Bolt Sheared Off on Slide Rod

[10forty2]

So, I guess the "age" demons are playing with us on our new (used) coach (1999 model). Nothing major, but we noticed that the living room/kitchen slide went out one-sided....we could get it to go out completely and evenly without much effort by pushing. After looking around along the side and under the slide, lubing everything good, and finally looking in the basement at the mechanics, I found the bolt had sheared off that holds the rod to the gear on the rear side of the slide. Not sure what could have been binding to cause it to shear off, but there it was, clear as day...a broken bolt. So now, I am on the hunt for a grade 6 bolt (what came out of it) and then to figure out how to align the bolt holes without disconnecting the entire rod. Should be interesting. Any tips??

[eheading]

Regarding the class 8 bolt. We had a similar problem with a Power Gear slide on a Fleetwood Revolution LE. I called Fleetwood, and the Class 8 bolt is exactly what they specified. A softer bolt will shear too easily, and a harder bolt will not shear, but something else may fail instead. So from the information I have the advice to get the class 8 bolt was "right on".

Ed Headington

[10forty2]

John Wayne wrote:
If it's a power gear there should be a lever on the motor (which is the brake) You can move this lever and you may be able to move the shafts with a pliers. This is also the way you manually push the slide out in if you need to ( motor gives up). Just remember to move the lever on the motor back when done.

Ding, ding, ding!!! We have a winner!! THANKS!! Yep, found that lever, and was able to easily move the shaft to align the bolt holes...BUT.... in my infinite wisdom I bought longer bolts to make sure that the shoulder/collar (whichever it's called) would take the "shear" force, but ......they are now too long to make the rotation without the end of the bolts hitting the underside of the floor of the slide. Soooooo.....I'll go back and get the original length and hope that I've eliminated whatever bind caused the bolts to shear in the first place and there won't be a problem with the force being on the threads of the bolts. 🙂

Gotta love whoever engineered this........

[John_Wayne]

If it's a power gear there should be a lever on the motor (which is the brake) You can move this lever and you may be able to move the shafts with a pliers. This is also the way you manually push the slide out in if you need to ( motor gives up). Just remember to move the lever on the motor back when done.

[10forty2]

Pass42 wrote:
What did the cross section of the broken bolt look like??? Less than 2% of fastener failures are from shear forces......However, over 88% are from Fatigue failures.... which will yield a relatively smooth failure face, normally with "beachmarks" on it...like the lines on a beach from the waves...
I've been involved with fasteners for 35 years, including presenting over 350 fastener seminars to mechanics & engineers......

I didn't really look at it that closely, so I have no idea. It was broken below the collar on the threaded part, though. The bolts I just bought are longer to make sure the collar takes the force and not the threads.

Is there a way to turn the gear without moving the slideout section? That sure would make it easier to line up the bolt holes with the square tubing rather than having to have someone inside bumping the motor switch until it lines up.

[Pass42]

What did the cross section of the broken bolt look like??? Less than 2% of fastener failures are from shear forces......However, over 88% are from Fatigue failures.... which will yield a relatively smooth failure face, normally with "beachmarks" on it...like the lines on a beach from the waves...
I've been involved with fasteners for 35 years, including presenting over 350 fastener seminars to mechanics & engineers......

[10forty2]

Executive wrote:
My first question would be how your maintenance has been with the slide? Do you lube it regularly of just let it move in and out? It may simply be a case where the slide has started binding due to lack of maintenance and the bolt sheared off to prevent further damage to the motor and mechanisms. I would replace it with the exact bolt that sheared off.....Dennis

We literally just purchased the coach and brought it home this past weekend from an elderly couple that couldn't use it anymore due to health issues. I would say, though, that their maintenance was regularly performed since they included 3 cans of slide lube and emphatically instructed me to make sure I sprayed it on the gears and rails before pulling the slide back in after a trip. I doubt it was neglect that caused the bolt to shear, but rather the bolt got loose and caused it to break. Once I replace the broken one, I'll be torquing the others to be sure!

[mfox20]

I have a 2000 HR Endeavor Gasser and had the same issue with sheared bolts. Mine also had a couple of broken teeth on a drive gear which would cause the slide to skew and that extra strain would break the bolts.

