Power Steps - Lippert - Grinding at Retract?

[pconroy328]

This is a new one on me - the steps now grind at full retract. Lippert Kwikee Steps

I've had 'em grind at full extend before. Any suggestions on where to start on a fix?

https://photos.app.goo.gl/hmapojBP98yZ3n6b9


Thanks!

[dougrainer]

Chum lee wrote:

dougrainer wrote:

RLS7201 wrote:
Correct, the gear does not come individually. It comes with the 3 cushions.

Gear

Richard

Thanks. That is a alternate source. Not Kwikee(LCI). Was not available a few years ago. For $16, safe bet to try. Doug

Yes. When I repaired my 1999 Series 32 steps that had similar issues (with an upgrade kit) in 2015, that gear was not available, and, believe me, I looked. It wouldn't have helped me anyway because the large die cast metal reduction gear inside the main gearbox is what exploded on mine. I do mean exploded. It was in five pieces inside the gearbox and the steps swung freely in the air. They would not extend or retract fully.

IMO, if your broken Kwikee stairs are +15 years old, replacing one gear in the drive train makes as much sense as replacing 1 broken link in an old worn out bike chain.

Chum lee

As a Professional RV tech, these forums help me find obscure parts that are not easily found on RV part supply systems. Finding these type parts help me save customers money. Doug

[Chum_lee]

dougrainer wrote:

RLS7201 wrote:
Correct, the gear does not come individually. It comes with the 3 cushions.

Gear

Richard

Thanks. That is a alternate source. Not Kwikee(LCI). Was not available a few years ago. For $16, safe bet to try. Doug

Yes. When I repaired my 1999 Series 32 steps that had similar issues (with an upgrade kit) in 2015, that gear was not available, and, believe me, I looked. It wouldn't have helped me anyway because the large die cast metal reduction gear inside the main gearbox is what exploded on mine. I do mean exploded. It was in five pieces inside the gearbox and the steps swung freely in the air. They would not extend or retract fully.

IMO, if your broken Kwikee stairs are +15 years old, replacing one gear in the drive train makes as much sense as replacing 1 broken link in an old worn out bike chain.

Chum lee

[MrWizard]

I do believe i let my old age catch up with me, and confused two different gear Assemblies, i talked about a 90+ degree shaped gear when i
When i should have been talking about a circular gear, but other wise correct , broken teeth cause the non stop motor run on, and the noise , replacing the swing arm gear box assembly, gives the best results, all new parts and bushings with no wear that give it back the like New smoothness of action

[MrWizard]

On the steps i have repaired, To visually inspect the gears, you have to remove the motor assembly & swing arm drive box assembly, and open the swing arm box assembly, or at least stick a screwdriver into the slot of the assembly input shaft, and turn it back and forth to each end of travel movement and feel for the stopping or gear rattle as it keeps spinning, is that what you did ?
Looking at the swing arm on the exterior of assembly will not tell you the condition of the gears, the motor assembly has gears, and the swing arm box has gears, and all are hidden from sight, when the motor assembly is removed from the swing arm gear box , the output shaft will spin continuously when power is applied to the motor ,
The swing arm gear box has limited motion, the output shaft of the motor assembly is a slotted fit into swing arm box assembly, a small gear in the assembly meshes with the larger shaped 90° gear which rotates the shaft the swing arm is attached too, this where the break occurs, missing teeth on the 90° partial gear at the full retract position, and you get the rattle and motor spin at the top of retract, if teeth on the little full circle input gear, wear or break, you will also hear a skip bump while the step is retracting,
The fix, is a New swing arm assembly box,
The plastic gears break when under an impact stress, this can mean less damage to the step assembly and a less costly repair,
If the step operates normally when being extended, its a near 100% probability of damaged gears in the swing arm box,
The large limited motion gear is actually a bit more than 90° but a lot less than a half circle 180° gear that one would expect to find inside, calling it 90° is just easier

[dougrainer]

RLS7201 wrote:
Correct, the gear does not come individually. It comes with the 3 cushions.

