Andersen AUH - Threads Ready to Strip in Square Coupler Tube

[roegs01]

Agreed. Assuming based on torque listed the bolt is 1/2" course thread. When anti-seize is used it will lower the fiction coefficient. You are not close to bolt yield so that's not a concern. The aluminum threads have deformed under clamp load. Worn tap during manufacturing or a torque wrench out of calibration are potential causes. Looks like there is the required bolt thread engagement to hold the clamp joint based on bolt size from the pictures. I lean to the possibility the part was defective from Anderson. Hope they honor your claim.

Dutchman2

Also, if the bolt is removed frequently an anti-seize lubricant should be considered because the nut is aluminum so wear becomes more of a concern. If the threads have issues down the road run a tap to clean some and then lubricate on occasion.

After looking closer at the female thread, it appears that there is some thread yielding going on. The tread is raised above the plate surface. A counter sink should have been drilled before tapping. This material could break off and get pulled farther in the part. Also, the aluminum yield strength is very likely somewhat less than even a grade 2 bolt so the specified torque should be less than a steel bolt in a steel nut.

Due to the mentioned yielding, the applied load during use maybe too high for the thread size.

Thanks for looking closer at the threads. Andersen did honor my claim and sent a new aluminum insert and replacement bolt. After thinking this through a little more I decided to use some thread lubricant. I have some nickel based anti-seize. Can I use that?

 

[Hoopy Frood]

Thanks for looking closer at the threads. Andersen did honor my claim and sent a new aluminum insert and replacement bolt. After thinking this through a little more I decided to use some thread lubricant. I have some nickel based anti-seize. Can I use that?

Works for me.

 

[Dutchman2]

Works for me.

Ditto -

Dutchman2

 

[PJOB]

Photos show the main point of what's going on with my AUH. This is the bolt that gets torqued to 60-70 ft pounds. I noticed the last few times I used the hitch that the bolt was turning harder than normal as I torqued it up. After a closer look the threads are very worn and some of the aluminum thread material has bonded to the bolt. For those that use the AUH, have any of you experienced this before? I'll call Andersen Tech Support tomorrow and see what they have to say. I'm thinking that there is a new coupler tube in my future.


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REMOVE AND FULLY INSPECT THE SQUARE TUBE COUPLER!

We are seasonal RVers. I have about 25,000 miles on my AUH, hauling a 303. I remove and reinstall the hitch multiple times per year. I faithfully torque the top and side bolts. At around the 15,000 mile mark, I noticed aluminum shavings in the truck bed directly below the side retaining bolts. Upon inspection, I found that the retaining bolts had almost completely worn through the side of the coupler.
Andersen customer service was great! They shipped a replacement coupler and I received it in less than a week.
I now routinely inspect the coupler and rotate it, as the steel bolts continue to 'chew' indents into the side of the aluminum coupler.

 

[Hoopy Frood]

REMOVE AND FULLY INSPECT THE SQUARE TUBE COUPLER!

We are seasonal RVers. I have about 25,000 miles on my AUH, hauling a 303. I remove and reinstall the hitch multiple times per year. I faithfully torque the top and side bolts. At around the 15,000 mile mark, I noticed aluminum shavings in the truck bed directly below the side retaining bolts. Upon inspection, I found that the retaining bolts had almost completely worn through the side of the coupler.
Andersen customer service was great! They shipped a replacement coupler and I received it in less than a week.
I now routinely inspect the coupler and rotate it, as the steel bolts continue to 'chew' indents into the side of the aluminum coupler.

That really doesn't sound like a reliable design. Hopefully Andersen has lots of information about changing out these parts regularly. Wonder why that part isn't steel instead of aluminum?

 

[roegs01]

......Upon inspection, I found that the retaining bolts had almost completely worn through the side of the coupler.....

I've seen wear on mine, but not to that degree. I torque the two front retaining bolts to 40 ft/lbs. I've read about others torquing to a higher value. What torque spec are you using for yours?

 

[SilentService]

I've seen wear on mine, but not to that degree. I torque the two front retaining bolts to 40 ft/lbs. I've read about others torquing to a higher value. What torque spec are you using for yours?

Anderson recommends 60 ft lbs on both top bolt and the two side bolts.

 

[SilentService]

REMOVE AND FULLY INSPECT THE SQUARE TUBE COUPLER!

We are seasonal RVers. I have about 25,000 miles on my AUH, hauling a 303. I remove and reinstall the hitch multiple times per year. I faithfully torque the top and side bolts. At around the 15,000 mile mark, I noticed aluminum shavings in the truck bed directly below the side retaining bolts. Upon inspection, I found that the retaining bolts had almost completely worn through the side of the coupler.
Andersen customer service was great! They shipped a replacement coupler and I received it in less than a week.
I now routinely inspect the coupler and rotate it, as the steel bolts continue to 'chew' indents into the side of the aluminum coupler.

I don't have the amount of mileage on mine like you do. That said, I have never taken mine apart to inspect the inside where the two bolts torque down. I have had mine for 6 years now and have always torqued all the bolts to 60 ft lbs (the two side bolts use to be 40 ft lbs but Anderson changed that a few years back.) I have not seen any metal shavings but will check for signs of wear as soon as I can.

 

[roegs01]

Its interesting that they changed the sidebolt torque. My old manual shows 40 ft lbs but as you mentioned the new manual says 60. Thanks for the info.