I'm working on doing the first round of oil changes since getting my '09 FLHP but the bolts on the derby cover are on so tight that I can't move them and I'm afraid of snapping them or doing other damage. I've attempted to remove the bolts with a short breaker bar and a gentle tap with a impact wrench but nothing is. moving. I can't believe someone would put these on so tight but needing some advice on removing the bolts without doing damage.

 

Try a bit of heat. If you have a soldering iron heat the tip with that, tap and try again
Make sure you use a T27. Sad how some dealership techs hulk these on. I had the same ones on my 07 when I sold it last year . Hand tightened always.

 

What he said, T27 and hand tighten. If you have to, you can drill off the heads and install new screws. The stub of the screws that's left will likely come out easily with vice grips. That's what I ended up doing, went back with stainless allen head.

 

The information above is very good.
In addition, check if the bottom ones are just as tight.
Sometimes one bolt is super tight and that jams the other bolts.
My opinion: some people use battery operated tools when installing bolts with no regard to torque applied.

 

Loctite the **** out of everything it a Harley Wrong answer. Heat when warmed up put the Number 27 in a tap it with a hammer then remove it.

May require a second heat up.

 

+1 for Smitty Post 5

Heat gun to warm up (Loosen any potential Loctite).
Use Torx Number 27 screwdriver or socket (The right tool for the job).
Tap the inserted # 27 with a hammer, while the # 27 tool is installed in the screw head.
Then remove (counter clockwise direction) the screw.
May require a second heat up.

Good luck, you are not alone in derby cover screw stories.

 

I have used my rechargeable impact driver to remove these before with good success.
As mentioned earlier, make sure you use the correct size torx bit or you'll be drilling into the bolt head to get it off.
Good luck!

 

It's galvanic corrosion between the screws and the aluminum. I got mine out with an impact gun but if they're corroded enough, you're going to have to get draconian. Use antiseize and new screws when you put them back in, and don't leave them in there for years on end without removing them.

 

If you use an impact, be careful. I tried that and the T27 bit broke and the spinning remainder of the bit scratched the heck out of my primary cover before I could let off the trigger.

 

Great advice!