I just replaced bolts a few times and carried spares until I figured out the broken gear problem. Had not had any problems since replacing the gear.

Agree with John Wayne also...need to check the bolts once in a while because they will shear pretty quick when loose.

[John_Wayne]

The bolt gets loose and then breaks. I think he shear pin (roll pin) in the gear is the safety item. Then bolt is just a bad design as you are putting a square tube over a round rod and there is play between the two. Bolt gets loose breaks off.

[Executive45]

My first question would be how your maintenance has been with the slide? Do you lube it regularly of just let it move in and out? It may simply be a case where the slide has started binding due to lack of maintenance and the bolt sheared off to prevent further damage to the motor and mechanisms. I would replace it with the exact bolt that sheared off.....Dennis

[Bugman114]

You might want to see if there might be something in the mechanism itself that's binding. Unless it's just a poor design that puts a huge load on that bolt, it takes a lot of force to sheer a grade 8 bolt. Maybe someone wanting to ride the slide out, lol. I've never actually had slide outs myself so I don't know what the do's and don'ts are, just a theory

[10forty2]

rgatijnet1 wrote:

fcooper wrote:
If this is where the square drive rod mates to the round rod on a powergear electric slide, you want to find a grade 8 bolt long enough so that the shoulder of the bolt covers both areas where the shear stress is located. It's ok to use a few washers on the threads if required as long as you have clearance.

Once you find the right bolt, buy a few spares.

Realignment is fairly easy. Get the slide fully extended and use a large crescent wrench on the square tube. You should be able to flex it enough to allow the alignment and get the bolt/nut installed. I've had several break until I learned about the grade 8 bolt with the shoulder long enough to keep the threaded portion away from the shear stress area.

Fred

Fred,
I'm not familiar with the system but are you sure that it is a good idea to install a beefier bolt in a location that is supposed to "shear" if there is an obstruction? Isn't that like putting in a larger fuse in an electrical circuit? Perhaps if the bolt shears off, if it was designed that way, it is to protect from greater damage if it does not shear.

That was going to be my question... isn't the bolt SUPPOSED to be a shear point in case something gets in a bind? I'll try Fred's suggestion about using a crescent wrench to turn the shaft a bit to align the bolt holes, but I think I'll stick with the grade 6 bolt that came out of it.

**EDIT** Went back and looked at the bolt...it is a grade 8 bolt that was in it, so I'll replace it with a grade 8!

[rgatijnet1]

fcooper wrote:
If this is where the square drive rod mates to the round rod on a powergear electric slide, you want to find a grade 8 bolt long enough so that the shoulder of the bolt covers both areas where the shear stress is located. It's ok to use a few washers on the threads if required as long as you have clearance.

Once you find the right bolt, buy a few spares.

Realignment is fairly easy. Get the slide fully extended and use a large crescent wrench on the square tube. You should be able to flex it enough to allow the alignment and get the bolt/nut installed. I've had several break until I learned about the grade 8 bolt with the shoulder long enough to keep the threaded portion away from the shear stress area.

Fred

Fred,
I'm not familiar with the system but are you sure that it is a good idea to install a beefier bolt in a location that is supposed to "shear" if there is an obstruction? Isn't that like putting in a larger fuse in an electrical circuit? Perhaps if the bolt shears off, if it was designed that way, it is to protect from greater damage if it does not shear.

[fcooper]

If this is where the square drive rod mates to the round rod on a powergear electric slide, you want to find a grade 8 bolt long enough so that the shoulder of the bolt covers both areas where the shear stress is located. It's ok to use a few washers on the threads if required as long as you have clearance.

Once you find the right bolt, buy a few spares.

Realignment is fairly easy. Get the slide fully extended and use a large crescent wrench on the square tube. You should be able to flex it enough to allow the alignment and get the bolt/nut installed. I've had several break until I learned about the grade 8 bolt with the shoulder long enough to keep the threaded portion away from the shear stress area.

Fred

[Jerallen]

Mine had a split pin that snapped on the slave slide. I was able to align using a pipe wrench on the shaft.