Cobb RSB won't quiet down

:
MSP & MS3
I had a shop install the Cobb RSB a couple weeks ago on my MS3. They put it on the least stiff setting and greased up the bushings good. A day or two later I started to hear some faint squeaking (squeaky bed) and maybe even a faint thunk when going over bumps. At first I thought it was my imagination... or that my spare wasn't secured... but it only seemed to get worse. So I brought it back... they reinstalled it (on the stiffest setting) and greased up the bushings again. The car definitely feels better on the stiffer setting so, in a way, I'm glad I had/have this problem but this racket won't seem to go away. It's not an issue when the radio's on but pretty damn annoying when it's not. Makes me feel like I"m rolling around in a POS. Anyone know what might be wrong here? I called Cobb and they were like "umm.... derr.... bring it back to the shop... click" This shop is legit and I don't want to be a dick about it. Knowing them, they'd probably take it off yet again and try and figure something out. But that'll be fuedal. I'm thinking there must be something else making the noise. Either that or... perhaps the 16" snow tires are somehow playing a role.
 
I had a shop install the Cobb RSB a couple weeks ago on my MS3. They put it on the least stiff setting and greased up the bushings good. A day or two later I started to hear some faint squeaking (squeaky bed) and maybe even a faint thunk when going over bumps. At first I thought it was my imagination... or that my spare wasn't secured... but it only seemed to get worse. So I brought it back... they reinstalled it (on the stiffest setting) and greased up the bushings again. The car definitely feels better on the stiffer setting so, in a way, I'm glad I had/have this problem but this racket won't seem to go away. It's not an issue when the radio's on but pretty damn annoying when it's not. Makes me feel like I"m rolling around in a POS. Anyone know what might be wrong here? I called Cobb and they were like "umm.... derr.... bring it back to the shop... click" This shop is legit and I don't want to be a dick about it. Knowing them, they'd probably take it off yet again and try and figure something out. But that'll be futile. I'm thinking there must be something else making the noise. Either that or... perhaps the 16" snow tires are somehow playing a role.


FIFY. ;)

Have you inspected your endlinks? Is it possible that they overtorqued the collar bolts? ...or undertorqued them?

This is why I try not to let other people work on my cars...
 
LMFAO since you gave me some good info, I'll reserve my wisecrack for another time. but yeah... thanks. I'll see what they say about that.
 
I had a shop install the Cobb RSB a couple weeks ago on my MS3. They put it on the least stiff setting and greased up the bushings good. A day or two later I started to hear some faint squeaking (squeaky bed) and maybe even a faint thunk when going over bumps. At first I thought it was my imagination... or that my spare wasn't secured... but it only seemed to get worse. So I brought it back... they reinstalled it (on the stiffest setting) and greased up the bushings again. The car definitely feels better on the stiffer setting so, in a way, I'm glad I had/have this problem but this racket won't seem to go away. It's not an issue when the radio's on but pretty damn annoying when it's not. Makes me feel like I"m rolling around in a POS. Anyone know what might be wrong here? I called Cobb and they were like "umm.... derr.... bring it back to the shop... click" This shop is legit and I don't want to be a dick about it. Knowing them, they'd probably take it off yet again and try and figure something out. But that'll be fuedal. I'm thinking there must be something else making the noise. Either that or... perhaps the 16" snow tires are somehow playing a role.

this describes my experience to a tee. lol. I haven't contacted the shop that did it yet, but I hear the faintest little noise sometimes. When you said you felt like you were rolling around in a POS, I can say I feel the same way. I just had the FSB done as well and the TRZ mount(what the hell, it was in the shop and up in the air, might as well have it done) The front clunks over large bumps if the wheel is turned, and it makes some clunking noises coming out 1st. To tie it all together, I'm rolling around on the stock tires which are basically shot, and those are soooo loud and uncomfortable. I think I should bring it into the shop and see what they say...haha
 
I feel your pain. I REALLY need to find a shop in CT that knows WTF they're doing. I like the guys (on a personal level) at the place I brought mine to. They've bent over backwards for me on multiple occasions so I really can't complain. It just seems like I've had issues with almost everything I've had done there. My radio is so F'ed up it's not even worth getting into. So yeah... short of bringing it to a dealership and getting hosed, I definitely gotta get this racket under control. It's the only reason I even got a new RSB. Talk about defeating the purpose.
 
Sorry to hear that man. Mne is not nearly as bad, you can barely hear it without the radio on. And you really gotta listen...but I need to have my FSB taken care of because it's annoying the s*** outta me.
 
Why not just install your own mods????

The how-to's are out there and if I can do it in an apartment (no garage) with just a box of tools and no knowledge of cars . . . anyone can lol.
 
Why not just install your own mods????

The how-to's are out there and if I can do it in an apartment (no garage) with just a box of tools and no knowledge of cars . . . anyone can lol.

