Suspension and steering parts wear tests

[timpnw]

New board member here... go easy on me.

How do you know when it's time to replace...

• the coil-over struts (or springs) on the front?
• the coil-over struts (or springs) on the rear?
• the control arms?
• the lower control arm bushings?
• other parts in those suspension kits sold by ecs and fcp?

I recently picked up a '06 66k mi which needs an alignment after adding new tires. What should I look for or replace in advance of the alignment? The obvious answer is everything, but there is nothing really obvious standing out to me while driving it other than a pull to the right at speed. That said I never owned or drove one that was new-ish.

Thanks in advance,

Tim

[oceansize]

For any bushing, ball joint, or mount a visual inspection should suffice. Cracking, flattening, and general condition should be noted. For ball joints excessive play shouldn't be present. Springs/shocks are bit tougher but bottoming out, odd tire wear, too much roll or bounce, etc.

[timpnw]

oceansize Thanks for the reply. Makes sense. While I do some DIY, I'm not going to do an alignment. Should I get an alignment since that's my immediate need and have that shop look for those things? Alternatively, should I put it up on jack stands at home first and have a look around with the wheels off?

[oceansize]

oceansize Thanks for the reply. Makes sense. While I do some DIY, I'm not going to do an alignment. Should I get an alignment since that's my immediate need and have that shop look for those things? Alternatively, should I put it up on jack stands at home first and have a look around with the wheels off?

Definitely visual inspection first followed by any required maintenance first then alignment. Worn out tie rods can make alignment difficult to impossible on the front end. With the mileage you are at it will just depend on how the PO treated and maintained the car.

[K-Dawg]

New board member here... go easy on me.

How do you know when it's time to replace...

• the coil-over struts (or springs) on the front?
• the coil-over struts (or springs) on the rear?
• the control arms?
• the lower control arm bushings?
• other parts in those suspension kits sold by ecs and fcp?

I recently picked up a '06 66k mi which needs an alignment after adding new tires. What should I look for or replace in advance of the alignment? The obvious answer is everything, but there is nothing really obvious standing out to me while driving it other than a pull to the right at speed. That said I never owned or drove one that was new-ish.

Thanks in advance,

Tim

Struts/shocks - when they don't dampen anymore or when they leak
Springs - almost never unless they are rusty/broken
Control arms - when non-replaceable bushings/ball-joints are worn out
Front Control Arm Bushings (FCABs) and Rear Trailing Arm Bushings (RTABs) - more frequently than other suspension parts on these cars. Unless you have record of the ones on your car being replaced recently, you probably need new ones.

Get the car in the air and start pushing and pulling on things to look for any movement.

[Tbonem3]

At 16-17 years old and 66k, I would replace all rubber (fcab, rtab, sway bushes, front mounts, rsms etc), but ball joints like endlnks, control arm ends, tie rods, I'd leave alone. If their rubber dust boots aren't torn, they should last well over 100k.

[timpnw]

Tbonem3 good info. This is why I came here. One clarification. Are you saying to do the strut mounts (rsms and front mounts) w/o doing the struts?

[Tbonem3]

No, I'm saying that at your mileage, I wouldn't replace ball joints. Unless you see that their boot is torn or feel play.

[cobra]

What KDawg said. Get it in the air and jiggle stuff. Play = bad. My control arms are still fine at 100k miles. My FCABs were still tight but actually started to harden up and newer bushings feel softer and more compliant.

Struts/shocks - When they leak or 50k miles depending on road conditions.
Springs - Never as long they are not rusty.
Control Arms - Check ball joints for play. You can jiggle the wheel or squeeze the joints with a large pair of pliers to look for play.
Bushings - RTAB 30k, FCAB 50k

[Tbonem3]

I have seen many instances where a rubber bushing seemed fine, and you couldn't create a feeling of play, yet once replaced, the car, while driving, felt immensely better.

Feeling for play is a better diagnostic for bearings/ball joints.

I would just adopt a policy of replacing all rubber parts at this point in the cars' lives.

[jet_dogg]

Just change everything and be done with it. No telling how the POs drove the car.

The peace of mind is worth it and you can only regret not doing something.

[sapote]

How do you know when it's time to replace...

I would do this instead of just changing everything:
*For front lower control arms bushings and ball joints check: jack up only one wheel off the ground and leave the other on ground, then hold the wheel at 3 and 9 o'clock and rock it back/forth, and repeat at 12 and 6 position. If there is no noticeable plays then they are still good. If there is plays at 3/9 position, look to see if the arm is moving within the rubber bushing (in the lollipop) then only the bushing is needed, but if the plays is at the ball joint (most of the time it's the outer ball joint) then either replace the joint or the whole arm depending on the skillset or parts availability. All check the steering rack tie-rod rubber boots for tear and replace.

[timpnw]

sapote solid advice. Thank you. The car comes out of storage this weekend. I'll be doing what you said. I'm usually with @jett_dogg but I'm deep in this thing as the PO was terrible and I hastily bought it b/c it had the cinnamon interior. Anyway, I budgeted $5k after the purchase and that went fast as I outsourced the work that I was not planning (clutch,vanos and tires). I had an e39 540 in pieces at the time and couldn't have two cars apart and keep everyone in my house happy, Now that I have another car in the stable I can put this up on the stands for a week or so and get down to it.

[jet_dogg]

At the bare minimum I would change without a doubt the following:
-front control arm bushings which are notorious for going bad quickly on most bmws
-rear trailing arm bushings (i have monoball myself)

I'm of the school of thought that says its time or will be time and you can restart the calendar on your watch since you took ownership. If you check them and they're good they won't be good for long and you can't measure incremental deterioration.

Start with the above first and then do these later as a refresh,

Front axle
-tie rods
-front control arms which house the ball joints

Rear axle
-new bushings for the lower wishbone or preferably new adjustable camber arms
-front diff bushing and rear diff cover with new bushings preinstalled since you can't purchase the pair separately
-solid subframe bushings

At 100k I'd do the four ball joints on the rear trailing arm, two on each side upper and lower along with the sway bar bushings and end links.

[sapote]

My 1966 Porsche still has the original lower control arm ball joint with over 300K miles. As long as the rubber boot not torn, no rust and zero plays, I will continue driving.