Hensley Hitch Shearing Retainer Pins

[Brown Trout]

Friends, I'm the new owner of a 2003 Airstream Classic 31' equipped with a Hensley Arrow Hitch, also mfg in 2003. The previous owner had a recurring problem with the Hensley shearing Retainer Pins that hold the Spring Bars up in the lower unit. Over the course of 5 yrs he sheared Retainer Pins on both Spring Bars, about 10 in total

I've owned the trailer 3 weeks and sheared my first retainer pin last evening during a 10 mi. move from storage to my home. At $16/pin it's something I want to fix.

Hensley company records indicate that the first owner of the Airstream reported no problems with the hitch's Retainer Pins or Spring Bars. So, the guy I bought the trailer from was first to experience the problem. He occasionally bottomed out the hitch on his rural lane and cracked the double-barrel bushing into which the Spring Bars fit. He replaced the bushing. Retainer Pins kept shearing.

This morning Hensley advised me to inspect the groove in each of the two Spring Bars for burrs or obstructions. And, then to be gentle when pushing (rocking) the Spring Bars back into the lower unit bushing. I plan to do that asap.

Has anyone had a similar problem with their Hensley Hitch eating Retainer Pins???

The only other info I can think to pass along is that the Hensley's Spring Bars are the heavy duty type, not the lighter ones. And, the replacement bushing appears to have been installed correctly in the lower unit (otherwise, Retainer Pins would not fit in place).

Thanks!

Myron

[J. Morgan]

Is it possible that the grove on the end of the bars is chewed up and grinding the ends of the pins off in normal use?

Maybe someone once put the wrong pins/retainers in and damaged the bars?

While the pins will be made of good hard steel, so will the spring bars. Abrasion here might eat pins like mad.


Superat stultitia.

[ROBERT CROSS]

In 10yrs never a failure, I do remove the haha every fall for Winter storage so they get inspected regularly.

IMO...the most likely cause, the zerk is installed to deeply, the 'nub' should be the only part projecting past the wall of the bushing and only enough to secure the bar.

A finger in the hole is the best way to make sure that doesn't happen and it's very important to check carefully AFTER the lock nut has been tightened.
Tightening can/will turn the entire fitting.

Bob

[dznf0g]

Yes I have, and I believe I have cured it.
Certainly filing any burrs in the spring bar grooves is needed.
There are (were?) two different bushing assemblies available. One has a chamfer machined in the lower (as installed) lip, running around the circumference of each barrel of the bushing assembly. My understanding is depending on manufacture date and the specific bar procured by Hensley at the time (or bars that may have been swapped out) the chamfered bushing MAY be required.

In my case, I had the non-chamfered bushing and could not easily even get the bar to slide in high enough to get the pin to pop into the grove. Once I got it in, there was a tension between the pin and the area of the bar on the inside of its 90* bend at the very base of the bushing lip. This caused very rapid wear to the pin and pretty rapid failing of the tip. I also believe that this binding of the bar in the bushing allows for extreme point loading of the WD force on the bushing lower lip which caused the breaking of weld between the bushing half and the bar running between them.

I procured a chamfered bushing set and am now on year 5 on the same pin set. And no further bushing breaking.

BTW, I found, through McMaster Carr some similar tips for about $4 each, modified them for grease flow and will reuse the present barrels, when needed. That's in an old thread around here somewhere. I'll see if I can locate it.

I took the old bushing set and ground a chamfer in it with a conical stone and now have the clearance needed. It's my backup in my road repair kit.

[dznf0g]

http://www.airforums.com/forums/f464...ut-146157.html

Post #10 has a link to McMaster Carr page.

[Brown Trout]

First, thanks for passing along the experience/insights.

We have some plans for this Easter weekend but I'll try to make some time asap to I'll remove the spring bars and check for burrs, abrasion or other damage to the groves that might have been caused by using the wrong retainer pins or someone screwing them in too far.

While hitching the Hensley for the first time at the prior owner's property for the drive back home to Indiana, one of the spring bars dropped out of the lower unit to the ground. Old owner walked me through installing a new retainer pin and was very specific not to thread too far into the lower unit. At the time of that install I felt inside the lower unit and confirmed that all I was feeling was the pin and not the threaded bushing. Yesterday it was the other spring bar that dropped out so at least the one that I installed remains in tact.

I'll need to do a more thorough inspection of the double-barrel bushing in the lower unit to see what I've got. Hensley seems to keep pretty good records of parts shipped so maybe they can tell me whether the right bushing was shipped for my unit. That's maybe too optimistic but hope springs eternal.

Again, thanks!

[Tom_T]

I've had no such problems with our Hensley Cub ("Arrow Jr.") on our relatively light 1960 Avion T20 since we got it in 2013.

The PO with the rural raods which started the problem may have damaged something with the alignment &/or fitment of the parts, which is causing both the falling out of the bars you've experienced & the shearing of pins which you & the other PO(s) have experienced.

The above, plus the age of the Arrow as 2003 & the fact that it sounds like you are the 3rd owner or more & no longer under the lifetime warranty - you may want to send the unit up too Hensley for inspection, reconditioning & adding the lifetime warranty to you (IIRC it's about $500 to add it).

