Fman67

...OK, i swithched out my aftermarket lower control arms which were mounted in the next to last hole on the BMR relocation brackets...for my oem ones which are supposed to be mounted in the last(bottom) hole of brackets according to instruction..i now have a vibration on hard acceleration...im assuming i meseed up my pinion angle...how do i fix...do i now need an upper adjustable arm? or can i do something else...i switched back to OEM cause i wanted a softer ride...my roads suck here...

RadBOSS

pinion angle. First step is to measure the angle between the drive shaft and the pinion flange face ... car on the wheels at static ride height. 88 degrees would be a good number. You will need an adjustable UCA to adjust if you are not using the adjustable LCAs.

Are you sure the LCA bolts at chassis and axle are torqued to factory spec? If not, do that now. Touchy feely is not good enough. This is a friction connection and when you had it apart you may have noticed the bolts fit rather loosely. So if the bolts are not tight enough, the ends of the LCA will move around making noise.

spyder7724

sounds like a pinion angle problem to me. these cars are really sensitive to changes in the rear suspension including ride height, pinion angle and wheelbase/tracking(housing center).
you will need an adjustable UCA to reset the p/a and an angle finder. try to measure in the same spot each time for consistancy. sometimes it takes a few times to find the happy spot. measure before you make any changes so you have a baseline and make notes so you can refer back to them after changes are made. then you can see if it helped or made the problem worse. this way you will know what direction to make the next adjustment.
most are good at -2.5degrees to +1 degree but each car is different as are measuring techniques so there's no set angle that works on everycar.
also if the car is lowered you may need to space the rear trans mount up a bit to correct the geometry in the driveline.

Fman67

Yes...always torqued..BMR states...when initially installing relocation brackets...using oem arms..."with the suspension loaded,swing the control arm down to LOWEST mounting hole. It is important the OTHER control arm is still attached in the original location before proceeding. This will insure that the wheel remains centered in the wheel well and that the PINION angle remains unaffected." I wonder if i can just loosen it all up...put arms in stock location...load suspension...and retighten...and just do it all over as if i just got the brackets and was installing them for the first time...

Fman67

...Can i just leave what i got alone...install upper adj. arm and adjsut it from there? ...or do i have to loosen it all up again...

TKEUofM

Is it bad to have the relocation brackets if your car isn't lowered?

I have the BMR relocation brackets and tubular BMR lower control arms, but haven't lowered yet. I haven't noticed any problems yet.

RadBOSS

Bracket usually not necessary unless you do lower the car. Would definetely not have the LCA in the lower hole.

RadBOSS

If you change out the UCA for adjustable, you should not have to loosen the LCA's. It is not fun to adjust.

The sequence they gave you for installation of the LCAs was to ensure you do not introduce any torque into the elostomer at ride height. And so that the axle does not get away from you.

I suspect the stock LCA will have interference in the next hole up and is the reason to mount it in the lower position.

GT John

Here is some infor on pinion angle.