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Old 08-11-2012, 09:44 PM   #71
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I don't mind helping, I just don't know what a free body diagram is. Is it anything like the chalk marks they draw around a dead body?
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Old 08-12-2012, 01:47 AM   #72
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Just to be clear...

The pressures placed on the chassis are the same using a drop mount/hitch vs. angled towbar, BUT with the drop hitch - isn't there MUCH more torque placed on the on the receiver's crossbar?

A. Pulling/twisting up during acceleration and when bumping into a errant driveway or incline
B. Pushing/twisting down during braking (hopefully mitigated by brakes on the Toad).

So, is it agreed that because of the dangers of the torque (sheared receiver or broken drop mount/hitch) - it seems that the lesser of 2 evils is to accept the towbar being at an angle?
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Old 08-12-2012, 06:25 AM   #73
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Quote:
Originally Posted by Scarab0088 View Post
Just to be clear...

The pressures placed on the chassis are the same using a drop mount/hitch vs. angled towbar, BUT with the drop hitch - isn't there MUCH more torque placed on the on the receiver's crossbar?

A. Pulling/twisting up during acceleration and when bumping into a errant driveway or incline
B. Pushing/twisting down during braking (hopefully mitigated by brakes on the Toad).

So, is it agreed that because of the dangers of the torque (sheared receiver or broken drop mount/hitch) - it seems that the lesser of 2 evils is to accept the towbar being at an angle?
Guilt on all counts. , but... tpm64 was asking about the breaking difference between the two. With B above, it would enhance breaking by putting more pressure on the rear tires.
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Old 08-12-2012, 12:33 PM   #74
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Scarab0088, That is the point I was trying to get to.

Dunner, Since I was not able to present my argument well, I was asking you to look at the forces on the tow bar and figure it out yourself. I apologize if it came across as augumentative - I was just trying to get folks to think it through.
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Old 08-12-2012, 01:04 PM   #75
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I didn't think it was argumentative at all. And why would I want to figure it out for myself? I thought you were wanting to know it the braking was better or worse with a drop hitch compared to an angled tow bar.

Final answer: Yes, a drop hitch would give you better braking as opposed to an angled tow bar trying to lift the rear of the TV upon braking.

The force is the same but the drop hitch is pushing straight forward as opposed to the tow bar pushing upward.
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Old 08-13-2012, 01:44 AM   #76
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Quote:
Originally Posted by Arch Hoagland View Post
A week or so ago there was a thread about using a drop hitch so the tow bar assembly would be fairly level.

I stated a concern that with the drop hitch your hitch could drag on the ground and apply a force of 10,000 to 15,000lb on the hitch assembly, exceeding the manufacturer's weight limit.

Another forum showed the result of this overload.

RV.Net Open Roads Forum: Partial Hitch Receiver Failure - NEW PHOTO

I tow a Miata and the height difference exceeds the tow bar recommendations, however, I don't want a drop hitch causing this problem.
I'm the O.P. and want to thank all of you who have contributed to this thread.

My point is still the same. I don't care what you do to the receiver assembly, adding a roller assembly, etc.

You are still vastly overloading it when you drag it on the ground, roller wheel or not.

So lowering it will only create more ground strikes.
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Old 08-13-2012, 01:55 AM   #77
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Stay out of it Arch. We're currently engaged in Off Topic jabber.
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Old 08-13-2012, 01:57 AM   #78
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Drop Hitch problem

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Originally Posted by Dwight View Post
My setup required a 8" drop hitch and I got in trouble trying to get into the wrong gas station and my tow bar scraped so hard it cut both safety cables in half without hurting the tow bar.

I found two 6 degree axle shims 4" wide & 6 1/2" long and installed them between my 1995 Ford F53 motor home chassis and the original Bounder hitch receiver and I have a perfect straight line from my hitch receiver to my connection on my 3000# Subaru Forester with a NSA Ready/Brake Elite tow bar with the surge brake system. Works perfect.

I now have a heavy 8" drop receiver to use as a boat anchor.
Dwight
I originally brought up the subject of the receiver hitch mounted at an angle to open up discussion about eliminating the troublesome additional 8" drop hitch receiver.

My F53 has 13' of overhang from the rear axle to the rear bumper and the 8" drop receiver hitch adds another 1'. My 98 Subaru Forester has a low center of gravity and weights 3000# and was a perfect candidate for me to run a trial with the frame mounted angle receiver and no 8" drop receiver.

It has worked beautifully and I have peace of mind like I never had with the drop receiver. I can drive almost anywhere and feel comfortable with my setup in case I encounter a panic stop because it stops just like it did without my tow behind me.

I remember the time a school bus pulling a single axle trailer with a drop receiver tried to pull into a McDonald's and hung up so hard on the drop receiver that the single axle trailer had to be unhooked and a wrecker had to lift the bus to move it and all the while blocking traffic on a main highway.

I'm staying with my frame angled receiver and NSA ReadyBrake Elite Tow bar.

Dwight
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Old 08-13-2012, 05:37 AM   #79
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Hi Dwight, do you have a picture of your set up?
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Old 08-14-2012, 01:24 AM   #80
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A picture will only show the towing system is a straight line from the Subaru connection into the receiver hitch on the motor home.

The pair of 6 degree axle wedges don't show on a picture of the receiver hitch when installed.

Each wedge is 4" wide and 6 1/2" long. 3/4" thick on one end and tapers to 1/16" thick on the other end. I was lucky to find the brass wedges molded with 4 long slotted holes that allowed longer bolts to be used on the thicker end without drilling holes in the wedge and the wedge can't slide out without removing the bolts that hold the hitch receiver to the motor home frame.

I had seen these two old used wedges hanging on the wall of a heavy duty truck axle alignment shop years ago and two years ago they were still hanging there waiting for me.
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Old 08-14-2012, 10:27 AM   #81
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OK Dwight, but Im still unclear what you have. Straight line? Is the connection at MH higher than the connection at the toad? Yet still a straight line? Or are the connections equal heights off the ground and in a straight line.
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Old 08-14-2012, 10:32 AM   #82
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I take it the receiver(the part a/the hitch plugs into) is at the same angle as the tow bar, but higher.
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Old 08-14-2012, 05:16 PM   #83
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The tow bar attachment pins on my Subaru are 13" above the ground and the center of the hitch receiver on my Ford Bounder is approximately 22" above the ground.

The 3/4" thick end if the 6 degree shim is placed between the hitch receiver and the Ford frame with the 3/4" end toward the rear of the M/H and the 1/16" end to the front.
I used the same bolt holes with longer high strength bolts on the thick end and reused the original bolts on the thin end. The slots in the shims just happened to line up with the original bolt holes.

I have located shims available on line for about $12 each in sizes from 1 to 4 degrees in the 4" width X 6 1/2" length. 5 & 6 degree shims may be harder to to locate.
Shims this size are used in heavy duty industry to change front axle tilt for steering corrections and rear axle for drive shaft angles.

I have pictures but have been unable to post them.
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Old 08-14-2012, 06:42 PM   #84
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I know I don't count and I think I know what you are talking about, but I need pictures to be sure.
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