Tow bar angle

[UFO]

Originally Posted by Gasoline Fumes

It's pretty common here to tow a car like this with an RV. It still amazes me that the towed car does steer itself.

The reason the towed vehicle steers behind the tow is the front alignment caster angle, it gives stability at speed. All steered vehicles have this, even bicycles.

[UFO]

Originally Posted by EcoCivic

Thanks, that's pretty much what I was thinking lol. It did seem to help a little to raise it up a little, so maybe raising it up until its level would help a lot

Have you checked the alignment on the towed vehicle? I flat tow my old Datsun at highway speeds with no issue, and the tow bar is not perfectly flat.

Also check the condition of the ball joints and tie rods. Any alignment issues will cause problems with stability when towed. The fact that you removed the CV joints may create issues with the front wheel bearings, make sure they are tight - I know Volkswagens need proper axle nut torque for wheel bearing stability.

[EcoCivic]

Originally Posted by iikhod

Wow, you learn something new everyday.
One would think that the towed vehicle would be all over the place when not being pulled by the tow car.

Do you guys have these? Every now and then i see something towed with this kind of setup. In here that is called a dolly.

I thought about renting one, so I called U Haul to see how much they cost to rent. They wouldn't rent me one and they weigh 750 lbs, so I decided it would probably be better to flat tow it anyways to save the weight.

[Xist]

We had tow bars in the Army. We would see Infantrymen running around carrying them (three Soldiers per tow bar). When I, a fueler, ran out of fuel in Afghanistan (It wasn't my fault!), we didn't have any tow bars. They decided to save space and weight in our gun trucks by providing telescoping tow bars, which immediately broke, so we dropped my trailer, another truck picked it up, and they used a short tow cable to tow my truck.

Apparently nobody told them that you are supposed to use your brakes to slow down the tow vehicle. Allegedly they repeatedly bounced off the back.

I was quite blessed that nothing happened to me in Afghanistan.

[EcoCivic]

Originally Posted by UFO

Have you checked the alignment on the towed vehicle? I flat tow my old Datsun at highway speeds with no issue, and the tow bar is not perfectly flat.

Also check the condition of the ball joints and tie rods. Any alignment issues will cause problems with stability when towed. The fact that you removed the CV joints may create issues with the front wheel bearings, make sure they are tight - I know Volkswagens need proper axle nut torque for wheel bearing stability.

Thank you for your help. I have not checked the alignment, but I don't remember it pulling while I was driving it. It's been years since that car has been driven though, so I may not be remembering correctly.

Was your tow bar pointing down as much as mine is? There's a big difference between "not perfectly level" and off by like 1 foot. LOL

Also, to be clear, I did NOT leave the axles completely out. What I did is I took apart 2 old axles I had laying around and took the ends off. I then took the axles out of the towed car and stuck those ends into the wheel hubs of the towed car and torqued them down, that way the wheel hubs are still being held together as they normally would be, just without being connected to the transmission. Hopefully that makes sense

[euromodder]

Originally Posted by iikhod

You guys seriously do this without someone sitting in the towed vehicle? Have to say that's not a risk worth taking.

I have never seen someone do this, so does the towed vehicle actually "follow your turns"? Or is there somekind of link to the steering parts?

Very common in the US

In Europe, only in the UK

Isn't even legal in many EU countries
Towing a functional car is not legal in Belgium, and it needs a driver ...

[euromodder]

Originally Posted by me and my metro

You want the tow bar as level as you can get. You are double loading your brakes towing a similar sized car. .

If the tow bar angles down, it'll push down the tow hook under braking, which then lifts the front, reducing braking ability ...

[EcoCivic]

Originally Posted by euromodder

If the tow bar angles down, it'll push down the tow hook under braking, which then lifts the front, reducing braking ability ...

That's pretty much what I was thinking, thank you. Like I said, there was one time I tried to stop and my front tires locked up and skidded without pressing the brake pedal that hard. I was braking with moderate pressure going about 10 MPH and the front tires suddenly locked up with no warning. I could not tell if the front of my car was lifting up or not, but for the brakes to lock up that easily I'm thinking it must have been. The brakes felt like they were somewhat adequate, but I didn't have traction to stop.

Do you know what effects the tow bar pointing down would have on stability? The towed car seemed to be going straight, but it was pushing my car all over the road. I was constantly having to make corrections to keep it in my lane and I am wondering if the tow bar pointing down could have had anything to do with that.

[euromodder]

Originally Posted by EcoCivic

Do you know what effects the tow bar pointing down would have on stability? The towed car seemed to be going straight, but it was pushing my car all over the road. I was constantly having to make corrections to keep it in my lane and I am wondering if the tow bar pointing down could have had anything to do with that.

It tries to lift the rear while pulling.
Thus making your tow car feel skittish, as if the rear wheels weren't on it ... sound familiar ?


Do you remember vectors from math lessons ?
No problem if you don't, but unless the towbar is level, whatever force happens to go through it will also result in an extra vertical force on your tow hook


Either up or down, depending on
- towbar angle
- what 's happening (you pull, or the towed car pushes you under braking)

[euromodder]

Oh, when the tow bar is not level, you see that F is always greater (longer) than Fx (the actual force required to pull your towed vehicle at that speed)

But your engine will need power to deliver F, increasing fuel consumption beyond than it needs to be to tow the car