Frustrated and pissed, Help Please....

**Blue_01_Z28** · 06-19-2009, 08:52 PM

Ok so I changed the rear in my car with the dana s-60, BMR lower control arms, BMR adj. torque arm, BMR torque arm relocation bracket, 01 Z28 M6 car. Before my exhaust used to hit sometimes under the car x-pipe with bullets. Now my car seems to ride rought but thats not my real problem. I feel like the tranny is hitting under the car or the torque arm ..... something. If i let off the throttle and let it slow down in gear it will hit. If i roll the car and pull the e brake it hits, also on quick bumps when the rear reaches the bump it hits too. It won't hit as hard if a am accelerating through the bumps.
Has anyone else had this problem after installing the BMR parts? I am goint to check again tomorrow but im frustrated with it.

**mark21742** · 06-19-2009, 09:47 PM

I hate to tell someone to search....but, I think I remember seeing a thread in the suspension section awhile back....try resetting you options so you can read back afew months

**0rion** · 06-20-2009, 12:10 AM

have you checked the tranny mount to make sure it's not broke?

**DaddySS** · 06-20-2009, 12:49 AM

It sounds like your geometry is way off, making it ride rough, banging noises etc. If the torque arm is loaded, it will force the tabs on the tranny mount to rub and bang. How did you set it all up? What was the drive angle?

**35th-ANV-SS** · 06-20-2009, 04:53 AM

I have read about Spohn t/a doing that, not sure about BMR. I have the BMR Chrome Moly Full Length Adjustable Torque Arm and mine is OK.

**Blue_01_Z28** · 06-20-2009, 01:51 PM

Originally Posted by DaddySS

It sounds like your geometry is way off, making it ride rough, banging noises etc. If the torque arm is loaded, it will force the tabs on the tranny mount to rub and bang. How did you set it all up? What was the drive angle?

I set the torque arm in the rear at -2 like in the BMR video but its for an auto and i never could find out if it was the same. The drive shaft is at 0 deg. What are they supposed to be at.

**Blue_01_Z28** · 06-20-2009, 01:51 PM

Originally Posted by 35th-ANV-SS

I have read about Spohn t/a doing that, not sure about BMR. I have the BMR Chrome Moly Full Length Adjustable Torque Arm and mine is OK.

What did you set your angles to?

**cammed goat** · 06-20-2009, 02:29 PM

Sounds like trial and error to me. May have to drive the car and listen to the noises. Try to find out where they are coming from, and get back underneath the car to make more adjustments until all the noise is completely gone.

**DaddySS** · 06-20-2009, 04:32 PM

First, was the car level and the suspension fully loaded when you tightened everything down? If not, loosen the control arms, panhard, etc. and retorque with the suspension loaded. Next - -2 to -3 is the starting point for the drive angle. Check all around underneath, especially around where I mentioned for signs of rubbing or contact, then take 1/2 degree out at a time until the noise is gone. I have the slp torque arm and BMR trailing arms on the stock rear and mine wanted to be two full turns of the adjuster more positive than the starting point and the noise was completely gone.

**TransAm11973** · 06-20-2009, 05:45 PM

when you set everything was the suspension loaded?

**Blue_01_Z28** · 06-20-2009, 06:26 PM

Originally Posted by DaddySS

First, was the car level and the suspension fully loaded when you tightened everything down? If not, loosen the control arms, panhard, etc. and retorque with the suspension loaded. Next - -2 to -3 is the starting point for the drive angle. Check all around underneath, especially around where I mentioned for signs of rubbing or contact, then take 1/2 degree out at a time until the noise is gone. I have the slp torque arm and BMR trailing arms on the stock rear and mine wanted to be two full turns of the adjuster more positive than the starting point and the noise was completely gone.

I missed that the rear wasnt loaded when i tightened the LCA but i'll to that it could be part of my problem. The drive angle you are talking about is that the result from adding the angle from the rear and the drive shaft angle. As of now my rear is at -4 and the drive shaft is at 2 which makes in all for -2 that BMR states it should be for stock height. Right now my car is up the front suspension is loaded and in the rear end I have the jack under the rear end in the center. i have the car level but im not sure if this would be the same as the car being on the floor.

So when you say take out 1/2 degree at a time do you mean from the sum of the two angles or just from the drive shaft or rear? Also do I go say it is at -2 towards -1.5? Thanks for the help i appreciate it. I'll go and drop the car and retorque the LCA and Panhard.

**Blue_01_Z28** · 06-20-2009, 06:42 PM

do you guys think I can break something like the tail of the tranny from that noise hitting. i played with the drive shaft and it has play when I spin it forward and change direction quickly, it will make that noise not as loud but it sounds like it could be the same. Does anyone know about how much play if any when the car is in neutral?

**Blue_01_Z28** · 06-21-2009, 12:25 AM

ok guys/gals I put the car on drive on ramps and broke everything loose, and I loaded and unloaded the suspension by pushing up on the car a few times. I loosened the torque arm as well, then I set the angle to -3 on the torque arm and +1 on the drive shaft. The banging under the tranny is gone but now it seems like there is not enough preload on the torque arm. I just barely set it to where it started to load up. It rides smoother and the hitting noise is pretty well gone but i think i still need to fine tune it.
I wanted to thank you guys that posted up ideas from your knowledge, I learn something new each day from you guys.
Thanks a bunch.

**DaddySS** · 06-21-2009, 04:19 AM

Don't worry about preload on the torque arm. The main idea is to have a slight negative bias on the pinion so when you release the clutch, the drive shaft and pinion are nicely aligned and your lower control arms can control axle torque.

Glad we are making progress!

**Blue_01_Z28** · 06-23-2009, 05:04 PM

Originally Posted by DaddySS

Don't worry about preload on the torque arm. The main idea is to have a slight negative bias on the pinion so when you release the clutch, the drive shaft and pinion are nicely aligned and your lower control arms can control axle torque.

Glad we are making progress!

This might be dumb but can you explain what you mean by Control axel torque? I want to know how that works

**DaddySS** · 06-24-2009, 03:46 PM

Originally Posted by Blue_01_Z28

This might be dumb but can you explain what you mean by Control axel torque? I want to know how that works

As the rear wheels rotate to propel the car, the axle will try to rotate up - axle torque (rotating force). The torque arm the controls that rotating force or torque. The negative preset on the rear is intended to expect that the axle will move some and when it does it will be aligned with the drive shaft. If you don't have a negative preset or the torque arm does not control the torque, you wind up with a positive angle which is not good.

Hope that helps or did I misunderstand your question?