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Discussion Starter #1
I recently lowered my car about a month ago now. Everything went smooth. I am on BMR springs and panhard bar to align the rear. Stock shocks/struts for now. I actually just 2 days ago was able to get back under the car and checked to make sure the bolts were within factory torque spec via a torque wrench. When I initially did the work I tightened everything basically as tight as I could get it with normal tools and then just recently torqued them within spec (didn't have a torque wrench at that time).

Now, I am hearing a popping noise when I hit large dips/bumps. I was not hearing this before torquing everything. It seems to only occur on larger bumps or dips, not on normal lesser bumps / dips.

I also noticed the panhard rod had leaked out a good amount of grease from the driver side poly bushing fitting on the panhard rod. Not sure if that was only because it was excess grease from initially pumping some grease in it or if I have a issue.

Also, I can't quite pinpoint where the noise is coming from exactly. It sounds to me it actually is only coming from the passenger side/rear.

Anyway, everything should be as tight as it should be. Just seems odd this is now occurring. Could the noise I am hearing be from hitting the bump stops? I didn't modify those at all, they are in their stock condition. Also, maybe is the noise coming from the panhard rod?

Thanks ahead of time for the help / advisement.
 

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good with the steel.
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Howmany miles on the car.

What was the amount of drop.

Did you replace the strut mounts.
 

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At the Apex pulling 1.28g
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Did you tighten the jam nuts on the PHB after adjusting the length of it to center the rear axle? If you did, get under there and REALLY tighten them...

Recheck all the torque on the nuts and bolts.

Also make sure your rear swaybar is mounted tight if you removed it.
 

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Discussion Starter #4
The car is just about to turn 15k miles. Its been on the springs about 500 miles. Did not replace shock mounts, didn't think I didn't need to. Drop is 1.5 in the rear 1.25 front.

Whiskey I did not recheck the Jam nuts. I got them pretty tight first go round and put lock tight on it. I will double check them though and REALLY tighten them. All the other bolts are within spec, at least to my knowledge they are. I will double check on all the bolt torque specs again. I checked the sway bar bolts, strut bolts, and pan hard bolts. All should be within spec.
 

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Discussion Starter #6
I've heard of people replacing the front shock mounts never the rear. Yes it does sound like its coming from the back right (passenger). I know I am probably shortening the life of the shock / struts by lowering it on stockers but its only been about 500 miles. I'd also imagine if anything were to go out it would be the front ones first due to the engine weight.
 

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Biz Jet Fixer
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There are no mounts on the rear. The fronts are struts and therefore use strut mounts, the rears are shocks and don't have "mounts" so to speak.

Could be your exhaust banging around. Check clearances.

IMO, you should've saved up another $400-600 and replaced the struts/shocks while you were going through the process. It's always best to do it right the first time, even if it means waiting a couple months longer.
 

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Discussion Starter #8
oday 04:07 PM
jdos1 There are no mounts on the rear. The fronts are struts and therefore use strut mounts, the rears are shocks and don't have "mounts" so to speak.
Exactly

Yes I probably should have saved a bit more for some shocks / struts. However I did what can be considered a very mild drop. The ride quality is actually surprisingly good. My only beef is this new noise.
 

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Discussion Starter #10
Regardless you should still get about 60k outta the factory struts. Not like the car is slammed.
My thoughts exactly. I will do some extra checking. Gonna go back and check each item at a time to get an idea. First thing I am going to do is re-tighten the jam nuts. I have a feel I can get more torque on these. Does anybody know what a recommended torque to put on these?
 

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Discussion Starter #11
Update:

I was under the rear or the car again around x-mas time. I was installing a BMR panhard rod brace and LCA relocation brackets. I backed off all of the bolts I messed with during the install of the lowering springs from the previous install. I re-torqued the bolts (strut mounts, sway bar bolts, panhard, panhard brace, and control arms bolts) all to factory spec with a torque wrench.

I am still getting the popping or banging noise from the rear. Same noise as before. I also previously had put a dab of grease on my bump stops when I first noticed the noise. When under the car I had a good chance to look at the frame rails. My bump stops are indeed making contact with the frame rails. I can see some grease has transferred from the bump stops to the frame rails.

This is the only thing I can think of that is cause for the noise. It seems to only occur when there is a good amount of body travel where it would be expected to make contact with the bump stops. Like over large humps in the road where the body will travel up higher and comeback down harder.

I have BMR LCAs on the way so when I do the install I will chop the bump stops down a bit and see if this remedies the issue. Stay tuned.

Any other ideas are welcome as well
 

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Yeah when those stops hit it's a pretty loud bang from under the car, BTDT at the track, many times, even with just 55D springs in the back. Anything lower, I'd expect you'd be hitting them quite easily, even with firmer damping from the struts and shocks.
 

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i have the same noises on my car under acceleration when i hit a crack inthe road or a dip. first time i did it i thought i broke something. kind of sounded like the loud bang when i broke the rear end in my foxbody. My car is not lowered but i have upper and lower control arms. I havent had a chance to look under the car since i am away for another month and cant just go in the garage and jack the car up. Im sure its nothing to worry about just loud and annoying
 

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Discussion Starter #16
Clunk noise might be the sway bar. Are the end links tight?
As I have mentioned the sway bar bolts are tight as can be and are within factory torque specs (85ft/lbs).
 

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'Stang Noob
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Update:


I am still getting the popping or banging noise from the rear. Same noise as before. I also previously had put a dab of grease on my bump stops when I first noticed the noise. When under the car I had a good chance to look at the frame rails. My bump stops are indeed making contact with the frame rails. I can see some grease has transferred from the bump stops to the frame rails.

This is the only thing I can think of that is cause for the noise. It seems to only occur when there is a good amount of body travel where it would be expected to make contact with the bump stops. Like over large humps in the road where the body will travel up higher and comeback down harder.
Go with a stiffer shock/strut set up. Now that you're lowered the spring rates are probably not strong enough to keep your bump stops from hitting over large bumps with the soft stock shocks/struts.
 

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It's not unusual to get that clunking with an aftermarket panhard, although BMR is a high quality piece. I've had a few buddys have that problem with cheaper ones (UPR), and heim joint types. In both cases, the problem was solved by replacing the bar with a polyurethane bushing type bar (Steeda). Aren't you supposed to cut down the rear bump stops when you lower these cars? BTW, not new to Mustangs, just this forum...
 

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Discussion Starter #20
It's not unusual to get that clunking with an aftermarket panhard, although BMR is a high quality piece. I've had a few buddys have that problem with cheaper ones (UPR), and heim joint types. In both cases, the problem was solved by replacing the bar with a polyurethane bushing type bar (Steeda). Aren't you supposed to cut down the rear bump stops when you lower these cars? BTW, not new to Mustangs, just this forum...
The BMR panhard bar I have is a poly bushing setup. I don't know if there is any set in stone procedure that you would need to cut the bump stops. I think it depends on the setup. I thought with mine being a very mild drop I'd be fine but that's obviously not the case. I have BMR LCA's on the way so I will install those here soon and when doing so I will chop the stops down to half length. I guess stay tuned if this fixes it.
 
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