Stillwell Store and RV Park Porch Big Bend TexasIf you gotta be stuck hanging out on a hot porch in the middle of nowhere waiting for UPS to show up with parts you need for an RV repair, there is no better place than the Stillwell Store. But more about that later.

This post is intended for anyone who wants to save the expense of a trip to the RV shop after discovering their landing gear (AKA: Front Legs, Leveling Jacks, Etc.) may be malfunctioning. Specifically, I shall address how to replace the gearbox on the DC motor that powers the landing gear on our Arctic Fox 24-5N fifth wheel trailer.

Diagnose the Problem

Puuurrrrrrrrrrrrr, chunk, chunk, purrrrrrr, chunk, purrrrrrrr, chunk, chunk! Chunk-k-k…

Don’t let your gearbox get that bad. The first time you hear something like this when extending the legs on your fifth wheel when unhitching, or hitching up, investigate further, immediately. Upon hearing such a noise, watch the motor as you extend the legs. If the motor assembly dances about in tune with the chunkity chunk chunk, the gearbox is probably going bad. The good news is, the gearbox can be replaced without having to replace the motor.

Find the Right Parts

Fifth Wheel Trailer Landing Gear DC Motor GearboxNorthwood Manufacturing has always been very helpful in answering technical questions and troubleshooting any issues we have had with our Arctic Fox, which was manufactured at their facility in La Grande, OR. But when it comes to ordering replacement parts, they suggested I contact our dealer. Understandable, but interesting, considering our package was was shipped from La Grande. They did however help me identify the replacement part I needed.

Apache Camping in Portland, OR was also helpful in getting us the part we needed. Even if it did take a couple days of email communication since we are without cell phone service here at the Stillwell Store.

For our 24-5N we needed the gearbox that attaches to the Venture 9000PK 12v DC 30 Amp motor that drives our landing gear.

Fifth Wheel Trailer Landing Gear DC Motor Gearbox

How to Replace DC Motor Gearbox

On our 24′ Arctic Fox the DC motor that drives the landing gear is clearly visible inside an outer compartment. Thankfully, this makes it easily accessible for maintenance. I took the following steps to replace our gearbox, and offer a few tips and precautions below to help anyone who may need to do the same.

1. Remove the retaining bolt from the sliding sheath on the square shaft that drives the opposite leg. Slide the sheath back to expose the gearbox drive shaft that powers leg movement.

TIP: I keep a few of these bolts on hand as they can vibrate loose and disappear, causing a panic attack and the need synchronize your front leveling jacks.

Fifth Wheel Trailer Landing Gear DC Motor Gearbox

2. Remove plastic retainer that secures gearbox onto drive shaft so motor assembly can be removed from leg. A small screw holds this in place.

Fifth Wheel Trailer Landing Gear DC Motor Gearbox Repair

3. Slide gearbox with motor attached off the drive shaft, moving the shaft to opposite leg aside as necessary. The manual override drive shaft attached to the gearbox will easily slide out of its housing.

NOTE: If your motor has ample wiring attached, there is no need to disconnect any wires. Simply rest the motor with wires still attached on the compartment floor or a table outside the door. If you must disconnect wires, be sure to mark them for easy reference.

Fifth Wheel Trailer Landing Gear DC Motor Gearbox

4. Remove DC motor from the attached gearbox.

NOTE: Four bolts attach the motor to the gearbox, but only the two long bolts need to be removed. If you do remove a short bolt, replace it to keep the motor intact and remove the two longer ones.

Fifth Wheel Trailer Landing Gear DC Motor Gearbox

5. Note the alignment and position of the gearbox as you remove it, and replace it with the new one.

6. Re-attach the motor assembly onto the drive shaft by moving the opposite leg shaft aside and inserting the manual override shaft into its housing. Then align the center drive nut of the gearbox onto the drive shaft.

NOTE: Consider fitting the gearbox alone onto the shaft first to ensure a proper fit!

I neglected to do so, only to discover that the new gearbox fit extremely tightly on the drive shaft. I remedied this by removing the motor from the gearbox so I could more easily force it into place, then re-attaching the motor.

Fifth Wheel Trailer Landing Gear DC Motor Gearbox Repair

7. Activate landing gear switch (or use manual override wrench) to properly position the screw hole in the drive shaft so you can re-attach the plastic retainer.

NOTE: Synchronize leg length before reattaching opposite leg drive shaft!

Fifth Wheel Trailer Landing Gear DC Motor Gearbox Repair

If you have moved the motor after attaching the gearbox to the leg, ensure that both legs are the same length before proceeding. Measure the distance from the frame to the lower end of the sliding section on the opposite leg, and extend or retract the leg with the motor attached to match.

8. Re-attach the opposite leg drive shaft, adjusting the drive shaft as needed to align the bolt hole by activating the landing gear switch slightly, or using the manual override wrench.

9. Secure the opposite leg drive shaft with the retaining bolt.

Hopefully you have no parts left over, and when you test the motor the gears purr like a kitten without any chunky noises or dancing about of the motor.

