This was quite helpful. The repair in this video was for the hold down for the "rack" (worm) gear. What I actually found on mine was that the roll pin that holds the PINION gear in place had had backed out about halfway. All I had to do here was push the roll pin back in place with my finger. I smeared some silicone RTV on each side to keep it in place. It doesn't need to be held down like the rack gear. It just needs to be kept from moving side-to-side. The RTV should do that fine. I didn't even have to remove the crank mechanism to do this repair. It took me longer to get the screws out of the screen and bezel than to fix the thing! One word of caution; the screws holding the screen in place are REALLY short. You'll probably drop a few of them while disassembling and reassembling. If you have floor vents in your rig, be sure to cover them up! Murphy's law dictates these screws will find those vents! After ALMOST losing a screw down one of those I put a dark-colored blanket on the floor beneath where I was working. This will limit how much the dropped screws will bounce before coming to a stop and make them easier to find.

Just what I was looking for. The right side screw holding the manual knob on screws into a piece of plastic that has broken away from the lift arm. I may have to glue it or tape it. Thanks for the dissembling instructions.

Thanks. This wasn’t exactly my problem but I saw how it comes apart and was able to reattach the arm to the opener. Happy travels.

This is exactly the fix that I was looking for, however, it took me forever to find it. I searched for "Fantastic fan gears stripped" and found almost nothing. That being said, THANK YOU! I'm going to check this out on my kitchen roof vent.

Thank you for your video - mine is a little different than yours, but I got the jest of it and was able to repair mine. I was sort of afraid to start taking things apart I knew nothing about, but after watching your video I took on the challenge and removed the 4 screws and it fell right down. I could tell right away that the bar that raises the lid had become disengaged from the turning knob so I guided it out of it's slot and found a nut and bolt to put them both back together again and slid the bar back in place and it work!!!!! I then took the knob off and put the cover plate back on and then the knob and it's back to working like new again. Thanks again for the video, it really helped...

Videos like these are invaluable and old school tech fixes. Nowadays, the younger generation believes in throwing out everything and replacing them with newer, more expensive and not necessarily better gadgets. I love videos like this. So helpful! This will enable me to fix that fantastic fan lift arm perfectly. Please note that music in DIY videos is an irritant to the viewer. Sounds like a good idea (pun intended), but not from the viewer perspective.

RIGHT ON MAN! THANKS!

Nice video of the whole assembly.

Very helpful, thank you.

Thank You soo much, I needed this Video

Hoping this does the trick, thanks, guys.

Well done video! My fans are more sophisticated than the one demonstrated, which may present more complications than your procedure. But my lid opens either via power or manually only 2 inches then falls back down. I suspect a stripped arm gearing although the drive pinion looks fine. But your video means I may now have an easier means of getting at parts than I thought. Thank you. And I’ll check out if that plug/insert has popped up and needs modifying as you describe. Addendum: found worn teeth on the base of the arm. Would include a photo if I could. Guess a whole new arm module is the fix.

thanks my bedroom one wont open this maybe my problem

Would you do a video on replacing the city water bypass valve, please? Your freshwater pump video was very useful. I'll be following this one shortly!

I know this video is old but I have that same type of vent/fan and I need to replace the vent cover but cannot find one for a side opening lid. Had you had to replace yours and, if so, where did you find one?

Thank you all

We have a Dometic vent fan 4100 model. Lift arm is plastic and broken of course. Can we replace it with a metal arm or are we just screwed by Dometic. Cannot find a replacement part online. Next stop Camper World 😮.

clever fix....you could have gotten the fan out of the way by removing one screw and pulled the fan.

I have the problem of the knob pull-down disconnect from the gearing popping out by itself and the motor then turning endlessly but not moving the vent cover. I bought a new vent arm for a reasonable price at RV Trailer Supply, in El Cajon, Ca. The new arm has the casting sealed except for a small (Oil?) hole on the bottom - the shaft is not free to move vertically like the presenter's was. Installed this new arm, and the problem remains. I guess the problem is in the motor/gear assembly which somehow has the detented up/down locking mechanism, which isn't obvious how to fix. This stupid little motor assembly is $50 or more everywhere I have searched. No videos o how to fix the motor. Any suggestions??? Your can fix looks good, but I would use a stronger food can instead of a weaker aluminum can, but again, i don't need that. The shaft in my new replacement lift arm is solidly encapsulated.

Did you ever have a problem of the fan not coming on when the lid opens???

Where do you buy the motor for the fan?

Just another part in the Thor Four Winds rv that goes dead. This video just proves how terribly aweful it is for a woman to fix. And I'm a machine girl.... After a few curse words I climbed up on a stool manually turned the black knob and WALLA, it worked.