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Mace 25mm spacer install issue

1286 Views 11 Replies 7 Participants Last post by  SC2150
I had to do the plugs on my wife's LY7 CTS, so I decided to go ahead and try the 25mm Mace spacers that I had read about. The install went fine except for one of the replacement bolts in the kit being too short (taken care of by Mace right away - great company to deal with). The problem is that the back of the plenum is so close to this bracket that sticks off of the firewall that it taps against it when the engine is running. Drives my wife crazy. Has anyone else had this problem with the thick spacers?
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Here are the best pictures I can get. Looks like the bracket is part of the windshield wiper support structure. The part of the hitting it is the "motor" mounted to the back of the plenum.

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So, I just pulled the plenum. The plastic box for the variable runner motor was definitely rubbing on that bracket. The bracket looks like part of the firewall and cowl stampings (it is multiple layers of sheet metal). Probably just touching due to tolerances in the stampings and panel joining. I have access to a Bridgeport mill, so I am just going to shave about 1/8" off of the spacers. I don't think the mounts are bad since the engine doesn't have to move much for those parts to make contact.
That's strange, I run a 26 and don't have that issue. I would carefully clearance it with a Dremel.
I thought that would work, but taking off the plenum showed that it was the top of the plastic variable runner box tapping against the underside of that bracket. I would have to reduce the thickness of the whole bracket.
Milling 1/8" worked. If anyone else tries this, be aware that the phenolic material that the spacers are made from is very brittle. I broke one in half taking too much off with the mill. Had to epoxy it back together.
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