w261w261
07-30-2009, 06:45 AM
A couple of months ago I installed a couple of camber-adjusting UCA mounts, as my right side had hit a pothole with the prev owner, and the camber was an extra 1 degree negative. Combined with the 1 degree negative change from the Eibachs, I thought it was too much. I have revalved Bilsteins also.
After the work, which included replacing all the shock rubbers, when I hit a moderate pothole with sharp edges, I would get a real metal-on-metal bang from the right front. This happens maybe once a week or so, when I can't avoid the hole. It only happens on sharp impacts. It is also OK on the left.
As part of the changes, I installed poly washers on the UCA mounting bolts. Thinking that the right mounting bolt was not torqued correctly, I tried to retorque it to 40 ft-lbs. I couldn't get there because the washers started cupping, which I didn't think was good.
I finally went back to the shop that did the work, after finding a suitable pothole around the corner, and confirming that I could make the noise happen. I loaded the mechanic in the car and went for a demo ride. First I hit the hole on the left side...no problem. Then I turned around for the right side. IT WAS JUST LIKE THE LEFT! I hit it four or five times, perfect. The only thing that changed was the addition of some extra weight on the right side. I suppose that my weight on the left has had the same effect.
So my question is, why is this extra preload apparently removing the problem, which didn't exist before the UCA mounts install? Unfortunately, I do most of the driving by myself. I'm thinking of removing the poly washers and substituting metal ones, so maybe I can get to the correct torque values, although I'm not sure what the OEM washer is.
Ideas? Thx.
After the work, which included replacing all the shock rubbers, when I hit a moderate pothole with sharp edges, I would get a real metal-on-metal bang from the right front. This happens maybe once a week or so, when I can't avoid the hole. It only happens on sharp impacts. It is also OK on the left.
As part of the changes, I installed poly washers on the UCA mounting bolts. Thinking that the right mounting bolt was not torqued correctly, I tried to retorque it to 40 ft-lbs. I couldn't get there because the washers started cupping, which I didn't think was good.
I finally went back to the shop that did the work, after finding a suitable pothole around the corner, and confirming that I could make the noise happen. I loaded the mechanic in the car and went for a demo ride. First I hit the hole on the left side...no problem. Then I turned around for the right side. IT WAS JUST LIKE THE LEFT! I hit it four or five times, perfect. The only thing that changed was the addition of some extra weight on the right side. I suppose that my weight on the left has had the same effect.
So my question is, why is this extra preload apparently removing the problem, which didn't exist before the UCA mounts install? Unfortunately, I do most of the driving by myself. I'm thinking of removing the poly washers and substituting metal ones, so maybe I can get to the correct torque values, although I'm not sure what the OEM washer is.
Ideas? Thx.