Roof Rack Threaded Holes/Zerts Broke and are MIA

[UllrAdven]

I found a lot of information on rack removal, custom application, and bolt issues, but did not have any luck with this...

I am in the process of building a custom roof rack for my 04 LC100 and I get down to removing the final 2 bolts on the rear passenger side of the factory rack, and the bolts just begin spinning without protruding. I then manage to pry and turn simultaneously to remove the final 2 bolts without cutting, but now the tread-zerts that attach to the vehicle are gone. Not just stripped, but gone! Meaning no drilling out and retapping with the next size up...

Before I begin ripping things apart to either add temporary nuts, or weld a piece in there some how. Has anyone experienced this before, and what did you have to do to repair and seal things up properly?

The pics are not the best, but this one is of the bad set of holes with no threads

And of a good set of holes

 

[highonpottery]

How about try a nut-sert? Could be a simple fix with these, they don't require much work to use. Maybe use a dab of silicone before installing them. I think even harbor freight carries them.

 

[TXLX100]

^Yep. Try an insert. You'll just need to track down the right size. Google threaded inserts for metal or try one of the auto part stores.

 

[revoked]

If its anything like my FJC, they are loose in your headliner. If you drop that corner you can get them out and reinstalled.

 

[UllrAdven]

I decided to go the route of Rivet Nuts, and riveting threads in there as suggested. The main problem was finding anything larger then 1/4-20.... It just could not be done from purchasing off the shelf, and that is what I put in there right now. Purchasing the correct size on McMaster is roughly $15 for the mandrel, and then 5-$8 for the rivet nuts, but that would also take time that I don't have.

They went in easy once I drilled the holes out an extra .080" or so, and I applied a rubber o-ring and washer to make sure any moisture doesn't leak into the car- Only a car wash will tell-

Revoked- As I was driving in search of these rivet nuts I did hear the damn things rolling around in the back... I might look at doing what you suggest as a better permanent solution

 

[e9999]

The Nutserts -if that's what you mean, the threaded rivets affairs- that I'm familiar with are not intended for heavy loads as far as I can tell. They only hold with a formed flange that has to be soft enough to do in-situ. I would not use them to secure a roof rack. I'd rather not have the thing fly off and kill a little old lady... Not that these roof racks are very strong to start with, either.

 

[UllrAdven]

Hmmm....

What I used was a 'Steel Locking Rivet Nut' Similar to the link below. When I google searched 'threaded insert' this is what came up with.

http://www.mcmaster.com/#standard-threaded-inserts/=vfr6nb

I hear what your saying about that formed flange, and it not being meant for heavy loads, but I am at a loss on what else I could have done without ripping the interior apart. I did choose steel over aluminum for this reason as well.

One things is that if you look at the thread location on these they start past the point of deformation (only logical too) so when more load is applied, the more the insert should attempt to deform. Which make the holding load better to a point. I more fear the steel wall of the vehicle flaring out around the flange, which is why I like the original better.

From what I can tell, (and guess) it seems like the original design was for a PEM nut or 'captive nut'. Does any one know that for sure?
That would have required work from the interior, and pressing or welding...

 

[e9999]

I don't know how exactly they were built originally, and hard to tell from your pics, but, yes, I imagine some sort of captive nut.

The back formed-in place flange of a rivnut is probably not very wide, which if combined with your typical thin sheet metal might lead to it pulling through under overly heavy load. What too heavy a load is for yours I don't know of course, but I would not use one myself for a potentially dangerous application if I'm not sure it's OK, and my instincts -bad as they may be- tell me it's not a very secure way to secure a roof rack with a heavy load on it. I'll readily admit I am no rivnut expert, however. And if the material there is thicker than just the usual sheet metal it might be better or even OK.

Having said all that, I must also add that AFAIR the roof racks on many (all?) 80s have been installed at the port with nutserts it seems, and it's not like they are flying off left and right. Plus it's only one corner in your case.

Of course, it all depends on how much you plan on putting up there.

And yes, not obvious how to do this an other way without major intervention. Perhaps if you can lower the headliner just a bit you could slide in a backing plate with a nut welded on it using a long wire as a handle?