Community Forums

terry735001 · 01-06-2015, 03:59 PM

one thing to keep in mind is give the towd time to steer

as you said you have alot of RV behind the back tire and so it can swing fast in a turn
you well find if you try to slow this down and give the wheels in the car time to turn/ track it well not be so hard on you .. but in the other hand if you try it to fast the car wants to fight you and turn the other way all together and lock the car tires in the wrong way .. you well find this out one time on sand and have to walk back to the car to fix it

Gordon Dewald · 01-06-2015, 04:22 PM

Percival
It appears your toad is near the towing limit of your RV so its effects on the MH will be higher than if towing a lighter vehicle.

I would expect the cause of your issue is as you suggested; the length of your overhand and the weight of the toad.

When going downhill and turning the toad will attempt to keep going. On of Newtons laws. It will then push on the back of the MH and using the length of the fulcrum will affect the steering by causing over-steer.

When going uphill the toad is continuing to drag back so you should feel some under-steer.

Have you tried to brake the toad manually when going downhill while turning? If you do try this you will have to be prepared for the reaction to go from over steer to under steer. This would be a test and something I would do carefully to see if it is the length of the overhang and toad pushing.

It would seem the easiest thing to do is to slow down prior to entering the curve and then gently accelerate around the curve.

I have a similar type of situation. I pull a trailer with my motorcycle that has electric over hydraulic brakes. The brake light activates a pump on the trailer that puts pressure on the brake pads. There is an adjustment screw that I use to set the braking force which is the same all of the time the brake is on. It works wonderfully on the road. However in parking lots it is impossible to feather the brakes when pulling into a parking space. Just touching the brakes results in the trailer brakes engaging and the trailer trying to pull the bike over to the inside (unless pulling in to the spot in a straight line - does not happen often). I learned to almost stop before making the turn and then using power to gently pull into the parking spot.

McLindy · 01-06-2015, 04:52 PM

you say about 75lbs of bikes on back of toad? how far does the bike rack stick out? had an out of control trailer once, 4 bikes on the back took the bikes off, no more out of control.

Brockx · 01-07-2015, 06:34 AM

Quote:

Originally Posted by Dblegg1

I have a 89 southwind 36' 18,000 lbs and I built a tow bar and brackets for my 95 suburban that is about 6500 - 7000 lbs other then stopping I did not feel it towed it about 500 miles I have now got a braking system for it but have not tow with braking system in it

I would just about guarantee the frame extensions on your coach are inadequate. My 1996 Pace Arrow 33' had 4 foot 4 x 4 angle irons rated at 3500#'s. I shudder to think whats under a 1986 36'

Dblegg1 · 01-08-2015, 09:29 AM

Quote:

Originally Posted by Brockx

I would just about guarantee the frame extensions on your coach are inadequate. My 1996 Pace Arrow 33' had 4 foot 4 x 4 angle irons rated at 3500#'s. I shudder to think whats under a 1986 36'

3x6 channel doubled with a 3x5-1/2 channel

Brockx · 01-08-2015, 10:23 AM

Quote:

Originally Posted by Dblegg1

3x6 channel doubled with a 3x5-1/2 channel

Well, I'm definitely impressed. My 1996 Pace Arrow Vision was Fleetwood's top line gasser at that time and the extensions were pretty meager, Bounders, Southwinds, and std PA's would have shared the same chassis.

mel s · 01-08-2015, 10:40 AM

Quote:

Originally Posted by Percival6

when we entered the first good curve and felt a sudden and unusual amount of over-steer that came on a second after I thought I found the perfect line around the turn. This is especially fun on two-lane mountain roads! I couldn't figure out what was happening!
Tom

Tom
IMO, based on your detailed description of the problem you either "have to much toad" or "not enough coach".
Mel
'96 Safari '07 Saturn ION toad.

wa8yxm · 01-08-2015, 02:51 PM

NEver had that problem I drive a 22,000 pound Class A and used to tow 4,000 pounds of Chevy Lumina APV,, I had the proper hitch adapter so the tow bars were almost level, I had a good braking system (US-Gear Unified Brake Decelerator). Never felt as you describe.

