Another UCA "clunk" thread [Archive] - Ford Shelby Cobra GT500 Forum

: Another UCA "clunk" thread


inyadreems
05-14-2011, 05:54 PM
Before I explain, 2 things: Not looking to make this a debate on which UCA's or LCA's are better than the next one and in no way shape or form is this negative post about the manufacturer.

After doing research on TS and GT500 I decided to purchase the J&M Non-Adj UCA, LCA's and Adj Panhard Bar (street versions) for my 2010 GT500 to eliminate my wheel hop. My car is mostly spiritedly driven on the street.

My Ford SVT tech did the install. All J&M directions were precisely followed. The pinion angle was within spec and the rear centered to Ford specs. (Note the car is NOT lowered, stock wheels and tires and stock suspension, we reused the original bolts, anti-clunking bushings and lubed all parts very well). The wheel hop is gone and the car takes off nice and straight while spinning but I developed a clunking noise coming from the rear when on and off the gas while in gear and sometimes over bumps.

After talking to Brian at Hotparts, I took my car back to the dealer and the tech went over every bolt re-torqueing them to specs, but the noise is still there. Nothing seems loose; there are no scorch marks on any of the suspension parts that would indicate movement. With the car on the lift and the tech underneath you can hear the noise inside the car when engaging the clutch/gears, but you don't hear it underneath the car. The noise gets louder when the back seat is removed but the UCA mount bolt is torqued and tight. I drove the car with the backseat out and the tech in the passenger seat holding the bolt underneath the seat and there is no movement or play from the bolt. We also lightly used a pry bar on the suspension parts and no noise or movement.
Anyone one have a clue what it could be?

lawdude
05-15-2011, 02:10 AM
Check your driveshaft. Even in spec it can hit the tunnel. I ended up ditching my non-adjustable J&M, replacing it with an adjustable UCA, and setting pinion angle to -3 degrees. My car is not lowered either.

Couple of links:

http://www.fordgt500.com/forums/showthread.php?t=10096

http://www.fordgt500.com/forums/showthread.php?t=6873

Wait a minute, I just realized that I already answered a bunch of questions you had in the first link. I assume the first thing you did was check to see if your d/s is hitting the tunnel. BTW, what's your pinion angle?

inyadreems
05-15-2011, 06:23 AM
I believe the pinion angle was set to -2. Did you have a clunking noise when accelerating or decelerating while in gear with the non-adj. J&M UCA? Didn't notice any marks on the DS or the tunnel.

lawdude
05-15-2011, 06:56 AM
I believe the pinion angle was set to -2. Did you have a clunking noise when accelerating or decelerating while in gear with the non-adj. J&M UCA? Didn't notice any marks on the DS or the tunnel.

Accelerating. If not the DS, I'm stymied.

inyadreems
05-15-2011, 07:31 AM
Me too. We can't figure where it is coming from. We went over everything and re-torqued, also tried moving parts with the pry bar and no movement, slop or play.

lawdude
05-15-2011, 07:40 AM
Me too. We can't figure where it is coming from. We went over everything and re-torqued, also tried moving parts with the pry bar and no movement, slop or play.

If you have the oem two piece steel DS, try putting some chalk on the top of the tunnel and see if it transfers.

inyadreems
05-15-2011, 08:01 AM
If you have the oem two piece steel DS, try putting some chalk on the top of the tunnel and see if it transfers.

Ok thanx

Joe G
05-22-2011, 02:43 PM
Did you get this fixed yet?

Nele22
05-22-2011, 02:55 PM
I also have the same drive shaft "slap" noise under hard acceleration.

inyadreems
05-22-2011, 03:16 PM
Did you get this fixed yet?

Nope, been raining all week and going to rain this week too. Might try and play around with it today, don't know what to do besides re torquing the bolts again with a different torque wrench.