GMC 4905 Marker Light Passenger Side

pabusnut · August 10, 2019, 03:17:02 PM

I am looking for a marker light for the Passenger side marker light for my 1973 GMC 4905.
When I went to make sure all my lights work for inspection, I discovered this non working one is cracked and has a big hole in the top which I couldn't see from the ground.

And of course the bolts wont come out even with an impact driver.

If I cant find a replacement, I guess I will be redneck engineering something which will ruin the "classic lines of my bus", but at least it will be roadworthy.

Thanks!

Steve Toomey

richard5933 · August 10, 2019, 03:30:01 PM

Front or rear (red or amber)?

I'm sure you know, but the bolts go into threaded rivet-type inserts. You could try dripping/spraying penetrating oil on it to break it free.

I do have a couple of spares, depending on which corner you're looking for.

chessie4905 · August 10, 2019, 03:38:01 PM

I think it is the same as the lower ones. I got two new ones from Luke last winter. If ha cant get them any more, mention it here and I can give you a source of a beautiful slightly larger ones. The protective shields won't fit on the slightly larger ones however. I used a small carbide burr with a Dremel on one screw that just turned in the nutsert. After carefully removing the washer like lip that held it in place, I replaced the nutsert.

pabusnut · August 10, 2019, 04:24:05 PM

Sorry, I wasn't thinking on the first post--Front -Amber above the passenger door.

I will call Luke Monday and see if he has one or two. The other ones look OK for now, but if the bulbs go out I am pretty sure they are rusted in place too. I probably ought to look for stainless bolts for all four corners when I get these out.

Steve

richard5933 · August 10, 2019, 04:28:33 PM

I was afraid that it would be the right front. That's the one I just worked to find.

With the hole in yours being on the top and out of sight, can you use epoxy resin to make a repair to it?

pabusnut · August 10, 2019, 06:38:56 PM

Maybe I can use epoxy, but I am not sure the "missing" piece is even inside.

I will probably be looking for a source to manufacture some of these, even if I get mine fixed. My other one is very faded, and not in much better shape.

Steve

richard5933 · August 10, 2019, 06:47:43 PM

I guess I wasn't thinking of just gluing the piece back in place, I was thinking more of using some type of plastic to make a 'mold' and then filling the space with tinted resin. There are kits at the parts stores to do this, I think.

I was able to find the lenses I needed for my bus, so they're still out there. Just takes a bit of hunting to find the right ones.

pabusnut · August 12, 2019, 08:55:02 AM

Luke Saves The Day Again!

Luke at US COACH has the new old stock complete assembly in stock at less-than-unobtainium pricing, so it is on its way to me shortly.

Now I just have to get the old one off without totally gouging up the skin of the bus. The bolts won't even come out with an impact driver, but I haven't tried the hammer drill yet. I guess the last resort is drilling out the bolt heads.

Steve

chessie4905 · August 12, 2019, 09:52:11 AM

Use a Dremel or air die grinder with a 1/8" diameter ball end carbide burr. After you get in about 3 /8" , switch to a 1/4" one till the head comes off. Soak the stubs where they go into the rivnuts for a couple of days while occasionally reapplying. Use something better than WD-40. If you can't get them to loosen, cut flush and carefully remove lip of rivnut till it falls through into body. I used a cut off blade on my Dremel and carefully used the edge of blade to remove lip.Install new rivnuts and use ss screws with antiseize to reinstall. You can install new rivnuts without a special tool. Just take a long bolt with same threads and run a nut then washer onto the bolt. Thread bolt into rivnut, fully engaging threads. Run nut and washer down onto surface of rivnut and tighten with a wrench to seat rivnut. You could put some thread locker on underside of rivnut lip to assist it from turning in hole.

pabusnut · August 12, 2019, 11:41:09 AM

John,

Thanks! I wasn't even thinking about the Dremel tool.
From the sounds of it, you have done this more than once.
I do have a rivnut tool, but not sure I have the parts for this size.

Steve

chessie4905 · August 12, 2019, 01:11:11 PM

I just removed my front ones from the parts coach and sold them to Richard.

pabusnut · August 12, 2019, 05:23:09 PM

OK, so I got the RF off, and discovered the LR wasn't working either, so it came off too.

I had to grind out the bolts on the RF, and cut out the rivnut. On the LR, one bolt actually came out, but the front one had to be cut.

So I put in 3 new rivnuts, and now need to go buy 4 SS 1/4-20 flathead bolts. I will probably try to find ones with Allen head if available.

Now to get the windshield washer working again, and I should be good for inspection after the part arrives from Luke.

Steve