Clunking H&R Front Sway

[rumatt]

WTF causes it?


My H&R 27mm front sway clunks like mad. It never used to, but it has started over the last 4 month or so of use. I know it's the bar because I just put it back on after the winter and it's clunking loudly (everything else is stock). I greased the hell out of the bushings, so it's not that.

I called Turner and the conversation went like this:

ME: "Do you sell just the bushings for the H&R front bar?"
THEM: "Your bushings are bad? That almost never happens."
ME: "I don't know, they didn't look so bad, but what else could it be?"
THEM: "Clunks are often not the bushings, but another problem with the suspension"

I also noticed that the bar itself is fairly worn where it touches the bushings. Some of the paint is missing. :ack:

Suggestions?

Just try the new bushings?
Grease them or not? They also claimed they don't even need grease.
Are there more durable options? (powerflex, etc)?

[bren]

Unhook the bar from the struts and move it up and down to check if it makes noise at the bushings.

[Plaz]

Slightly stripped bolt hole on a bushing mount, maybe? Enough to let a couple of threads make some noise as they slip through? :dunno:

[rumatt]

Unhook the bar from the struts and move it up and down to check if it makes noise at the bushings.

Already checked and it slides smoothly, thus I was not expecting any clunks. I thought sway clunking was when the bushings weren't lubed well so they would hold tight until the pressure built up, then release. But that can't be what it is now because they're lubed like crazy and it moves freely.

Slightly stripped bolt hole on a bushing mount, maybe? Enough to let a couple of threads make some noise as they slip through? :dunno:

Oh, interesting. I hadn't thought of that.

I guess I'll have to get under it and try to reproduce the noise by hand, but the last time I tried this I wasn't able to do so with the amount of force I can generate by hand (and without knocking the car off the jack stands, quickly deading myself).

[bren]

Does it clunk if you bounce the car up and down?

The bushings are poly right? I expect it would be readily apparent if they are shot.

[rumatt]

Does it clunk if you bounce the car up and down?


Nope. It clunks most when I go over the speed bumps in my complex at a slight angle, so the car leans side to side. It clunks when the front wheels go over, then again when the rears go over (because the rear makes the car tip, which makes the sway do work).


The bushings are poly right? I expect it would be readily apparent if they are shot.

Uh, yeah I guess. :dunno: They bushing itself it in reasonable shape, but I was thinking it had word enough to create extra play or something.. I'm becoming convinced it's not the bushings.

[bren]

It's probably the subframe tearing out of the body :p

[rumatt]

It's probably the subframe tearing out of the body :p

No, that's the rear clunk.

[John V]

I know exactly what the problem is.

The aftermarket sway bars almost never have the correct size hole drilled for the endlinks. They are typically too large.

If you don't crank down the endlink bolts enough, the endlink bolt will move up and down in the sway bar end, causing a clunk. Really annoying. Tighten the endlink nuts and see if it goes away.

[clyde]

I know exactly what the problem is.

The aftermarket sway bars almost never have the correct size hole drilled for the endlinks. They are typically too large.

If you don't crank down the endlink bolts enough, the endlink bolt will move up and down in the sway bar end, causing a clunk. Really annoying. Tighten the endlink nuts and see if it goes away.
It's a BMW, Jim, not an RX-8.

:D

[John V]

LOL, this happened all the time on my M3.

And the RX-8's sway clunked because the nuts kept backing off. :ack:

[Plaz]

And the RX-8's sway clunked because the nuts kept backing off. :ack:

You and clyde lifting on a sweeper caused the sway to clunk? :p

[rumatt]

The aftermarket sway bars almost never have the correct size hole drilled for the endlinks. They are typically too large.


Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh.

That sounds exactly like something that would cause this type of noise. It never made any sense that it would be the bushings could make this noise.

I will try that tonight. I'm not sure cranking the hell out of the nuts is the right long-term solution though. I wonder if I make sense to fabricate something around the endlink or something crazy like that.


You and clyde lifting on a sweeper caused the sway to clunk? :p

Booooooooooooooooooooooooo

[clyde]

And the RX-8's sway clunked because the nuts kept backing off. :ack:

Except at the end.