I now tow 2,500 pounds of Dodge neon,, No change other than MPG is down a bit (And yes, I do know why and it makes sense)

Of course when I park the house MPG is up, about double but hey,, I like that (Drive the towed a lot).

This class A is a gasser, which means that towed is a long way behind the drive axel (Which adds to the effect you cite)..

Recommendation:

Trac Bar.. Mine is a front trac bar (And trust me that and a steering stablizer made a BIG difference) but folks tell me a rear Track Bar is better,, I recommend the Ultra Power Trac Bar if it fits your system.

WHY? Motor homes use leaf spring suspension, The springs not only allow movement of the axle up and down relative to the body, but also allow the body to move slightly side to side over the axle.. I recall back around 1960 when they were bragging about Independent Front Suspension on pick up trucks.. (IFS does not need a front track bar). and "Strut" suspension on cars (Likewise)

Trac Bars lock the body dead center over the axle,, stopping this side to side "Wag" 100%.. Try one, (or 2) you will like it.

Betr2Trvl · 01-08-2015, 04:44 PM

[QUOTE=PushedAround;2309552]That is exactly right (old sports car racer here). When you go into a turn off throttle, the back end is light and the toad is pushing you. That is what is giving you the oversteer. When you get on the throttle, the MH squats and loads the rear tires, giving more grip and also pulling the toad in the direction that you are going./QUOTE]

OK, I have yet to get my MH, much less pull my toad.

But, as soon as I read the OP's post, this is exactly what I was thinking. Seems to me, sounds like exaggerated classic Porsche 911 handling believe it or not.

When you are braking, load shifts to the front, the rear with all the weight gets light. When you do this while cornering, you loose rear grip, and all of a sudden you are looking at where you came from instead of where you were going as you spin.

To resolve this phenomenon, you get your braking done in a straight line before the turn in, and before you turn in, you move off the brake and gently add throttle which shifts the weight back to the rear which improves rear grip. Obviously you need to adjust your braking point and corner entry speed to do this which in racer terms, is "slow in, fast out"' since you essentially over slow on entry, and are accelerating in the corner.

Maybe all those track miles will actually pay off in the MH..........

PushedAround · 01-08-2015, 04:54 PM

Quote:

Originally Posted by Betr2Trvl

OK, I have yet to get my MH, much less pull my toad.

But, as soon as I read the OP's post, this is exactly what I was thinking. Seems to me, sounds like exaggerated classic Porsche 911 handling believe it or not.........

What do you think that I raced?

Geosman · 01-12-2015, 05:42 PM

Here we go with some best advice. I had the same issue with my 23' on a Ford frame. Ford uses a floating suspension with twin I beam front suspension that likes to kneel when you turn. The hitch extension beyond the rear axle essentially orbits in an opposite direction to the way you want to turn and throws the steering opposite to where you are steering the RV. The result is truly capable of filling your pants! I started gyrating so violently on cupped asphalt that I had to slow down to 45 mph to keep things stable. I found a solution with a rear stabilizer from Blue Ox the forms a rigid link between the rear differential and the frame. This fixed the wiggle at the ass end caused by water tank sloshing. (its best to pull a dinghy with minimal water in the tank to help reduce this effect). I also added Air bladders to the front coil springs to stiffen up the front suspension and stop the kneeling on turns. My roadmaster Falcon 2 tow bar assembly has a big allen wrench tension adjustment and with a little extra twist, it takes just a bit more force to make a direction change. The 2" hitch socket allows for some more slop and can be tightened up using a "C" clamp centered through a secondary hitch hole in the side of the hitch to keep it clamped tight in the box and eliminate another source that can cause this "tail wagging" issue. Checking air pressure in all tires to 65 psi makes them hard but helps reduce drift when a truck passes and makes pulling the Dinghy a pleasure. I've had no issues since making these changes. (If you do not have a rear camera on your rig consider getting one installed. It's worth it. Also until you get used to pulling the dinghy you might try a piece of white masking tape top center on the steering wheel. It should be visible to the camera or anyone at the back of the RV to say how the steering is working on different road surfaces. My bet is that it will stay top dead center once you get the wiggle out of the ass of that RV.