Equalizer Bars, are they correct for my new tow vehicle?

[rperrym]

I have been using 1000 lb bars that came with our hitch when we bought our new 25 ft. Eddie Bauer. We have been towing with a Yukon Hybrid, which has done a good job with it on level highways. It does struggle on grades and will certainly struggle on passes out west. We have ordered a GMC 3/4 ton with a Duramax diesel. We would have rather have had a 1/2 ton, but to get the diesel we wanted we had to upgrade to a 3/4 ton.
Now for the question, do I need to purchase lower capacity bars before I tow my Airstream with the new truck? I have read so many threads about damage to the trailer with heavier tow vehicles and using stiffer bars. Can anyone advise me about this?
Thanks,
Rick

[dznf0g]

IMO, yes. Be prepared....other will disagree. Problem is, EQ does not sell interchangeable bars. IIRC, you can get 6000# head with 600# bars and 10,000# head with 1000# bars. I don't think a 600# head is enough for your AS.

This leaves you with a new hitch setup in your future...again....IMHO.

[ROBERT CROSS]

What works for us....

2500 06 Burb, HaHa, 1000lb bars.

Best case, try the 1000, set the rig up on the scales, do the "jump" test on the tongue and tow.
If you can get the WD set properly with enough "give" in the rear suspension go for it.

Bob

[Inland RV Center, In]

Originally Posted by rperrym

I have been using 1000 lb bars that came with our hitch when we bought our new 25 ft. Eddie Bauer. We have been towing with a Yukon Hybrid, which has done a good job with it on level highways. It does struggle on grades and will certainly struggle on passes out west. We have ordered a GMC 3/4 ton with a Duramax diesel. We would have rather have had a 1/2 ton, but to get the diesel we wanted we had to upgrade to a 3/4 ton.
Now for the question, do I need to purchase lower capacity bars before I tow my Airstream with the new truck? I have read so many threads about damage to the trailer with heavier tow vehicles and using stiffer bars. Can anyone advise me about this?
Thanks,
Rick

Initially use what you have.

Do the "jump" test.

Then make your decision.

My experience says the jump test will fail.

Andy

[JStanley]

When I upgraded from a ½ ton Chevy to a 2500 Chevy, I was told my original 1,000 lb. spring bars are too strong, and I should get 800 or 600 lb. bars. The bars don’t bend or spring as they should, and maybe it caused some internal rivets to pop. I have a 25 ft., 2006 Safari, and I’m not sure if 1,000 lb. bars were the true cause of popped rivets.

I asked Andy Thompson of Can-Am RV, and he said I would be alright trying lower-rated bars. I called Easy-Lift, and the tech said it would cost just a few dollars more to get a new assembly. He also suggested I try using one less chain link and measure any differences in heights on the tow vehicle.

So next time I hitch-up I’ll try it with one less chain link, even though it is hard lifting the lever. I was told it is possible to break that steel lifting lever by over stressing it while hitching-up. Is that true? If one less chain link doesn’t appear to help, I might just buy a new WD assembly.

[perryg114]

Ok Andy I'll bite what is the jump test. I am assuming you jump on the trailer tongue and look for what?

Perry

Originally Posted by Inland RV Center, In

Initially use what you have.

Do the "jump" test.

Then make your decision.

My experience says the jump test will fail.

Andy

[dznf0g]

I could never get any more than minimal movement with my EQ/100# with the jump test. Virtually none....and I have 850# TW.

[JimGolden]

All you have to do is get your 1000lb bars ground down in the middle to the same cross section as the 600lb bars, and then you will have 600lb bars that work with your 10,000lb capacity head. Others on here have done it.

Just measure a set of 600lb bars for their height and width. Take your 1000lb bars to a machine shop and have them grind the middle down to the same dimension. Taper it back to full size over about 8" either direction.

Problem solved, and it won't cost that much to get them ground. You could do it yourself if you have disk grinder. The key is to get it a smooth hour glass shape with no sharp transitions.

