Same shear bolt broke again. Second time in a little over 6 years on our 2007 HR Endeavor. It is the front bolt on the road side kitchen slide that has the frig, dinette and desk. That slide has to ride up over the tile floor rather than straight in like the other kitchen slide.At least this time in broke in the garage and not out on the road like the first time. Doesn't bind or make unusual noises. When the tech fixed it last time, he took multiple measurements to make sure that it was pulling square.The only possible issue that I can think of is we took the couch out of the slide and replaced it with a much lighter chair, stool and small desk. So, the slide end that keeps shearing the bolt is probably a couple hundred pounds lighter than original configuration. Can't imagine that would be an issue.Would like to hear from any of you HR/Monaco owners about any known issues.

You may have to increase the shear strength of the bolt. A constant amperage reading will reveal whether or not the slide action is free and correct for the entire length of travel. A sudden increase in motor load amperage is a dead giveaway that stuff is misaligned.

MEXICOWANDERER wrote:You may have to increase the shear strength of the bolt. A constant amperage reading will reveal whether or not the slide action is free and correct for the entire length of travel. A sudden increase in motor load amperage is a dead giveaway that stuff is misaligned.Good suggestion on the amps. I'll check the head of the bolt to see what grade it is and see about going up in strength.

Mite also check and see if the hole is egg shaped have heard this is also hard on the slide bolts. The fix is to re-drill the holes 1 size larger with a larger bolt.

John Wayne wrote:Mite also check and see if the hole is egg shaped have heard this is also hard on the slide bolts. The fix is to re-drill the holes 1 size larger with a larger bolt.Hole is nice and round. Thanks for the suggestion.

The age is about the norm for shearing bolts. First thing you do is make sure the to redrill the drive shaft tube. I KNOW you stated it is round, but after 6 years, it HAS to have enlarged some. You need to make sure any hardened bolt, that NO threads are in any part of the torque area. The smooth shaft needs to be all the way thru and slightly extend past the exit square shaft tube. The weakest point is if any threads are still contacting the drilled holes in the driveshaft tube. ANY slop in the drift shaft holes will hasten shearing. That is why I advise to cut off the existing tube end and drill a slightly smaller hole and slowly ream the hole out to get a very tight fit when the bolt goes thru. Doug

Same slide shear bolt broke again! Questions for you.

hogbob
Explorer
May 15, 2013
Make sure the motor is bolted up tight.If the motor is lose it will cause a bind. The motor might need new longer bolts. Kenny
Thunder_Mountai
Explorer II
May 15, 2013
wa8yxm wrote:
Twice in six years is nothing to worry about, I've done them twice in six DAYS.

When replacing the bolt make sure of two things (well 3)

One: The condition of the holes.. Need to be round, not oval.

Two: The bolt GRADE 8 please

Three THe bolt Needs to be long enough that the SMOOTH (Shank) NON threaded portion of the bolt goes all the way through the shaft.. Use washers to build up the siaft size on the nut side so the nut snugs down with the proper torque.

DO NOT have any portion of the threads in the shaft or you will be replacing it again,,, SOON.

Thanks for the input. Since I'm not taking the MH out until July, I can take my time on this repair.
MEXICOWANDERER
Explorer
May 15, 2013
As a hint HolloCrome Allen-head bolts are better grade fasteners as are genuine "CAT" (caterpillar) grade 8 bolts. On critical shear applications I had to use longer bolts, then cut custom length threads with a die. Use hardened flat washers and a correspondingly strong STOVER LOCK NUT and a torque wrench to verify clamp pressure.
wa8yxm
Explorer III
May 15, 2013
Twice in six years is nothing to worry about, I've done them twice in six DAYS.

When replacing the bolt make sure of two things (well 3)

One: The condition of the holes.. Need to be round, not oval.

Two: The bolt GRADE 8 please

Three THe bolt Needs to be long enough that the SMOOTH (Shank) NON threaded portion of the bolt goes all the way through the shaft.. Use washers to build up the siaft size on the nut side so the nut snugs down with the proper torque.

DO NOT have any portion of the threads in the shaft or you will be replacing it again,,, SOON.
dougrainer
Nomad
May 15, 2013
aruba5er wrote:
The SHEAR pins in mine are definitly ShEAR pins or bolts> They have groves machined into them. One right at the head and another grove around an inch from there. Right where the square tube would be.

Well, I WORK on RV's and have for 34 years and NEVER have I seen Bolts with any grooves in them and they are NOT Shear bolt/pins. They are grade 5 bolts and have the long smooth shaft to prevent any part of the threads from engaging the square driveshaft. It would be a pain to try and install what you claim are shear pin bolts and then ALIGN those grooves to evenly match the driveshaft metal edges. Me thinks what YOU see are grooves are the marks that have already started the shear off process. They were not there originally, but have appeared from the constant shear action of the drive shaft. I went to parts today and pulled Tiffin driveshaft bolts and Powergear driveshaft bolts and NONE had any such grooves. What other slide parts are protected from a shear off bolt??? Doug
aruba5er
Explorer
May 15, 2013
The SHEAR pins in mine are definitly ShEAR pins or bolts> They have groves machined into them. One right at the head and another grove around an inch from there. Right where the square tube would be.
dougrainer
Nomad
May 15, 2013
Peg Leg wrote:
Do not replace it with a harder bolt. It's a shear pin, meant to break so it protects more expensive hardware.

WHAT more expensive hardware?????? It is NOT meant to be a "shear" pin. It is a BOLT that connects the driveshaft assbly to the motor assbly. The Motor assbly cannot create more torque to "break" any other part in the slide system. The slide just will NOT move if something stops the system from moving. The driveshaft bolts are just the weakest point in the slide mechanism. That is why they shear off. THAT is the word. They shear OFF, not because they are designed to do that, that is the term when they break off. Doug
bucky
Explorer II
May 15, 2013
He just did. Depends on how you look at it. Twice in 6 years isn't a big deal. Carry a spare and roll on. What do you think he should do? :)
nbounder
Explorer
May 15, 2013
OK Pegleg - you said what NOT to do . . . .now, tell us what SHOULD he do?
Peg_Leg
Explorer
May 15, 2013
Do not replace it with a harder bolt. It's a shear pin, meant to break so it protects more expensive hardware.