They're not too far from you in IN, so the shipping will be relatively short & cheap with hopefully a quick turnaround time (shipping relative to me in SoCal). You may even be able to drive the unit up to them in MI & bring it back, if they can do such a quick turnaround while you wait. Call Terry Powell at Hensley to get the particulars & timing.

I don't know if you can do anything before your Easter trip other than carry several extra pins/etc. If it were me, then I'd be concerned about a trip of any distance with a known faulty hitch.

Good Luck & Safe Travels,
Tom
///////

[Tom_T]

Rich,

While your mods in the quote below show engineering smarts & good machining capabilites....

The concern I would have with your suggested modifications which you've done to your HA, is that they could negate the lifetime warranty, or make it impossible to get a new owner warranty/transfer, or more costly to replace the parts in order to get it.

So I would therefore instead recco owners with a warranty or wanting to get one to not do such mods, but get Hensley to fix the unit under their warranty.

It's just like messing with your car/truck while under warranty, where the mfgrs. specifically state that owner mods can negate their factory &/or CPO warranties.

Best!
Tom
///////

Originally Posted by dznf0g

Yes I have, and I believe I have cured it.
Certainly filing any burrs in the spring bar grooves is needed.
There are (were?) two different bushing assemblies available. One has a chamfer machined in the lower (as installed) lip, running around the circumference of each barrel of the bushing assembly. My understanding is depending on manufacture date and the specific bar procured by Hensley at the time (or bars that may have been swapped out) the chamfered bushing MAY be required.

In my case, I had the non-chamfered bushing and could not easily even get the bar to slide in high enough to get the pin to pop into the grove. Once I got it in, there was a tension between the pin and the area of the bar on the inside of its 90* bend at the very base of the bushing lip. This caused very rapid wear to the pin and pretty rapid failing of the tip. I also believe that this binding of the bar in the bushing allows for extreme point loading of the WD force on the bushing lower lip which caused the breaking of weld between the bushing half and the bar running between them.

I procured a chamfered bushing set and am now on year 5 on the same pin set. And no further bushing breaking.

BTW, I found, through McMaster Carr some similar tips for about $4 each, modified them for grease flow and will reuse the present barrels, when needed. That's in an old thread around here somewhere. I'll see if I can locate it.

I took the old bushing set and ground a chamfer in it with a conical stone and now have the clearance needed. It's my backup in my road repair kit.

Attachment 259290

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[dznf0g]

Originally Posted by Tom_T

Rich,

While your mods in the quote below show engineering smarts & good machining capabilites....

The concern I would have with your suggested modifications which you've done to your HA, is that they could negate the lifetime warranty, or make it impossible to get a new owner warranty/transfer, or more costly to replace the parts in order to get it.

So I would therefore instead recco owners with a warranty or wanting to get one to not do such mods, but get Hensley to fix the unit under their warranty.

It's just like messing with your car/truck while under warranty, where the mfgrs. specifically state that owner mods can negate their factory &/or CPO warranties.

Best!
Tom
///////

That's possible Tom, but in my case it's a non-issue. I bought used and the serial number sticker was long gone (why it's a sticker and not a stamping amazes me). I called to purchase a warranty transfer and they said no way...not without a serial number. At that point I suspected why it's a sticker!

But that's OK, I got it for $800 from an AS dealer who had it on a traded in AS and it was laying in his shop for years..He was glad to be rid of it. It wasn't used much at all, but had sun baked badly.

[guskmg]

dznf0g, Post #4, Ditto. I purchase a 1,000# socket for my 1,400# bars, die ground the holes so the bars would fit good. Meaning the long end of the bar would only move up and down 1/2 ". After few years and a trip to Alaska and back I had a bearing cap fall off. Hensley said send back the hitch assembly. They sent me back a new hitch under their lifetime warranty, no questions, except to say they didn't design the hitch for north Canadian and Alaskan roads. The best way to set the depth of the zerk locking pin is to put the zerk barrel in the socket far enough to hold the bar in. Then, with a 3/8" nut driver, tighten the zerk barrel in until the long end of the bar starts to move up. That is caused by the barrel pushing in on the spring bar. You can move the long end of the bar up and down with the nut driver to get the feel of the barrel just touching the bar. Stop, this is the correct amount. Now, lock down the locking nut, noticing if the barrel moves out slightly due to tolerances. If so, you must add that amount of thread turn to the initial barrel adjustment. Sometime it takes 2 or3 tries to keep the pin in deep enough to prevent fall out. Then, if it does, as the Hensley Instructions say, "turn it in another 1/2 turn". When going over ups and downs in the road the load on the spring bars keeps them mostly forward in the sockets. However, over time things wear and seat causing the need of more adjustment. If you are like me, I don't adjust the zerk barrels until a spring bar falls out while unhitching. Then, the pins are worn and need replacing. If I was more conscientious, and adjusted more frequently, I would save a lot of zerk money. Like over greasing, you probably can not over adjust.
guskmg