Rear end/Drivetrain vibration after adjustable LCA install

[SirMachAlot]

Well the title says it all, I recently installed a TeamZ adjustable lower control arm with spherical bushings on my car and after about taking it up to 60+ I get a vibration in the rear end. At about 90mph it's vibrating really bad. I do have the stock uppers and rubber bushings.
I took my car up to a local speed shop and have them take a look at the length to make sure I was set okay, and also the pinion angle. After I picked the car up I was told that the rear end wasn't even square. One the the control arms were 17 inches and the other was 18. One of the guys told he set the control arms to about 18 1/4 inch in length. So, I thought that might of been the culprit. So i take it on a drive and sure enough the vibration is still there. I told them to check the pinion angle, which i dont think they did. I read a few places that the stock control arm length is about 17 1/2.
Then the shop went on to tell me that the type of bushings I have are going to transmit alot of noise and vibrations since there is almost not play in them, which I already knew, but didn't think it would be that bad. I really don't want to mess anything up so I need some advice/help.
Is it possible that I can adjust the pinion angle with just adjustable lowers and stock uppers?
The car is a 03 mach 5 speed at stock ride height.

[slojunk91]

Originally Posted by SirMachAlot

Well the title says it all, I recently installed a TeamZ adjustable lower control arm with spherical bushings on my car and after about taking it up to 60+ I get a vibration in the rear end. At about 90mph it's vibrating really bad. I do have the stock uppers and rubber bushings.
I took my car up to a local speed shop and have them take a look at the length to make sure I was set okay, and also the pinion angle. After I picked the car up I was told that the rear end wasn't even square. One the the control arms were 17 inches and the other was 18. One of the guys told he set the control arms to about 18 1/4 inch in length. So, I thought that might of been the culprit. So i take it on a drive and sure enough the vibration is still there. I told them to check the pinion angle, which i dont think they did. I read a few places that the stock control arm length is about 17 1/2.
Then the shop went on to tell me that the type of bushings I have are going to transmit alot of noise and vibrations since there is almost not play in them, which I already knew, but didn't think it would be that bad. I really don't want to mess anything up so I need some advice/help.
Is it possible that I can adjust the pinion angle with just adjustable lowers and stock uppers?
The car is a 03 mach 5 speed at stock ride height.

Measure the stock lowers you took off the car and use that as a starting point. Then measure each side at several different points to make sure the rear is square in the car. DO NOT adjust pinion angle with the lower arms,always with the upper(adjust pass side and then just line up the driver side). Pinion angle should between 1.5-2.5 negative, even less with all solid bushings. The idea of pinion angle is O(neutral) at full throttle. Some people may disagree with some or all of this but I've gone 1.38 60' on a 10" tire with this recipe. Hope this helps.

[SirMachAlot]

I've surfed around the internet to find the stock lower control arm length and came up with about 17 1/2 - 17 3/4, can anyone confirm this? I would just measure mine but my problem is my stock bushings were so ate it up, I wasn't even sure where the actual center was lol. They were so bad, every time I hit the gas the rear end would sway out to the side. Could the vibration be happening because of the extra length on the control arms right now and whenever I originally put them in and it wasn't square?

[slojunk91]

Originally Posted by SirMachAlot

I've surfed around the internet to find the stock lower control arm length and came up with about 17 1/2 - 17 3/4, can anyone confirm this? I would just measure mine but my problem is my stock bushings were so ate it up, I wasn't even sure where the actual center was lol. They were so bad, every time I hit the gas the rear end would sway out to the side. Could the vibration be happening because of the extra length on the control arms right now and whenever I originally put them in and it wasn't square?

Very possible.Just did mine with Team Z street beast setup. I'll measure my stock lowers tommorrow and let you know.The bushings in mine were not too far gone.

[SirMachAlot]

Okay, that sounds awesome. Just let me know, cause while I'm under there I'm going to install a pair of battle boxes I got as well, kill two birds with one stone.
Thanks man

[ShakeMe]

Sounds like the pinion angle is too negative. Those adjustable lowers are to center the wheel in the wheel well.

[SirMachAlot]

Could putting in those LCAs throw off the pinion angle? Cause all I did was literally swap out the LCAS and that was it now I'm getting a nasty vibration. When accelerating it isn't too bad but it's there. But on the deceleration it's bad!

[slojunk91]

Originally Posted by SirMachAlot

Could putting in those LCAs throw off the pinion angle? Cause all I did was literally swap out the LCAS and that was it now I'm getting a nasty vibration. When accelerating it isn't too bad but it's there. But on the deceleration it's bad!

Yes it can and will. Squared in the car or too long(neg),too short(pos) pinion angle will cause vibration.

[SirMachAlot]

Originally Posted by slojunk91

Yes it can and will. Squared in the car or too long(neg),too short(pos) pinion angle will cause vibration.

Okay, that was my theory AFTER I installed the arms and the **** was vibrating lol. I'll get under there tomorrow or Friday after you measure up your stockers. I just want to go to Bradenton and try them out, is that too much to ask for :'( lol
Oh and also, I have 4.56s in the car, with out the speedo being corrected, and the vibration occurs at about 80mph(uncorrected). So that will give you an idea on how fast the driveshaft is actually spinning

[slojunk91]

Originally Posted by SirMachAlot

Okay, that was my theory AFTER I installed the arms and the **** was vibrating lol. I'll get under there tomorrow or Friday after you measure up your stockers. I just want to go to Bradenton and try them out, is that too much to ask for :'( lol
Oh and also, I have 4.56s in the car, with out the speedo being corrected, and the vibration occurs at about 80mph(uncorrected). So that will give you an idea on how fast the driveshaft is actually spinning

My stock lower arms are 17 5/8"(checked both). Let me know how you make out @ Bradenton. Man I miss that place, I used to live in Brandon a little over 10 years ago. Lakeland and Sunshine were cool too.

[PeteEpple]

here is what happens when the driveline angles are incorrect...

https://www.facebook.com/photo.php?v...716400&fref=nf

[TKat13]

Just to add to this, I had a 4+ pinion angle, my vibration was exactly as you described. I put in adjustable uppers and set the angle to -1.5 and the vibration is gone.

[slojunk91]

Originally Posted by PeteEpple

here is what happens when the driveline angles are incorrect...

https://www.facebook.com/photo.php?v...716400&fref=nf

they're you go...perfect example of binding (vibration).

[TKat13]

Originally Posted by PeteEpple

here is what happens when the driveline angles are incorrect...

https://www.facebook.com/photo.php?v...716400&fref=nf

that sir, is a great link! Thanks

[slojunk91]

^^^^^x2

[PeteEpple]

every now and then I do something right... haha

[SirMachAlot]

Thank Slojunk! I'll get under there and try to shorten them out, now when I do that, do I need to have the rear end under load, or have it "hanging", noob question lol sorry.

Pete, thanks for clearing that up, It makes so much more since now.

[slojunk91]

Originally Posted by SirMachAlot

Thank Slojunk! I'll get under there and try to shorten them out, now when I do that, do I need to have the rear end under load, or have it "hanging", noob question lol sorry.

Pete, thanks for clearing that up, It makes so much more since now.

Anytime brother...I set mine with the rear unloaded on a lift then double checked loaded on ramps. Worked out just fine.

[SirMachAlot]

Okay! Awesome, I'm going to tackle this project right now, I'll let you guys know how it goes, I appreciate everybody that chimed in for me, thanks once again

[SirMachAlot]

Well, I shortened both arms to 17 5/8 and I'm still getting the vibration at high speeds. I may be a little less then what it was but that may just be me wanting it to stop lol,