Please help me troubleshoot my suspension problem

[99 AtlanticBlue]

Here is what I ordered.. H&R sports springs 1.6"F 1.5"R, tociko illuminas (fox body shocks and struts), MM c/c and LCA's.

I installed everything, including the shorter pinion snubber. When I am driving, I hear this loud thump from the rear or at least it sounds like the rear. What can this be? PLEASE HELP!!

Thank you.

 

[Red2000GT]

We need a little more info. When does it thump? When you go over bumps? All the time? Turning corners?

 

[99 AtlanticBlue]

When I go over bumps it happens. But it does not do it all the time I go over bumps.

 

[Red2000GT]

I'd check that you have all the right bushings in the right place on the rear shocks,they might be bangin around. Did you cut the back springs? If so then they will shift sometimes when the suspension is unloaded and they can make a little noise. Did you retorque everything after you drove the car for a few days?

 

[99 AtlanticBlue]

I'd check that you have all the right bushings in the right place on the rear shocks,they might be bangin around. Did you cut the back springs? If so then they will shift sometimes when the suspension is unloaded and they can make a little noise. Did you retorque everything after you drove the car for a few days?

I didnt cut the springs. It feels like I am bottoming out. Everything was installed yesterday and it was "thumping" "banging" however you call it as soon as i hit a bump on the way home. But it doesnt do it on all bumps, maybe just the bigger bumps. I didnt retorque everything just yet.

 

[Red2000GT]

How much did you lower the back?(actual measurments). The fox body springs are shorter to begin with and if they are designed to lower an additional 1.5" then you might be running out of travel. I run FRPP "c" springs that have about 1.25 extra coils cut and I only bottom out if I hit a bump really hard or if I have someone in the back and go over a big bump.
Is it just one THUMP or is it a couple right away when it happens?

 

[99 AtlanticBlue]

How much did you lower the back?(actual measurments). The fox body springs are shorter to begin with and if they are designed to lower an additional 1.5" then you might be running out of travel. I run FRPP "c" springs that have about 1.25 extra coils cut and I only bottom out if I hit a bump really hard or if I have someone in the back and go over a big bump.
Is it just one THUMP or is it a couple right away when it happens?

I didnt take actual measurements. I havent had time, I am so busy with school. It is just one loud thump.

Do you think I should be using the sn95 shocks?

 

[Red2000GT]

I don't think it's the shocks themselves. I'd say just put the car up on jacks tonight and double check everything. Every bolt,nut and washer having to do with the shocks,control arms,etc.
Look at the pinion snubber,see if it looks like it's been hitting the rear end. It should have some dirt scuffs on it if it has been.

 

[99 AtlanticBlue]

I don't think it's the shocks themselves. I'd say just put the car up on jacks tonight and double check everything. Every bolt,nut and washer having to do with the shocks,control arms,etc.
Look at the pinion snubber,see if it looks like it's been hitting the rear end. It should have some dirt scuffs on it if it has been.

thanks for your help!

 

[CobraR19]

How fast/slow are you going over bumps when it makes the thump noise? Highway speed, parking lot? If it's highway speed, then maybe it's just road noise being transmitted through the bushings in your LCAs. I'm assuming you got MM, I don't think you said so specifically but it was implied. Re-check your bolts, if the problem didn't go away just drive it and take notice if the thumping gets worse, or doesn't change.

It could also be the FOX struts and shocks, I don't know the dimensional differences between those and 99+ but I'm sure they're different. Maybe your shocks/struts are bottoming out?

It's tough to discribe a sound on a message forum so I'm just trying to provide options, I could be totally wrong based on what I imagine your thumping sound to be. Good luck!

 

[nickthegenius]

I have H&R Supersports and Mach I shocks/struts(Tokico Premiums). I have a sound that may be the same as what your are getting. I only get the noise from what I would describe as a "sharp" bump where the pavement makes a sudden height change, potholes, etc. Softer bumps (normal pavement variation) do not cause any noise. I have checked all the parts out. I'm marking it up as more road noise being transmitted through the car.

 

[99 AtlanticBlue]

I have H&R Supersports and Mach I shocks/struts(Tokico Premiums). I have a sound that may be the same as what your are getting. I only get the noise from what I would describe as a "sharp" bump where the pavement makes a sudden height change, potholes, etc. Softer bumps (normal pavement variation) do not cause any noise. I have checked all the parts out. I'm marking it up as more road noise being transmitted through the car.

update:

last night I was driving around. I noticed that the sound may actually be coming from the front. let's say i drive off a 1-2 inch ledge. as soon as my front tires drive off that ledge, that's when the noise happens. right when the suspension drops down that
ledge. i noticed it this way because i was driving down a street that they were repaving. as soon as i drove down that "ledge" where the tar has been removed that's when it happens. also, it happens when i drive down a road where that is a dip in the road too.

trust me, it's not road noise. it's like someone bangs on my car with a hammer! HELP!!!!

 

[bmgs01gt]

Hey i have the exact same setup you have and was having the same noises. i fixed it by using the supplied spacers that came with the c/c plates. i just put the 10mm spacer on top of the strut, then tightened it back down. apparently there was not enough threads coming up through the plates, and it wasnt completely tight. this worked for me, hopefully it works for you.

 

[99 AtlanticBlue]

Hey i have the exact same setup you have and was having the same noises. i fixed it by using the supplied spacers that came with the c/c plates. i just put the 10mm spacer on top of the strut, then tightened it back down. apparently there was not enough threads coming up through the plates, and it wasnt completely tight. this worked for me, hopefully it works for you.

you have PM

 

[01LaserRedCobra]

These are a pain and I am not sure where the noise is coming from. I have the MM plates and let me guess it sounds like this...

Message#12
http://forums.stangnet.com/showthread.php?t=425042

(change the .txt extension and change it to .wmv) This will allow you to hear the file. Stangnet won't let you attach .wmv files

I have tried everything and I cannot figure this out. I had stock caster/cambers on with this noise... So I got some aftermarket ones (MM) thinking it would make the sound go away... Nope still there. My spacers are on correctly... the strut top is as close to the hood as possible with out hitting. The top strut nut is torqued good... so good in fact I #ucked up the top of my strut threads from the lock pliars. There is no movement at all from the bearings, and the spacers are solid tight from below and above. I also decided last night to see if all the bolts where tight... so I torqued the K-member, sway bar brackets, links, strut to spindle and lower control arms. Still nothing... still makes that same noise.

I did notice that if you adjust the strut to the softest setting the noise is less noticeable, but I would really like the tires to grip the road good... not float.

Thanks for any help you can give!!!