I understand that hensley hitch requires exactly 45ftlb on the U-bolts. Is this as an absolute? How realistic is it to have just that torque level on all U-bolts all the time? Does anyone have "real world " experience with this requirement?
I agree with the last person. It is probably more important to have them nearly the same--torque-wise. Realistically, you cannot read a torque wrench exactly and they all have some margin of error. So set your wrench at 45 and wait for the click as you tighten. I do , however, check the torque at least every 1000 miles--but for the record after the first time or two they have stayed close to the 45 lb. setting.
As for the Hensley , do, however, grease the zerks and oil the jack springs frequently. I do it more often that the 1000 mile suggested --perhaps about every 700 or 800 miles.
Having traveled about 20,000 miles with the H/A hitch on the 34' Limited TT behind a 2500 Suburban and keeping the hitch lubed and torqued, I am very satisfied with the operation of the hitch.
I did have one mishap with it though, while returning from FL 4/'02, I had to jump on the brakes with both feet to avoid hitting some slower vehicles in front of me. (OK, I acknowledge that I wasn't paying attention closely!). The Tekonsha brake controller didn't react soon enough for the TT, although the TTs brakes did lock up, there was about 9K+LBS not stopping soon enough for the H/A hitch.
The U bolts on the curb side allowed the hitch to slide back on the tt hitch thus shearing off the shear bolts on the curb side only.
I called H/A about this and there response was that the shear bolts did what they were supposed to, but he thought that possibly they weren't tight enough.
I replaced them but was unsuccessful at retorquing them to 45 ft.lbs.; the threads stripped out of the hitch. Even on the side that wasn't effected, they stripped out. I feel confident that the Craftsman torque wrench is accurate and I know how they work, etc.
I was told by the factory to tighten the u-bolts VERY tight but not tight enough to distort the thick steel plate between the nuts. This is beyond the 45 LBS torque and WAY beyond they tightness that they were. I tested the torque on these and they are beyond 100 ft. lbs.
I now feel confident that the hitch will stay where it is supposed to be. I do think that if I ever have to stop that fast again, I will probably bend something rather than shear the bolts that won't tighten to 45 ft.lbs.
I have taken the H/A a part each year I have owned it and am very satisfied with the performance of all the components except for the shear bolts. (In my opinion their self threading shear bolts aren't going into holes small enough for them to hold solidly).
LTD,
You mention you have a Limited. You didn't put the U-bolts over Airstream's stainless A frame covers did you? If so, it's probably impossible for the U-bolts to get sufficient grip on the frame not to slide and the shear bolts will have to take all the load. I removed and stored the A frame covers when I installed the hitch.
FWIW, that's why I like the Jordan Ultima controller... an inertia controller is always following what the rig is doing.
TCP,
Use a torque wrench, crank the nuts down finger tight until the plate is level and then tighten them each to about 20 ft-lbs, then go for 45.
You're correct on greasing the H/A prior to 1000 miles. Per Jarrod @ H/A they now recommend greasing every 500 miles instead of 1000 because people were not greasing at the correct intervals and this was leading to permature part failure.
John
Rereading these threads, I am puzzled. I think there is confusion between the shear bolts and the u-bolts. The shear bolts are the self threading bolts that hold the hitch in a certain location. You can easily overtighten these and strip out the threads. These are the bolts that screw horizontally into the A-frame.
The u-bolts clamp the Hensley to the frame, and I guess you could strip the u-bolt threads, but I doubt this would happen at anything close to 45 lbs.
Thanks to everyone for the input.
While installing my new H/A, I managed to break a U-bolt. (They really fly when they snap. Lesson #1: Always wear safety glasses. Half the U-bolt hit and cut my nose but missed my eyes, Thank God!!!) I would say I suppassed 45ftlbs by a fair bit. I ordered a new U-bolt and installed this one VERY Carefully. Set my torque wrench to 25 ftlb then 40ftlb and finally 45ftlb and no broken U-bolts. I will check the torque on the U-bolts again after a couple of test drives this weekend.
Good luck to all and thank you.
[quote]The first days are hardest days, so don't worry anymore..... " Uncle John's Band" by The Grateful Dead
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The bracket that uses the U bolts to mount on the tongue A frame has two purposes. It's a mount for the screw jacks that tighten the spring bars, and it's what the strut bars attach to in order to keep the hitch head perpendicular to the longitudinal axis of the trailer.
Go here and get yourself a Yahoo Groups account if you don't have one already. Then go here to join the Airstream List. In the Files area, I have a write-up on the Hensley and Pullrite hitches here.
kinda understand how it works now. sounds like there is a semi flexible coupling that is in the shape of a trapiziod.(sp?)
looks like a lot of stuff to fix and adjust. (kinda like my old harley!!)
with my current set up i don't need to use any bars since my truck has hd springs. unless i toss the bike in the back. then i like to tighten the load bars up a couple of links to make everything level and get some weight on the steering axle.
for sway control i just have a reese friction bar
everything works well, can't really see what advantage the hensley offers.
Have you weighed each truck axle with and without the trailer?
You might be surprised how much weight is coming off the front axle without using your spring bars... and that's going onto the rear axle in addition to the tongue weight.
Friction sway controls do help reduce sway while the vehicle is in a straight line. The problem is that they oppose the truck turning the trailer as much as they do the trailer turning the truck (especially on tight corners and when backing), and they resist the trailer getting back in a straight line as much as they resist it swaying out. In the rain, when sway control might be most useful, they lose their friction, and you lose sway control.
The Hensley gets rid of all these problems... there's no opposition to the truck turning the trailer, but there's almost infinite resistance to the trailer turning the truck. And the rain doesn't affect it.
There's really nothing complex about it. Most Hensley owners install it themselves and the company encourages that. Hooking up involves backing the drawbar into the hitch, fastening and pinning the overcenter latches, and cranking the screw jacks to tighten the spring bars (like hooking the proper link of a chain on a traditional hitch). Maintenance involves a grease gun on a coupla zerk fittings every 1,000 miles, but you grease spring bars on traditional hitches also.
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