Screws holding up the Cloroplast cover

[dan00500]

I've got a 2018 Mallard and need to get the cover off the underbelly, but the heads keep sheering off the screws. I've tried by hand, with an impact drill, and normal drill. None of them unscrew. Instead, the top of the screw just twists until it has twisted off.

They are weird looking for screws too. Long heads with a plastic thing on the shaft of the screw before it was screwed in. That plastic thing seems like it's meant to widen the margin of tolerable error when screwing them in at a fast pace.

Should I just expect to sheer off the rest of the screws?

Regardless, I would prefer to improve the screws while I'm doing this work. What's the right screw to use for replacing the cloroplast when I'm ready?

I'm assuming it should be at least a self-tapping, zinc coated screw. Or, is there a better version of rust prevention?

And, for the length ... Maybe 1/2", 3/4" or 1.0 inch long? For thickness, maybe #6, #8, or #10 perhaps?

Thanks.
**Dan

 

[Bones]

I've got a 2018 Mallard and need to get the cover off the underbelly, but the heads keep sheering off the screws. I've tried by hand, with an impact drill, and normal drill. None of them unscrew. Instead, the top of the screw just twists until it has twisted off.

They are weird looking for screws too. Long heads with a plastic thing on the shaft of the screw before it was screwed in. That plastic thing seems like it's meant to widen the margin of tolerable error when screwing them in at a fast pace.

Should I just expect to sheer off the rest of the screws?

Regardless, I would prefer to improve the screws while I'm doing this work. What's the right screw to use for replacing the cloroplast when I'm ready?

I'm assuming it should be at least a self-tapping, zinc coated screw. Or, is there a better version of rust prevention?

And, for the length ... Maybe 1/2", 3/4" or 1.0 inch long? For thickness, maybe #6, #8, or #10 perhaps?

Thanks.
**Dan

If the screws are rusty most of the time you will shear the heads off. When out you will need to back out the rest of the screw or hammer it through with a punch. Just put in Stainless screws on the next go around.

 

[Semi-Hex]

Those weird looking screws may be ramset nails. Part of the head is plastic and the shank is unthreaded. Take a large set of offset diagonals and try prying the as straight down as possible. I had nine or so of them in my front cover.

 

[TXgearhead]

I haven't had the "nail gun screws", but I have the self drilling, self tapping screws. I got replacements at Fastenal. Stainless Steel. Don't remember what size but had a 3/8" head/socket size. You might have to get stainless steel washers as well. "Fender" washers would be best. My Oshkosh apparently has a pretty tough frame (heat treated??). I had to drill pilot holes. A lot tougher than the previous Montana HC.

 

[CarterKraft]

The right tool for the job.

In my opinion (somewhat professional) the screws they use at the factory are the wrong screws for the application. They are far too coarse thread for the thickness of frame steel. They are also poorly coated and rust easily (cheapest vendor most likely).

The correct screws are this flavor, Tek 5 self drilling screws. You will still need fender washers in what ever material you fancy but the screws will drill up to they're rated thickness like a brand new drill bit and thread right in with outstanding torque holding ability.

I get them from my dad who works in the steel erection industry but they are available at the usual sources.
They don't replace a conventional self tapping screw for sheet metal use but for structural steel 1/8" thick and above these are as good as a bolt (in there size range).

 

[TXgearhead]

Good info.
I'm not into sheetmetal and structural steel. Narrowly focused on petrochem turbo machinery, or was.
Now retired.

 

[dan00500]

Those weird looking screws may be ramset nails. Part of the head is plastic and the shank is unthreaded. Take a large set of offset diagonals and try prying the as straight down as possible. I had nine or so of them in my front cover.

The "screws" indeed turned out to be nails. I'll try finding some a large offset diagonal cutter to do the job. This is what Harbor Freight has online for sale:
https://www.harborfreight.com/11-in-long-reach-diagonal-cutters-64086.html

 

[Semi-Hex]

The "screws" indeed turned out to be nails. I'll try finding some a large offset diagonal cutter to do the job. This is what Harbor Freight has online for sale:
https://www.harborfreight.com/11-in-long-reach-diagonal-cutters-64086.html

If you shop Harbor Freight, this would be better. https://www.harborfreight.com/8-in-high-leverage-diagonal-cutting-pliers-with-angled-head-63826.html

Once you grab the nail, put a thin scrap of wood behind the head for better leverage.