Gear

Richard

Thanks. That is a alternate source. Not Kwikee(LCI). Was not available a few years ago. For $16, safe bet to try. Doug

[RLS7201]

Correct, the gear does not come individually. It comes with the 3 cushions.

Gear

Richard

[dougrainer]

https://www.rvupgradestore.com/Kwikee-Electric-Step-Repair-Kit-p/44-8127.htm

For a step 15 years old, I would purchase the upgrade kit, rather than spend money on individual parts. If you drop the motor, you will probably find the large internal gear inside the gear box has a busted tooth. THAT part they do not sell individually. Yes, the motor stops from the rise in amp draw the controller senses when the step stops moving. Doug

[dougrainer]

CWilson wrote:
The entire situation can be summed up in one word.

LIPPERT!


Good luck.

LCI did not own Kwikee in 2008. Doug

[pconroy328]

Sorry - got busy. That bent screw was just something I grabbed to do the testing. The steel pin is a bit of work to get in and out, so I just grabbed something long, narrow...

It's made from Chinesium, so that's why it bent.

I crawled under, everything looked fine. No broken teeth. Someone else said the controller uses current sensing to know when to stop the retract. It sure sounds like it's not sensing the current increase.

[MrWizard]

I noticed that nice long screw you have for the step up/down connector pin,
In the past did the steps get impacted against the curb or some other object ?
When that happens the force is excerted on output gear as it trys to make the motor turn, and the gear teeth get damaged, after that it just a matter of time (use cycles) to when the damaged teeth break,
It has happen to me , it happens to many of us,
From the rock we didn't see or curb that was too high etc

[pconroy328]

MrWizard wrote:
I think he means look to verify broken or not,
Motors are available
Gear boxes are available
Replacing old motor with a new replacement version can also mean modifying the wiring, the last motor i replaced did not have the same connections as the one i removed, replacing the controller usually requires replacing the door sensor switch, because the controller circuit has changed to sense a different switch connection,
One is a switch that closes AKA when the magnet is near, one is switch that opens when the magnet is near, I'm not sure which one is the old design and new design,
I think closed when magenta is near AKA normally open switch is the old style, but i can't swear to that,
Anyway the controller is not the OP's problem

Yessir - you are correct. Another person told me the controller uses Current Sensing to determine when the motor has reached it's limit/end stop. So broken or worn teeth might be the issue.

It's a nice day today so I'll ruin it by crawling underneath the beast and yanking stuff off. 🙂

[CWilson]

The entire situation can be summed up in one word.

LIPPERT!


Good luck.

[MrWizard]

I think he means look to verify broken or not,
Motors are available
Gear boxes are available
Replacing old motor with a new replacement version can also mean modifying the wiring, the last motor i replaced did not have the same connections as the one i removed, replacing the controller usually requires replacing the door sensor switch, because the controller circuit has changed to sense a different switch connection,
One is a switch that closes AKA when the magnet is near, one is switch that opens when the magnet is near, I'm not sure which one is the old design and new design,
I think closed when magenta is near AKA normally open switch is the old style, but i can't swear to that,
Anyway the controller is not the OP's problem

[Chum_lee]

pconroy328 wrote:
Thank you MrWiz... Everything is well lubed, no binding. Motor grinds with at the same spot with no load, with steps disconnected.

It's like it doesn't know it's at the limit and keeps pulling.

I guess yanking the motor and looking for some broken teeth is next.

Don't bother looking for broken teeth. Even if you have/find them, (for most people) the gears they attach to aren't individually readily available in the aftermarket. Most likely, you'll be needing a motor/gearbox/controller upgrade/update which is readily available. You can buy a new motor, a new gearbox, or, a new controller, or an upgrade kit containing all three. Google is your friend. You'll need the year, the step series, and possibly the chassis which these Kwikee step upgrades will be attached to get the right parts.

Chum lee