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Mirror Backing Plate fix - 92 firebird power mirrors
Whelp my driver side mirror crapped out while I was rebuilding the door. The black plastic mirror housing piece with the mirror glued/taped onto it, broke at one of the clips that holds the trunnion in. The glass is intact and the motor and worm gears are ok but when you clip in the mirror to the motor, the lack of connection in the one spot allows the mirror to move. I've been trying to come up with the best way to hold the trunnion on the one side... glue, tape, wire, soldering... something. Maybe someone could redraw the whole piece in CAD to 3D print as a lot of people are searching for this housing piece.
I would replace the whole mirror if that was an option... but I can't find any powered driver side mirrors. There's quite a handful of people I've seen with this problem too just haven't seen any threads on tgo. I also just found out there's multiple styles of this housing. Mine is the one with the clip horizontal.
Let me know if y'all have any ideas or links to something i could try. It can't be that hard to repair right?
Re: Mirror Backing Plate fix - 92 firebird power mirrors
Great suggestion. I started looking at plastic repair and I think I’ll be able to re mold the clip that’s busted and chemically bind new plastic to the piece.
another thought for future purposes of the community might be CAD designing and 3D printing the mirror backing plate so it can be reproduced with little cost and effort rather than trying to mend brittle old plastic. Just a thought
Re: Mirror Backing Plate fix - 92 firebird power mirrors
You could make a tiny L bracket, drill a hole for the trunnion and one for a small screw to hold it to the plastic. For that side id separate the glass so i could use a nut for the screw.
Ive had that issue in the past. No amount of glue, plastic weld would hold it tight enough as the other side. Eventually i found a good piece at the JY, but i never thought of the bracket idea before.
Re: Mirror Backing Plate fix - 92 firebird power mirrors
This would most likely work out of any other fix. The only issue would be pulling off the glass from the bracket and making small enough hardware for the job. If the new plastic mold doesn’t turn out then I’ll go for this. Keep y’all’s updated. 8)
Re: Mirror Backing Plate fix - 92 firebird power mirrors
UPDATE GOT IT FIXED! Super easy repair actually. I ended up buying a plastic repair kit called Plastex.
Basically you make a mold of the good clip using a material that will become plyable above room temperature and solid at room temperature. Once you get the high quality impression you want, fill in the mold with some plastex and put the mold on top of the broken clip. The plastic will flow into the missing spot to make a new clip. It took me two tries cause I had an air bubble in the mold the first time. I figured out that if you hold the mirror vertically putting the mold on laterally, you remove the chance for bubbles to be trapped in the mold.
After curing I cleaned up the bits of plastic slag with a razor and put in the Trunion. I had to spend a little time cleaning the space between the clip and the support that keeps the trunion from sliding, so that the trunion would fit. It clipped in solidly and didn’t shatter the new piece. I highly recommend not ever removing the trunion or mirror again after this cause you risk breaking more parts. These mirrors were not built to be taken apart.
It’s still to be seen how durable this fix is but for now it’s looking great. The plastex kit was $30 and a new mirror would be $90+. Definitely worth it. Highly recommend plastex or something similar.