Problem with THDP puck sticking


May 21, 2001
Hey Guys, I have been having a problem with the swing arm not fully closing on my downpipe. It sticks about 20 deg from being closed, but if you wiggle it, it will snap shut. I took it loose from the turbo, and the nearest I can figure is that when it swings around, the sharp puck edge is catching a little bit on the housing and not closing. Has anyone ever had to radius the edge of the puck to get a little more clearance? I placed a piece of flat stock on the DP and the puck edge comes VERY close to hitting it as it swings shut. Thanks

On mine, I had to remove the actuator arm, [grind off the weld], and remove the puck.
I found that the slop in the shaft would allow the puck to slide towards the outer side, and then it would drag on the inner edge of the flange.
I also honed the shaft bore with a split rod and a piece of emery cloth.
I ground the inner side of the flange out, then shimmed the puck to locate it directly over the exh hsg hole. I used stainless AN washers for the shims.Once that was done, I tigged the arm back on the shaft....
Sticking Puck

I had the same problem with my G-Bodyparts DP. I had to smooth the outer edges around the entire circumference of the puck. I also smoothed the edges around the inside of the puck hole on the turbo. I tried to polish them to make them as smooth as possible. A dremel should do it and them polish it with an fine emery pad.

The problem appeared to be that during WG closure the swinging motion of the WG cause some lateral motion of the puck W.R.T. the tubo WG hole surface. This laterally sliding movement will sometimes allow the puck and WG hole edges to get snagged with each other bind up and prevents the puck from closing completely. Grinding and polishing a little radius on both puck and WG hole edges seems to keep them from being hung up.