Electric landing gear motor straining and "clicking".

[JimHamlin]

Well I've read most of the posts regarding electric landing gear problems, and have proceeded to take mine apart to see if I can discover the cause of a slow, straining motor along with a clicking sound when in the lift mode. My 3400 Bighorn 5th wheel is now on jacks, but the last time I tried leveling it, I felt the motor and it was hot to the touch. The pin weight is approx 2500 to 2700 lbs. At this point I've taken the driven side apart, not just to visually inspect but to make sure the jack screw was adequately lubricated. The gears look in reasonable shape, and the jack screw appears to have some amount of a grey lube all around and thru the whole length. At this point I'm thinking I either have a failing motor (I understand there's an internal clutch - is this true??), or the driven-side may be binding thru bad gears or no lube. If you were at this point of troubleshooting, what next steps would you take? I'm not suspicious of wiring, since the motor, heating up as it does, obviously is consuming plenty of wattage. While the rig is on jacks, I do plan to disassemble and inspect the curb-side mechanism - just to eliminate the possibility that it's gears are somehow failing. If everything looks good there, I guess it all points to the motor?? Many thanx in advance for any comments/suggestions you might have. Oh, forgot to mention - I initially checked for a breaker problem by substituting with a 50a breaker, and witnessed no difference in symptoms.

Jim

 

[danemayer]

I initially checked for a breaker problem by substituting with a 50a breaker, and witnessed no difference in symptoms.

I might be wrong, but I thought the electric landing jacks were on a 30 amp circuit.

 

[JimHamlin]

Thanx for your quick response Dan. Yes, the system uses a 30a breaker. I just substituted with a 50a breaker I happened to have, to confirm the old 30A wasn't defectively kicking in and out, thus causing the "clicking" sound coming from the motor. I have since replaced the original 30a breaker.

 

[JohnDar]

A weak battery will also cause problems. Does it still click and labor when connected to shore power or the tow vehicle?

 

[wdk450]

I don't know how much you want to spend, but you may want to upgrade to dual motors: https://www.strombergcarlson.com/fifth-wheel-landing-gear/dual-power-conversion-kits/

 

[JimHamlin]

Re: Electric landing gear motor straining and "clicking".

Don't think it's a battery problem. I had a digital VM across the batteries when I last tried it. They read 13.4V before starting, and after 2-3 minutes of operation it read 13.1. That's when I felt the motor and found it quite hot.

- - - Updated - - -

Well I'll definitely do this as a last resort, however the single system I have operated properly until recently. Tells me SOMETHING changed.

 

[caissiel]

Check the torque required by using the manual crank.
Mine was hard to turn and almost bend the crank.
The centering plate was moving pushing the gears apart causing drag.
Some use a heavy pipe clamp to hold the plate pn center.
3 last unit needed modes.

 

[JimHamlin]

Funny you should mention that. I did try once to manually crank the rig up, and found it nearly impossible. Is the "centering plate" what's supposed to keep the jack-screw and attached gear in place? I plan to clean up all the parts, than temporarily reassemble and see if I can validate that that's what's been happening. Any idea where I'd find a "pipe clamp" you mentioned? I did see a photo of what you used, in one of your previous posts. Thanx again for your quick response!

 

[123camper]

We had this same problem with our sundance and after doing everything you have done I found we had a bad switch


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[Gary521]

I recommend that you check the other leg but also add a second motor.

 

[JimHamlin]

Thanx for your comment. I did finish lubing, reassembling and reinstalling the roadside leg, and saw no evidence of binding or excessive slop between the gears. And the centering plate seemed to be working right, stabilizing the jack screw. As you say, the curbside is next!

 

[jolar3329]

When the same thing happened to me it was the gear box that was defective. If both jacks are not in sync to lift the load it over strains the gear box case.

 

[JimHamlin]

Thanx for your comment, I'll be sure both jacks are in synch after I inspect/lube the curbside leg. I ran the gearbox with 12V and no load, and it sounded ok.

 

[JimHamlin]

Well after disassembling, cleaning and lubing both legs, they both work! I did find that the curbside gears were binding somewhat and didn't have enough clearance between them. Not being sure what caused this (if I was an engineer I'm sure I'd know!), I just substituted a thinner thrust bearing for the original - less than 1/16" thinner. This seemed to result in adequate slack between the gears. I wasn't sure that all my actions were going to solve the problem, and was ready to order a new motor and reduction gearbox. Not sure if this will be a permanent fix, but we'll see. My only other observation is that this OEM setup is marginally adequate to handle 2,500-3,000 lbs. Perhaps the dual-motor upgrade will be the eventual solution. Many thanx for all who chimed in to help out. Makes it so much easier to handle situations like this, that you've not dealt with before.