Flex Air Pin Box Installation

[Ray Keymaster Vancouver Island]

See Full Blog Post – http://www.loveyourrv.com/installing-the-flex-air-pin-box-on-our-fifth-wheel-trailer/

I installed a new Flex Air Pin Box by Lippert Components onto my Keystone Cougar fifth wheel trailer.

The new pin box comes with several features to smooth out the fifth wheel trailer towing experience.

1) Built-in adjustable air bag
2) Oil filled shock absorber
3)Thick rubber buffer
4)Pivoting kingpin head

Installation was fairly straight forward other than dealing with the 225-pound weight of the pin box. I utilized a hydraulic lift cart to do the job. Also required was a torque wrench to tighten the bolts up to 160 lbs. The bolts used are 5/8ths with 15/16 inch heads and nuts.

Stay tuned for a future video with my full review of the Flex Air. We are headed out for some extensive travel over a variety of terrain in the next few weeks. I’ll post the review after.

RVHH Chief Cook and Bottle Washer - LoveYourRV.com

[Eddie & Aileen Moderator Oshoto,Wyoming USA]

Nice Ray!!!

Now you will be hauling on a cloud!

Happy (Soft) Trails…Pal!!!

[LolaandRush Participant Rocky Mount,N.C.]

Looks like a rather easy install with the lift. Eddie mentioned we needed to look into those account of as you explained the bumps and snatch points along the hiway. Thanks for the info.

We are retired as of July 1st. 2015.

[Dan Huhn Participant Shoreline Wa.]

nice install Ray, i see that pin box on alot of  5th wheels. I look forward to hearing how you like it .

[Ray Keymaster Vancouver Island]

Thanks guys, should be a sweet ride now!

With some advice in the YouTube comments, it looks like I may have over torqued the bolts also tightened them the wrong way.

I had went with 160 lbs found in a Lippert install PDF but the bolts are only Grade 5 medium steel coarse thread by the looks of them. Most bolt torque spec tables found online say either 150 or 154 as max torque. for those bolts.

Also many of them I had the torque wrench on the bolt head and it should be done on the nut side due to differences in surface areas between the flat washer and the lock washer.

I think I’m going to upgrade the bolts to Grade 8 with max torque over 200 and reverse them so the nuts are facing out and I can then torque them on the nut. It’s too hard to get at some of them inside the pin box.

I’m sure shearing off the bolts with my light weight fiver adn with just a little bit over over torquing is pretty slim but bolts are cheap. So may as well throw on some new ones.

Cheers!

 

 

RVHH Chief Cook and Bottle Washer - LoveYourRV.com

[Ray Keymaster Vancouver Island]

*UPDATE* – I decide to replace the original Grade 5 bolts with Grade 8 bolts. I learned that Grade 5 bolt max torque is 150lbs where the same size bolt Grade 8 is over 200 lbs. Also, I’ve reversed them with the nuts on the outside. I was advised that they should be torqued on the nut rather than the bolt head. It was too difficult to fit the torque wrench inside the pin box to get at the front bolts.

RVHH Chief Cook and Bottle Washer - LoveYourRV.com

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