Best of luck,

[ROBERT CROSS]

"So next time I hitch-up I’ll try it with one less chain link, even though it is hard lifting the lever. I was told it is possible to break that steel lifting lever by over stressing it while hitching-up. Is that true? If one less chain link doesn’t appear to help, I might just buy a new WD assembly."

JS,

If you use the tongue jack to raise the front of the trailer, it will be much easier to lock the bars in place.

Bob

[dznf0g]

Who has done it, Jim, and has miles afterword? I have seen it suggested several times, but haven't seen a post of someone actually doing it. I was tempted, until I found my used Hensley.

[mefly2]

Originally Posted by JimGolden

All you have to do is get your 1000lb bars ground down in the middle to the same cross section as the 600lb bars, and then you will have 600lb bars that work with your 10,000lb capacity head. Others on here have done it.

That's me ... I went into uncharted waters and I detailed this for our EQ hitch some time ago when we felt the need for a 3/4 Ton as you have.. Check for my earlier post on just how to do this process and PM if you need further help hints.
It is not as easy as implied above, smooth transitions are essential ... but can be done at home with a good angle grinder; a machine shop project cost will likely take the bite out of the cost of a new hitch at $75+ / hour ...

[aftermath]

Originally Posted by JStanley

...I asked Andy Thompson of Can-Am RV, and he said I would be alright trying lower-rated bars. I called Easy-Lift, and the tech said it would cost just a few dollars more to get a new assembly. He also suggested I try using one less chain link and measure any differences in heights on the tow vehicle.

So next time I hitch-up I’ll try it with one less chain link, even though it is hard lifting the lever...

I am pulling my 2006 25 FB with just a half ton Tundra. When I got the trailer it came with the Equalizer hitch with the 1000 lb bars. I adjusted the head/setup so that everything was level and it worked out for my setup in a way that the hitch was not overly tight or stiff, if that makes any sense. After nearly 10K miles it works fine and I have no popped rivets.

An Equalizer hitch does not have a chain as mentioned above. You can lessen the tension though by adjusting the head and the L brackets and get a similar result to changing which link on the chain you are using.

Make sure you are talking about Equalizer hitches and not "an equalizing hitch".

[Drathaar]

I just had this conversation with my dealer. Their practice is to use a 1000 lb hitch/bars on 25 and larger trailers. My only complaint is about the saddle brackets moving on the frame. The suggested remedy was to disconnect the bars before backing with sharp turns. Next trip is in a few weeks, so we'll see.

[Inland RV Center, In]

Originally Posted by perryg114

Ok Andy I'll bite what is the jump test. I am assuming you jump on the trailer tongue and look for what?

Perry

Perry.

The "jump" test is done when the trailer and tow vehicle are hooked up, ready for the road.

Get up on the coupler and "jump" up and down.

That will tell you the relative stiffness or softness of the rigging.

To stiff is damaging to the trailer.

Andy

[Inland RV Center, In]

Originally Posted by JimGolden

All you have to do is get your 1000lb bars ground down in the middle to the same cross section as the 600lb bars, and then you will have 600lb bars that work with your 10,000lb capacity head. Others on here have done it.

Just measure a set of 600lb bars for their height and width. Take your 1000lb bars to a machine shop and have them grind the middle down to the same dimension. Taper it back to full size over about 8" either direction.

Problem solved, and it won't cost that much to get them ground. You could do it yourself if you have disk grinder. The key is to get it a smooth hour glass shape with no sharp transitions.

Best of luck,

Jim.

I disagree.

Cutting the entire bar down, would be OK.

Cutting a section out of it, creates a huge weak spot, that will snap when enough stress is applied.

As an example, take a 2 x 4 board, and cut out a section in the middle, and then stress it.

Guess where it will break.

Cutting that board so that it's a 2 x 3 as an example, while making the board weaker, it will not have a weak spot, assuming no knots in it.

Andy

Andy

[switz]

That jump test would produce different results if the jumper weighed 110 pounds or crossed the scales at 275 pounds....

