suspension issues

since lowering my car i have started hearing and a loud cracking-like noise when i go over a bump and/or rail road tracks. im also getting wheel hop, its an 01 ws6 w/eibach springs,bmr torque arm & lca's, and stock shocks. i have checked everything inside the car and underneath,everything seems to be tight and in place,the only thing i could find was where the top corner of the torque arm has been hitting the bottom of the car in the driveshaft tunnel,im guessing thats the noise im hearing when i go over bumps and such,it looks like the corner of the torque arm is scraping the metal upward,this is the only thing i could find out of the norm,could this be the cause of the wheel hop also? could the stock shocks be the problem letting the torque arm travel too high or do i just need to beat n the floor pan where its hitting so it will clear?

Is your torque arm stock? If so, your pinion angle is now off from lowering the car. The stock torque arm doesn't allow any adjustment either. If you have an aftermarket adjustable one, I would measure the pinion angle and reset it back to around -1.5 to -2 degrees. This will help with the wheel hop.

I also would not hesitate to massage the tunnel for added clearance. Won't hurt anything.

It is a bmr adj. torque arm, the flat part at the top where it bolts up to the rear end is what's hitting, the pinion angle should be set correctly but it won't hurt to check, I'll have to see if I can get the tool from bmr though unless you know of another way to measure it? Also wanted to ask if you know how close the bump stops should be to the axle, mine were only inches away from each other so I took some off because I could tell that when I launched hard the bump stops were sitting on the axle until I let out, not sure if by doing that though if it allowed the rear to go far enough up to hit

I had minor interference in the tunnel with my UMI torque arm. I never heard anything, but the tunnel was dented out and scraped just a bit where the corner on the mount made contact.

Not 100% sure that's where the sound is coming from but that's the only thing I can find at the moment that's hitting, it almost sounds like metal or glass cracking

When you lowered the car, it changed the geometry of the suspension. So unless you physically changed/adjusted the torque arm since it was lowered, the pinion angle is off. You'll need a magnetic angle finder to measure it. They sell them online for a few bucks.

When you lower the car, this will also bring the torque arm closer to the underside of the car. It is a tight fit with aftermarket torque arms to begin with so it's likely you just need to create some more clearance, assuming that's where the noise is coming from.

Be careful on the wheel hop. That will quickly destroy a rear end.

I'm going to chime in and agree with the others that the wheel hop is something you want to address quickly as it is murder on the gear set in the pumpkin. Each time that tire bounced up and down it shocks the teeth on the ring & pinion. Other than making sure you have a good driveshaft angle, if you have a TA relocation crossmember maybe adjusting the angle of connection there and re-adjusting pinion might help a little. Also what setting do you have your LCA at in the relo brackets? Those would have a pretty good impact on a lowered car as well.

ok ill make sure i check the pinion angle first before i do anything else,a friend installed it and said it was right but ill check for myself just to make sure,i dont have a ta relocation crossmember or lca relo brackets,i will try to get the tool asap and check pinion angle and while im under there ill go ahead and massage the tunnel,

When you replaced the front springs, are you sure that you re-installed the isolator on top of the shock mount? If not, your shock may have ripped through the shock mount.

Yes, I bought the springs used and the front struts were already assembled, the noise is definitely coming from the rear though...

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Originally Posted by 35th-ANV-SS

Is your torque arm stock? If so, your pinion angle is now off from lowering the car. The stock torque arm doesn't allow any adjustment either. If you have an aftermarket adjustable one, I would measure the pinion angle and reset it back to around -1.5 to -2 degrees. This will help with the wheel hop.

I also would not hesitate to massage the tunnel for added clearance. Won't hurt anything.

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I massaged the tunnel where the torque arm was hitting and I even filed down the corner of the torque arm slightly last night, I have an angle finder now and ill be checking/resetting the pinion angle, so you're saying to set it -1.5 to -2 degrees?

-2 degrees is the factory setting and typically where you want to have it set on a manual car. Autos are around -1.5. So...just get it close or in between.

Ok my car is a manual, so -2 degrees would still work for a lowered car? I was reading that ride height plays a role in the settings, sorry for all the questions I just don't want to f something up!! Thanks

I found my torque arm was just slightly hitting on my parking brake cable bracket. A few small adjustment with the ol' BFH, and all was well.

No problem. Mine is set to -2 and my car dead hooks with zero wheel hop when I have good tires on it and I'm far from stock power wise. If you have lower control arms, make sure they are bolted to the lowest hole setting also.

If you're unsure what pinion angle is or why it is set-up to the negative angle, let me know. I'd he happy to provide more info.

Forgot to mention, I am also lowered on Strano springs with Koni 4/4 shocks on all four corners.

Just measured +5 on both driveshaft and torque arm, so looks like ill be adjusting

Wow. No wonder you are getting so much wheel hop. Hopefully nothing was damaged. Let us know when you get it adjusted and whether or not you feel an improvement!

I also took a grinder to the corner of the mounting plate on my torque arm.

Well took me all day yesterday to get my torque arm adjusted because of two stubborn bolts not wanting to break loose and doing this on the ground with no lift, but finally got it and took it for a drive this morning and did a couple of hard pulls from a stop and did a burnout and no wheel hop!!! Also drove back and forth over a rail road track and no noise yet so I think the torque arm hitting was making the noise, ill have to get a few more days of driving to know for sure but I'm almost certain that was the cause of the noise, but I'm just glad there's no more wheel hop, thanks to everyone for the help and support its greatly appreciated!!!