Slide drive shear pin fixed - New Horizons 5th wheel

Wayne

Wayne

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Staff member
When we were picking up to leave Austin a couple weeks ago, while I was closing the dining room slide, the shear pin broke on the front to rear drive mechanism. There is a hydraulic cylinder that operates the front slide arm, while a gear on the front slide arm drives a square shaft that powers a gear on the rear slide arm. There is a shear pin on the front gear axle where it engages the square shaft.

I believe the shear pin broke because the arms got slightly out of time when the hole in the drive tube started to elongate. This caused the rear slide arm to bind and drive hard, shearing the pin.

The shear pin has broken twice, of course at the worse possible time. I get under the trailer and turn the square drive shaft with a wrench and my wife keeps the front of the slide even by pushing the button to run the front cylinder. It's a good time.

The sheared pin is accessed by removing this access cover on the belly of the trailer.

IMG_6375.webp


You stick your head and torso up into the underside of the trailer while standing on your knees. The shear pin fell out of the hole when it sheared.

IMG_6367.webp


1/4" bolt. Of course it broke at the beginning of the threads:

IMG_6377.webp


This is the area I was working in. There is plenty of room to work, but there is lots of insulation dust to breath. The potable water tank is visible.

IMG_6367.webp


I replaced the 1/4" bolt with a 8mm bolt for a bit of added strength. I had to slightly ream the square shaft and the drive axle holes so the 8mm bolt would fit. If a bolt shears in the future, then it should be the rear bolt that is easy to get to from the outside. Either the factory bolt or the replacement bolt was too long and it hit the cylinder, which probably contributed to it breaking.

New bolt installed with a lock nut.

IMG_6369.webp


Rear slide arm with shear bolt visible.

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RV means ruined vacation.
surprised it doesn't have a hydraulics driving both sides..and the rack and gear is just for tracking...

you ever lube the slides? they get sticky and start to bind where they slide on different areas around the slide itself because it seems that the same thing has broken more than once, something is wrong... not saying people dont have problems with slide outs but I've never had any that a can of WD40 and a good cleaning of the mechanisms wouldn't cure.
 
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MSCH said:
RV means ruined vacation.
surprised it doesn't have a hydraulics driving both sides..and the rack and gear is just for tracking...

you ever lube the slides? they get sticky and start to bind where they slide on different areas around the slide itself because it seems that the same thing has broken more than once, something is wrong... not saying people dont have problems with slide outs but I've never had any that a can of WD40 and a good cleaning of the mechanisms wouldn't cure.
Click to expand...
From the peanut gallery, wondering if garage door rail lube might be a good way to lube rail slides. It is reported garage door lube does not attract or retain dust, dirt, or grime.
 
GON said:
From the peanut gallery, wondering if garage door rail lube might be a good way to lube rail slides. It is reported garage door lube does not attract or retain dust, dirt, or grime.
Click to expand...
I know its best to use something that doesn't attract dirt.
I do know its best to clean the undersides and the mechanism as good as you can
I've used WD40 on the sides and bottom of the slide out as well as the mechanism.
 
MSCH said:
surprised it doesn't have a hydraulics driving both sides..and the rack and gear is just for tracking...
Click to expand...
I would prefer that, but that's not how the slide arms are designed.

MSCH said:
you ever lube the slides? they get sticky and start to bind where they slide on different areas around the slide itself because it seems that the same thing has broken more than once, something is wrong... not saying people dont have problems with slide outs but I've never had any that a can of WD40 and a good cleaning of the mechanisms wouldn't cure.
Click to expand...
Yes, see this post: https://rvthe.us/community/threads/dry-graphite-spray-lubricant-for-slides.378/

I believe the slide was binding because the timing was off due to the broken bolt and slotted torque tube.
 
GON said:
From the peanut gallery, wondering if garage door rail lube might be a good way to lube rail slides. It is reported garage door lube does not attract or retain dust, dirt, or grime.
Click to expand...
Dry spray-on graphite is the answer, but do not get it on your clothes, because you won't get it out.
 
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Wayne said:
I would prefer that, but that's not how the slide arms are designed.


Yes, see this post: https://rvthe.us/community/threads/dry-graphite-spray-lubricant-for-slides.378/

I believe the slide was binding because the timing was off due to the broken bolt and slotted torque tube.
Click to expand...
yeah I know it depends on design. Honestly never looked at both of my previous RV's under there just because the stuff always worked... I'm assuming both your slides move simultaneously with the set up you have, I think my Cedar Creek was like that, but the Bighorn I have there is only one control with dual hydraulic cylinders and they operate independently from each other..I'm assuming there is some type of limit switches on them.

I'm just sitting here thinking to myself I have owned 3 different RV's with slides and never had any issues with them, and you said the shear pin broke twice on what is a relatively new unit, which leads me to think something else must be going on... you will know if it breaks it again..
 
Wayne said:
No, all three slides move independently.
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three separate switches and three separate systems.. that works. I wish mine was like that but it is what it is..

I'm not 100% happy with the Bighorn setup simply because you can't operate one slide only in the living room... which is handy in a rest area or tight space.

the bedroom is separate entity but the opposing slides in the main room work together but somewhat independently of each other....
 
Wayne said:
Yes, the new bolt is grade 8, while the old bolt was grade 3.
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Wayne are you sure this is a good idea? A shear pin breaking is a sign of another problem. If you use the grade 8 bolt the weakest link might be a more expensive part. That said moi don’t understand your problem.

Just my $0.02
 
tnt_motorsports said:
Wayne are you sure this is a good idea? A shear pin breaking is a sign of another problem. If you use the grade 8 bolt the weakest link might be a more expensive part. That said moi don’t understand your problem.

Just my $0.02
Click to expand...
I'm sure the broken shear pin was caused by the slide being out of time due to the shear pin elongating the hole in the torque tube, causing the slides to bind. The reamed hole and the larger bolt will fix the timing issue. There is a second shear pin on the other end of the torque tube that is now the weakest link. I'd prefer that one shear as it's simple to change.
 
MSCH said:
ever wonder why they went to a "touch" screen when simple switches would suffice?
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Almost all lights, the slides, and the generator are controlled by the touch screen. It's just how New Horizons does things.
 
Wayne said:
Almost all lights, the slides, and the generator are controlled by the touch screen. It's just how New Horizons does things.
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its not just them.. it is everybody and everywhere... my latest ceiling fan at home came with a remote control.. dumbest shi+ I ever seen but OL said they dont even have the regular old type anymore at Home Labrynth..
its all bling designed to create wet panties so easily impressed gadget freaks open their wallets
and not pay attention to the flaws in the overpriced piece of crap they use to go RVing


you ever think to yourself just because they could do something, they didn't have to? :)
 
MSCH said:
you ever think to yourself just because they could do something, they didn't have to?
Click to expand...
Yes, I work with operating systems in routers. Just because the feature is there, doesn't mean you should use it....
 
MSCH said:
its all bling designed to create wet panties so easily impressed gadget freaks open their wallets
Click to expand...
He's looking right at you Mr. CTBob with your blingy solar system with all the controls and data screens and whatnot.
 
Wayne said:
Yes, I work with operating systems in routers. Just because the feature is there, doesn't mean you should use it....
Click to expand...
maybe for me I value simpler stuff without a reliance on computer chips, touch screens and wires
especially where there was no need for them.
 
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