Sway bushing issues

[hans3]

Recently "restored" my 2800's front and rear sway bar bushings to OEM specs / materials. Did both the bar bushings and the mini-doughnut link bushings. Manual does not cite a tightening spec on the vertical link bushings--conventional procedure is to tighten nut until somewhat snug, then install 2nd jam nut.

Issues: On rear the first nut reaches end of thread travel before bushings are snugged against stop. Note that these are the cheese-colored foam bushings. Result is that there's some vertical play in sway bar link before the bushings create resistance.

On front bushings I tightened the links and the bushings (seemingly new and pliable) cracked in several places. I don't believe I over tightened--just tried to get them snug.


Any similar experiences?

 

[hans3]

Recently "restored" my 2800's front and rear sway bar bushings to OEM specs / materials. Did both the bar bushings and the mini-doughnut link bushings. Manual does not cite a tightening spec on the vertical link bushings--conventional procedure is to tighten nut until somewhat snug, then install 2nd jam nut.

Issues: On rear the first nut reaches end of thread travel before bushings are snugged against stop. Note that these are the cheese-colored foam bushings. Result is that there's some vertical play in sway bar link before the bushings create resistance.

On front bushings I tightened the links and the bushings (seemingly new and pliable) cracked in several places. I don't believe I over tightened--just tried to get them snug.


Any similar experiences?

 

[Honolulu]

thoughts

my car has a rapid rythmic thunking sound on hard left turns that I think is the sway bar where perhaps there is some vertical play in the links or bar mount bushings. Disconcerting. I should get under there....

You don't want play in the system lest it do what (I think) mine is doing.

 

[Honolulu]

thoughts

my car has a rapid rythmic thunking sound on hard left turns that I think is the sway bar where perhaps there is some vertical play in the links or bar mount bushings. Disconcerting. I should get under there....

You don't want play in the system lest it do what (I think) mine is doing.

 

[timt]

Honolulu, also consider a sticky drive shaft "CV" joint binding when at a more acute angle as in a hard turn - this would give a regular clunk as against an irregular one more likely associated with a loose sway bar (anti roll bar). Suggested due to a similar experience/noise some years ago and resolved by refurbishing the joints - it was possible to sense the stickiness by turning in a constant circle at a low speed but quick enough to load the suspension sufficiently to induce the knock.

 

[timt]

Honolulu, also consider a sticky drive shaft "CV" joint binding when at a more acute angle as in a hard turn - this would give a regular clunk as against an irregular one more likely associated with a loose sway bar (anti roll bar). Suggested due to a similar experience/noise some years ago and resolved by refurbishing the joints - it was possible to sense the stickiness by turning in a constant circle at a low speed but quick enough to load the suspension sufficiently to induce the knock.

 

[Stefan]

I bought new bushings from BMW and kept the original bolts and spacer tubes.

My experience was that in the front you needed to use all the threads to get it snugged at all.
In the back, I had to cut off 5mm from the tubes to get it snugged.
(I'm not sure if I cut 5mm from both of the tubes, (the shorter and longer ones))

I can't see what went wrong, but it works now

 

[Stefan]

I bought new bushings from BMW and kept the original bolts and spacer tubes.

My experience was that in the front you needed to use all the threads to get it snugged at all.
In the back, I had to cut off 5mm from the tubes to get it snugged.
(I'm not sure if I cut 5mm from both of the tubes, (the shorter and longer ones))

I can't see what went wrong, but it works now

 

[bengal taiga]

You got rhythm?

my car has a rapid rythmic thunking sound on hard left turns that I think is the sway bar where perhaps there is some vertical play in the links or bar mount bushings. Disconcerting. I should get under there....
You don't want play in the system lest it do what (I think) mine is doing.

The way you describe your vibration makes me wonder first about the road surface. But, if you suspect sway bar bushings as a cause, I would not rule out a few other things such as a the exhaust system lightly banging against the undercarriage or worse. Rubber exhaust hangers do stretch or loosen up with age and constant vibration.

When I say worse, I am referring to the portion of the body onto which the rear shocks are attached. That area can be cracked from simple fatigue and go unnoticed until just the right conditions.

Then again, I think I have heard similar noises that disappeared when I readjusted the trunk board above the spare tire. It also occurs to me that an unsecured object in the trunk (or even the trunk mounted tool carrier) could contribute to occult sounds.

 

[bengal taiga]

You got rhythm?

my car has a rapid rythmic thunking sound on hard left turns that I think is the sway bar where perhaps there is some vertical play in the links or bar mount bushings. Disconcerting. I should get under there....
You don't want play in the system lest it do what (I think) mine is doing.

The way you describe your vibration makes me wonder first about the road surface. But, if you suspect sway bar bushings as a cause, I would not rule out a few other things such as a the exhaust system lightly banging against the undercarriage or worse. Rubber exhaust hangers do stretch or loosen up with age and constant vibration.

When I say worse, I am referring to the portion of the body onto which the rear shocks are attached. That area can be cracked from simple fatigue and go unnoticed until just the right conditions.

Then again, I think I have heard similar noises that disappeared when I readjusted the trunk board above the spare tire. It also occurs to me that an unsecured object in the trunk (or even the trunk mounted tool carrier) could contribute to occult sounds.