I wonder how those hardware store grade nuts are doing on that car now.

:eeps:

[rumatt]

Except at the end.

I wonder how those hardware store grade nuts are doing on that car now.

:eeps:

:bustingup :ack:

[rumatt]

Well I'll be damned. It was the bushings after all.

First I checked the nuts on the end links, and they were tight as could be.

Then I disconnected one end of the bar and rammed it up and down. The noise was because there was a small amount of play between the bar and the bushings. I wrapped the bar in teflon/plumbers tape at the points where it sits in the bushings (something I've seen mentioned on fanatics), added some grease, and now the clunking is gone.

I don't know if the play is caused by the bushings being worn, or the bar itself. The bar has some kind of black outer coating (paint? rubber?) and it is worn away where the bushings are. Maybe a lack of grease from before caused wear, and now I need to fill the gap with teflon tape. I can't imagine that tape will be very durable though. I'm guessing it will need to be replaced every few months.

[bren]

So buy new bushings. Easy enough.

[rumatt]

So buy new bushings. Easy enough.


I don't know if the play is caused by the bushings being worn, or the bar itself. The bar has some kind of black outer coating (paint? rubber?) and it is worn away where the bushings are. Maybe a lack of grease from before caused wear, and now I need to fill the gap with teflon tape.


And maybe a new bar... :dunno:

But yeah, if the tape doesn't last long I'll try new bushings.

[bren]

How about trying the stock rubber bushings?

The outer coating on the bar is most definitely powder coating, which you could have redone...or you could try some paint like POR15.

[rumatt]

How about trying the stock rubber bushings?


Hmm, good idea. They might be too small, but worth a shot.

If too small, I can try a bushing for another brand bar that's in between.

[rumatt]

Clunk is back already :rolleyes2

Tomorrow I'm going to order a set of UUC bushings. Apparently they're 25.5 mm instead of H&R's 27.

[rumatt]

Hmmm... interesting.

I called H&R. The guy claimed that I probably ruined my bushing by using grease on them when I installed them. He said you absolutely cannot grease them unless it is a Teflon lubricant. Their bushings have a Teflon lining that a) does not need grease, and b) can be ruined by grease. The grease can eat away at the rubber/liner and cause it to become ineffective.

He said that getting new bushings might help. However, because I've caused my bar to become scraped up and rough where the bushings are, the uneven surface (and it is quite uneven) will likely ruin the new bushings in a short time. Recommended long-term solution? New bar.

Bottom line: Don't put grease on H&R Teflon-lined bushings.

A new H&R bar (with bushings) is $185 at TMS. I could just order that. Does anyone have a used sway they're trying to get rid of?

.

[Pinecone]

Hmm, how long were they in?

I have H&R sways and greased the bushings, as we did on Mike Trent and my friend Erich's cars. No problems so far.

[rumatt]

I had them installed for only about 10 months, but I bought them used with about 20K miles on them. I don't know how they were installed on the original owner's car.

Bren pointed out that a M3 stock bushing might fit. They're 26mm, and cost $4.00 each according to realoem.com. I'm going to try to smooth out the bar, use the M3 bushings, and see what happens.

[rumatt]

Wow, wow, wow, wow, wow, wow!

I finally got around to trying the M3 stock bushings. I can't believe how much of a difference it makes in steering response. The slop in the bushings translates directly into a dead spot in body roll before the sway kicked in. I was shocked on the test drive.

What I did: I sanded down the bar to get rid of the unevenly worn rubber coating. The M3 bushing was still a tad too small, but I put some grease on the bar and crammed it on anyway. I also had to add a touch of grease to the outside of the bushing, otherwise the metal sleve would bind on the rubber pulling the bushing apart, rather than squeezing it together.

But it squeezed around the bar nicely when I tightened down. I'm not sure how long the stock bushings will last, but at $3.50 each, I think I can afford to replace them each season.

[bren]

What a great idea! :p

[rumatt]

What a great idea! :p

:worshipb:


:D