[mefly2]

Originally Posted by Inland RV Center, In

Jim.

I disagree.

Cutting the entire bar down, would be OK.

Cutting a section out of it, creates a huge weak spot, that will snap when enough stress is applied.

As an example, take a 2 x 4 board, and cut out a section in the middle, and then stress it.

Guess where it will break.

Cutting that board so that it's a 2 x 3 as an example, while making the board weaker, it will not have a weak spot, assuming no knots in it.

Andy

Andy

Respectfully disagree ... not an accurate analogy - boards do not flex as do most metals ... too many years since my engineering classes, but I am sure others here are more current on the technical aspects.

What I do recall is that the transitions from the full size dimension of the load bar to the lesser dimension must be a gradual transition or the base structure of the metal will be impacted upon flexing. The "bar reduction" procedure has worked quite well for us. Full size is needed on the bar end to mate with the head unit.

The key point here is to not exceed the limits of the bar and induce stress in the middle of it ... those archers among us will understand the basics of the reduction as it has been done for centuries on bows ... wood, metal, and composite.

[JimGolden]

Hey Andy,

I agree with you if you were to just make it a notch or a rough blockout. It would need to be blended in smoothly over a fair distance to not get a stress riser.

It is crummy that EQ makes different attachment types for the different capacity bars. They should do one hitch head swivel design that all bars fit.

I wouldn't grind both dimensions of the bar, personally. I'd only modify the height. I would get hold of a 600lb bar and mic it's width and depth. I don't know what they are, but for the sake of argument, just assume the 600lb bars are 1" tall and .75" wide. Now assume your 1000lb bars are 1.25" tall and .8" wide.

You have to calculate the stiffness, which is very simple. The formula is I=(bh^3)/12 where I is called the Moment of Inertia and relates to bending stiffness. B is the base width, and H is the Height. So for our 600lb bars, we have I = (B * H^3)/12 --> I= 0.75 * 1^3/12 = .0625 in^4.

So now, you simply have to make your 1000lb bars equal that value.
Stock, they are: I = (0.8 * 1.25^3 )/ 12 = .130 in^4. You can see that the stiffness here goes up with the cube of the height, so making the bar a little deeper makes a huge difference in stiffness.

But anyway, what I would do is set my I = to 0.0625in^4, and then keep the width the same on the 1000lb bars, just reduce the height. So if you solve it that way, you have: 0.0625 in^4 = (0.8 * H^3)/12. You solve for H, and you get H=0.98".

So, I would mark my bars about 15" aft of the pivot point, and grind off an equal amount top and bottom. Slightly over 1/8" in this example. I would taper that out over a nice long distance, at least 8" either side.

It's the vertical bending stiffness that you're trying to match up. You could do this with a disk grinder and a belt sander at home easily enough. Just make it smooth.

You could also do like Andy suggested and just grind the whole bar down, though you'd have to leave it thicker at the head stock end where it goes into the hitch head.

You certainly do not want an abrupt transition anywhere, as that would lead to stress risers and you could fail the piece.


It would be easier to just buy another hitch. But if money is tight, this could be done at home.

My buddy has a Bridgeport mill, so I kind of forgot about having to pay a machine shop But yeah, that would alter the equation a lot. But no more material than would probably need to be removed, I'd probably just do it with a grinder, a file, and some emery paper. Don't forget to paint it...

Take care,

[Gene]

Equalizer will tell you that even if you have oversize bars, it doesn't matter—you use only what you need. My brief experience with engineering as a major only lasted a few months, so I don't understand the equations, but 45,000 miles of towing with oversize bars (the dealer selected them before I knew better) and no problems is good enough proof for me.

Gene

[Inland RV Center, In]

Originally Posted by switz

That jump test would produce different results if the jumper weighed 110 pounds or crossed the scales at 275 pounds....

Also depends on how high you jump.

The real purpose is to do something, instead of assuming.

Answers are always better than guesses.

Using the "KISS" strategies most always provides meaningful information.

Andy