, a 2004 325i that we recently bought for our daughter, and now the X5. And I have a 1992 Porsche 968 that I like to take to the track. I guess we kind of have a thing for German cars :thumbup:

Keep in mind that you can replace the OE fluid filled thrust rod bushings with non-fluid filled heavy duty ones from Meyle (non-poly bushings). I had this done on my X when my new OE bushings failed after about 30k miles. So far so good with the heavy duty units. Only have about 10-20k on them so far.

I just did this myself with the help of a friend who has a shop with a lift. Your description of the repair is right on, thats it. I replaced the ball joint myself and would recommend the same for you since you already have it off. If you do the ball joint you may want to separate it from the arm before loosening the screws for the ball joint. A good smack with a hammer in the right spot will loosen the arm from the ball joint. Also the ball joints use a star shaped socket, but we just used a regular socket just fine.

Then had a shop with a press remove and install new bushings.

I didn't see those before and think they would more suit my liking, but couldn't find them actually for sale online just now... Found them on Meyle's site at least.

Where did you get them from? Can you give me a link?

They are hard to find online. I found them here just now.

https://eactuning.com/hd-control-arm...-x5-p-446.html

I think Bimmerworld and BavAuto may carry them.

My independent mechanic recommended and installed mine. I had not heard of them before.

Thanks, bookmarked link for future use. :D

No problem. Glad I can actually help you out for a change. Even if it is in a minor way. If you get them or find them elsewhere, let me know and definitely let me know what you think after you get your hands on them.

No problem!

The BMW specialist who did my PPI also recommended the Melye thrust rod bushings. I also had to search quite a bit to find them, but I finally found them at www.autohausaz.com. They're part number 31 12 6769 715. Visually, mine actually look like they're not in bad shape, but both the BMW dealer where the car was serviced, and the mechanic who did the PPI, recommended replacing them, so I'm going to go ahead and do it. He said the rest of the front suspension (rear/lower control arm bushings, ball joints, etc.) are all in good shape, though, which I'm very pleased with in a 7-year-old car.

Does anyone know the torque specs on the pertinent bolts holding the thrust rod? Thanks.

I am up for this; will keep you posted!!! Working on swapping them out on thursday and taking the car in for an alignment (same day) as well.

Make sure the x is on it's shoes and loaded before tightening thrust, control arm bushings and swaybar bushings. Without doing this will cause vibration

Unfortunately I think I changed my mind when I learned of a middle of the road option of the meyle rubber bushings. Stiffer than OEM with more give than powerflex.

But I'm sure you'll have no problems selling them through the forum though.

problem fixed by replacing the thrustrod bushing (#7). car is back to normal.

although braking was better with the powerflex bushing vs oem; but I guess I will compensate that for proper steering feel.

Does anyone know the torque specs for the bolt going throughthe middle of the thrust rod bushing, and the two small bolts that hold the ball joint at the opposite end of the rod to the frame? They're items 8 and 16 in the diagram in post #8 of this thread. Thanks.

Pretty fookin tight on the ball joint ones (just be extra sure not to round off the heads!) and really fookin tight on the big one through the bushing (just be sure to have the X sitting at ride height/on her wheels before tightening it)

So are we talkin' lug nut level tightness, or even tighter? The bolts holding the ball joints to the frame aren't all that big, so I'm surprised they need to/can be tightened beyond, say, 80 lb-ft without stripping...

For those of you who have replaced your own thrust rod bushings, do you have any tips on removing the bolt that holds the bushing in place, given that it's torqued so tight? I don't have access to a lift, so my leverage won't be great. This being the case, is an air wrench the best option (I have a neighbor with a compressor)? Or is there enough room under there if you jack the car up high enough to muscle the bolt off with a long breaker bar? I've also worried about rounding the head of the bolt. Thanks.

Impact gun would make it easy, but here is a tip when using your box wrenches.

How to Increase The Leverage of Wrench | eHow.com

I used a 21mm wrench on the bolt side and kept hitting it ever so hard with a 5lb lump hammer. eventually it comes loose. just make sure to have another 21mm wrench on the nut side to lock it in place.