Preventative Maintenance to Avoid Landing Gear Repair

After full-timing for more than five years, damage to our well used gear box is to be expected. Northwood, however, informed me that over-extending the legs can cause extra stress on the gearbox potentially damaging the gears. Interestingly enough, I dissected our old gearbox with the idea of getting a picture of some damaged gears, but everything appeared to be intact. I was reassured, however, to hear that the the landing gear motor rarely goes bad, and my assumption that the gears were going out was correct. I kept my old one for spare parts just in case.

NOTE: Never over extend the landing gear on your trailer!

When I inquired if there could be anything within the leg itself causing the issue I did discover one more rather alarming precaution. Over-extension can cause a mechanical failure inside the leg resulting in total inoperability, which can only be fixed by replacing the entire leg… not something you’re going to do by yourself in the middle of the desert!

All Feedback Welcome

Did you find this post useful? Please feel free to comment with your own helpful tips regarding this repair, or provide advice for doing similar jobs on different trailer types.

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15 Responses to “How to Replace DC Motor Gearbox on Fifth Wheel Landing Gear”
  1. Dennis says:

    Have replaced my gearbox and put new gears in both legs,Atwood brand but still has the issue raising it up,only when it gets the weight will it start making that noise.

  2. phillip allen says:

    need to replace landing motor and gear, the gear on my 1996 electra 5th wheel the shaft coming out of gear is round not flat on one side. gear housing is open not inclosed like the one I bought. any help out there on this problem.

    • Jim says:

      Good luck with that Phillip, sounds like our landing gear units are quite different. Sorry, I offered the best help I could in the steps above.

  3. pete says:

    I CAN’T THANK YOU ENOUGH JIM,MY 2009 KEYSTONE COUGAR HAD A BUSTED LANDING GEAR HOUSING WHEN I BOUGHT IT AND I DIDN’T KNOW IT.I HAD HEARD HORROR STORIES OF BENT SHAFTS AND MY RV MECH DID NOT WANT TO TOUCH IT,WITH OUT HITCHED TO THE TRUCK I CHANGED THE GEAR BOX OUT IN 45 MIN!VERRRY COOL,HEADING OUT FOR JUNE LAKE IN MAY,CAN’T WAIT.

  4. Alex Gross says:

    Jim, I was reading you article on changing out the gear box on the front landing gear from 2012. My question is…..Can the landing gear support the 5th wheel while the gear box is being replaced?

    Thanks…..

    • Jim says:

      Good question! I did the repair while still hitched up to the truck, but I don’t see why not. The legs will support the trailer unless the teeth on the leg itself are stripped way down, which I sincerely doubt. The only challenge may be aligning the motor gears since it may be tight due to the added weight. But the manual override could be used for slight adjustment if necessary.

      Thanks for asking and good luck!

  5. Kamper Dave says:

    Great article! Thanks for taking the time to help others and for the preventative tips. I went out and marked our landing gear legs to prevent over extending in either direction. It seems amazing to me that such a small contraption can safely perform such a big task.
    We give our landing gear a workout as we tow nose-high. The poor landing gear needs to lift the pin off of the hitch and lower the unit way down to a level position.

  6. DAVID says:

    To change gearbox out, can the legs be supporting the 5thwheel or does weight have to be off?
    Thanx
    Dave

  7. Dan says:

    I like that most of these things are accesable and can be fixed. My wife and I are looking at the smallest 5th from Northwood, now 28′-6″ long, and going fulltime in a couple of years. Right now we use a restored 13′ scamp and have a great time. I have been going over your blog and like your attitude toward life on the road. It’s nice to see some else that doesn’t need a huge trailer to enjoy the life. Have a great day.

    • Jim says:

      Thanks for the comment Dan, and best wishes for your upcoming adventures! We have been very happy with our 24′ Artic Fox from Northwood, but if you ask Rene she would likely tell you that 28′ would be the perfect size.

    • Rene says:

      Dan, thanks for reading and commenting! I saw that Northwood wasn’t making our rig size anymore, so now I guess we have a collector’s item! When you go from the Scamp (cool trailer!) to a bigger rig it’s going to feel like a mansion. Sweet. I do love our rig but sometimes just wish it had a little more room so I can do yoga without banging my head on the table, and add one more dog to our pack. Otherwise though, staying smaller has really helped us go so many places off the beaten path that we wouldn’t have been able to otherwise.

      Keep us posted on your upcoming adventure! Good luck!

  8. Great write up, guys. What year is your fox, again? Ours is a an 2008. Our slide-out motor burnt out (with the slide out and motor seized) two months ago, right as we were paying for our first campsite in years. It was in Joshua Tree NP. I really wanted to camp within a few feet of where we were climbing. I guess the camping gods were paying us back for paying in. We barely got any climbing in because we were working on it. We ended up tearing it all apart and driving to RTR with the slide strapped in (literally), being careful of sharp left turns. We had hoped to buy a new one in Q. All we found were $800+ ones. Thankfully Johnny, with help from Don at Raven’s Roads, rebuilt ours at no cost. It’s nice when you can fix the broken in comfy campsite. Oh! The joys of home ownership, right? It’s always better when you can work on things yourself. And, doubly so when someone provides a walk-thru as you did. Cheers!

    PS. how far east are you planning to go this year? Heading to Florida to join the other NuRvers?

    • Jim says:

      Thanks for the comment! Our fifth wheel is a 2007 24-5N. We won’t be heading east this season, actually heading back north to the mountains now…

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