Hey all - just finished with a little overhaul of the car with:

M-18000-C shocks
M-5300-P springs
M-5570-A stops
M-5490-A sways
M-18183-C upper strut mount
Ford Racing adj. panhard
M-5650-A LCA relo brackets
M-5649-S LCA's

And topped it off with the BBS 302S wheels squared up with 275s.

Love the setup, BUT I noticed right away a very loud clunk from the rear end, most noticeably the passenger side. It mostly happens at slow speeds, on uneven surfaces, or while turning. My neighborhood has a section of cobblestone and every time I drive over it it sounds like the car is falling apart. However, at speed, it feels and tracks fine.

Is this simply what I get by going with those LCA's? The clunk is very loud and consistent (does not come and go; it's always there in the aforementioned circumstances).

I want to take the car to a PCA event in a couple of weeks, but I don't trust it as it sits right now. Had a local race shop (very reputable) inspect my install and he said all was good and the clunk was due to the type of LCA bushings, but it's really loud and disconcerting.

If anyone can point me in the right direction, I'd be extremely appreciative!

Thanks in advance!

 

Did you make sure to tighten down the struts in the back with weight on them? If it is one side and not the other then I wouldn't think the LCA's are to blame. Then again I just noticed you went with the 302S LCA's which I think use spherical bushings, so that might account for the extra noise.

 

I did my best to. The shop that inspected it said he actually sat in the trunk to check the tightness and they were good. At a glace, both the upper and lower rubber grommets appear to be under load.

 

It is probably your LCA's then, the FRPP tubular ones come with rubber bushings, but I think the replacements units for the 302S are spherical so they increase NVH.

 

I think you are right, Brandon. Appreciate the help. If I end up not wanting to deal with the noise, would a good switch be to go to the M-5649-R1 LCA's?

Thanks

 

Not sure, I know a few guys have run them and like them. I would suggest the Whiteline LCA's. You can get them from Blowfishracing.com for 259.99 I think. They are awesome compared to the stock ones and they are adjustable should you ever need to adjust them. Also their bushings have been described as magical and really don't increase NVH but they are basically poly bushings as far as stiffness.

 

I have pretty much the same setup and lots of clunking with those spherical rod ends. If you want to add just a little more go for an adjustable UCA with a spherical bearing at the top of the diff Now with my LT headers and o/r H pipe it drowns out all the clunking.

 

Thanks guys. Good to know that it's normal with these LCA's. Sometimes I can live with it and other times like on ****ty roads I think that car is breaking apart! I may end up going with the M-5649-R1 LCA's. Would that eliminate the clunking?

Thanks!

 

There's a pretty comprehensive discussion in this thread. It should answer that question and more......

http://bossmustangsonline.com/index.php?topic=2041.0

 

We're new bolts used at all pivot points including the panhard bar? Bolts have to be torqued properly to give the correct clamp load, old bolts may have stretched to yield and when retorqued do not clamp the suspension point properly. Also aftermarket pats may have looser tolerances than factory bushing sleeves or spherical joints. I had this problem with a UPR panhard bar, clunked like crazy until I finally put the stock one back on.
This winter I changed all the rear suspension, front strut and brake caliper mount bolts for preventative maintenance. The bolt at the panhard rod brace snapped when I started to unbolt it. Something to think about when you track your car.
Steve

 

Thanks guys.

Was the LCA's. I pulled them today and replaced with the stock ones just to test and it was silent. I'll probably get the "R1" LCA's and keep these for just the track.

 

PABOSS, I see you installed the M-18000-C shocks, how are they compared to the OEM Boss shocks and others in the marketplace?

 

I only have about 200 miles on the new setup, but it did get in a canyon run and after a few adjustments it felt extremely dialed in. A lot of it was probably tires, but the whole car felt incredible. I'm used to GT3's and this setup was certainly a step in the right direction. Car's been in storage since early April, but as soon as I get it back out this fall, I'll post more thoughts.

 

it's been about a year, how are the M-18000-C shocks today? and in the past year?