Because i would run the risk of ******* my car up badly. I do my own stuff if it's low key...like the COBB TIP, but I don't have any jackstands...which I probably need
 
i have a similar setup, COBB RSB and 16" winter wheel setup, but there is no noise. did you verify yourself the bushings are greased completely? if you have a grease gun pump some grease in there until it oozes out the sides. and don't use petroleum-based grease as it breaks down the rubber. i used Green Grease.
 
Why not just install your own mods????

The how-to's are out there and if I can do it in an apartment (no garage) with just a box of tools and no knowledge of cars . . . anyone can lol.


It's called Risk vs Reward For what they charged, it wasn't worth the hassle. Time is money. Plus, I leave certain things up to the experts.
 
i have a similar setup, COBB RSB and 16" winter wheel setup, but there is no noise. did you verify yourself the bushings are greased completely? if you have a grease gun pump some grease in there until it oozes out the sides. and don't use petroleum-based grease as it breaks down the rubber. i used Green Grease.


Yeah, when I brought it back the second time I speculated it might be the bushings so I had them regrease them... There must be something else going on.
 
Yeah, when I brought it back the second time I speculated it might be the bushings so I had them regrease them... There must be something else going on.

Get under there and have someone bounce the back end up and down see where the squeaking is coming from.
Then either lubricate said area, or replace broken part if that is what it turns out to be.
 
Good Garage, (Actually an old Nike Missle Station)

this describes my experience to a tee. lol. I haven't contacted the shop that did it yet, but I hear the faintest little noise sometimes. When you said you felt like you were rolling around in a POS, I can say I feel the same way. I just had the FSB done as well and the TRZ mount(what the hell, it was in the shop and up in the air, might as well have it done) The front clunks over large bumps if the wheel is turned, and it makes some clunking noises coming out 1st. To tie it all together, I'm rolling around on the stock tires which are basically shot, and those are soooo loud and uncomfortable. I think I should bring it into the shop and see what they say...haha

Hey Bigdaddy, I take my MS3 & Roush Mustang to Competion Autowerks in San Ramon, CA. Its at the end of Bollinger Canyon up a steep hill across from the Regional Park. Ask for the owner, Tom Wickersham, 925-838-1911. He works on spec Miatas, Panoz and all kinds of track and street cars. His knowledge and expertise is second to none. Tell him Bob sent ya!
 
Just an update (as well as an admission that I'm a freakin idiot)

Apparently much (not all) of the sound I was hearing wasn't RSB related at all. Yup... turns out my rubber floor mat thing in the trunk likes to 'shhh-shhh' around when I go over bumps. Oddly, it didn't do that before so I'm guessing the added stiffness of the RSB played a role there. I noticed that all-too familiar sound when unloading some crap from my trunk earlier and the lightbulb starting flickering. I figured there was no way... but after finding the heaviest thing I could, I then realized it was. derrrr...

On top of that, the damn ties (that lift that panel up when you open the trunk) apparently cause quite a racket as well. That's more of a... well, it's hard to describe... but it's annoying as well.

That said... unfortunately, the RSB is still making noise. So it wasn't completely coincidental. I had a shop look at it and, after re-greasing the bushings yet again (3rd time in a month) it's pretty obvious the bushings are just F'ed. So... I gotta call Cobb tomorrow and request a new set. Unless... someone has a better option. I remember buying aftermarket bushings to replace the epic fails Mazda put on the MSP... so, even though these are Cobb... perhaps ther are better ones out there. Anywayz... just figured I'd share in case anyone else has run into a similar problem.
 
I recently installed the Cobb RSB too.

Couple comments. First the bushings need a PTFE grease, not just any grade grease. I used Tri Flow High Perf Syn grease (Grainger 4TA91) which is PTFE based. The bearings are a polyurethane product and some regular greases will degrade plastics. Use a grease gun and load the bearings up. My Cobb had a very small tube of PTFE with the bar, not enough to do the job at all. I learned this from Mustang builders on a previous car, they used PTFE grease on all poly bushings.

Oh, no noise from the RSB at all.

Second, my bar with stock links was very close to the LCA, maybe 1/8" or so. I think this is OK, but if there is any hard corners the stock rubber bearing will flex and I can see that it might touch. I made sure I had all the movement in the direction that kept that space between the bar and bottom of the LCA as large as possible.

I have had the MS3 on the track with the new bar, and it worked very well, an improvement for sure.
 
good advice. I thought all grease was the same. the shop said they greased them up pretty good... I assumed they knew what they were doing. perhaps they did... but I'll definitely run this info by them.
 
It's called Risk vs Reward For what they charged, it wasn't worth the hassle. Time is money. Plus, I leave certain things up to the experts.

I imagine you have seen a sway bar. It's a few bolts and a few bushings and a lot of grease. If it is clunking as bad as everyones says, it's the product and not the installer or the car. Seriously, an 8 year old could put new sway bars on a car. It is a few bolts off then the same bolts back on with grease on the bushings.

Like ole dude said, PTFE is an amazing material. It is used in many severe service industrial applications also, such as cryogenic valves.
 
Last edited:

New Threads and Articles

Back