Scary Handling Problem

[DunnInn]

First the equipment:
2009 Winnebago 29T class C on 2008 Ford E450 with V10 Triton
2007 Jeep Liberty with 4 wheel drive
Blue Ox Tow Bar and Tow Plate
Brake Buddy

Now the problem:
When driving the Winnebago or Jeep separately, they do fine. When you hook them together, it becomes a white knuckle experience. When the toad is hooked up, driving at city speeds, the steering on the RV seems stiff and doesn’t try to return to center after a turn. With the toad hooked up, driving at highway speeds, when I try to correct for a wind gust or a truck passing, the RV seems sluggish in responding then overcorrects and must be corrected back. This leads to overcorrection to the left followed by overcorrection to the right and this continues for several cycles. Then it’s back to a constant wandering between the lines. The tow bar handles are both in the locked position and there is no slippage in the bar. The alignment on the Jeep checked out OK. Also had the shocks on the RV checked – they’re OK. No oversized tires on the vehicles. Sure would like to find an INEXPENSIVE solution to this problem. Any suggestions?

[DunnInn]

Finished installing front and rear sway bars. It did make a difference. Only time it's really white knuckle now is when trucks go around. Have to say, it still drives different when the toad is hooked up. Steering seems more stiff when the toad is there. Right now, I'm just pondering.

[DunnInn]

Since the front weight was done without me in the rv, I'm getting closer to that 75% mark. I think all the tanks are behind the rear wheels. Why they did that, I'll never know. Somebody had their head somewhere it shouldn't have been. The spare is in the back storage compartment. The generator is also in the back. Guess I'll have to think some on where and how I could possibly move some of this stuff.

[TyroneandGladys]

You are 69.6% of rated front axle weight the bare minimum IMHO is 75% and anything up to 95% would help. To get 75% you need to get 270 more pounds on the front. I would try to move 520 pounds and that would get you to 80%. How do you do that? Keep in mind that any weight behind the rear axle takes weight off of the front axle.
Is your water tank in front of the rear axle or behind the axle? If in front make sure it is full if it is behind carry the bare minimum you need while driving and fill at destinations. If your black and grey tanks are behind the rear axle keep them dumped. Move anything in cabinets and storage areas that is behind the rear axle as far as you can forward. Heavy stuff up front and bulky stuff to the back under the dinette seats are great for this. Does anyone ride behind the rear axle? Your cab over area can hold 150 pounds no problem. Yes it is hassle to remove the chairs for example from your overhead at night but it might be necessary. I do not recommend telling wife she needs to gain weight. After you have done this reweigh and if you are over 75% then hook the Jeep back up and see how it does.

[rcase13]

TyroneandGladys wrote:

DunnInn wrote:
Weighed it a while back -
front axle - 3480
rear axle - 8420
I'll have to look at the tire sizes tomorrow.

What is the gross axle weight rating for the front axle and what is it for the rear?
I think you are very close to be underloaded on the front axle

I think he is under loaded on the front end. If what I read is true the manufacturer wants minimum 32% on front axle. His numbers above would put him at 29% on the front axle. Mine is very similar and it also is squirrely on the road. I just got mine and haven't check pressures or gotten it aligned. I hope those two things will fix it. I can tell you if it was mine I would replace all 6 tires with good name brand tires. The grand it would cost me would be worth the peace of mind.

[DunnInn]

Per sticker on door, GAWR front 5000, rear 9500.

[TyroneandGladys]

DunnInn wrote:
Weighed it a while back -
front axle - 3480
rear axle - 8420
I'll have to look at the tire sizes tomorrow.

What is the gross axle weight rating for the front axle and what is it for the rear?
I think you are very close to be underloaded on the front axle

[j-d]

What condition are all the tires in? I ask because I'd be tempted to get the four across the back alike and a matching pair on the front.
Most of what I've read says that your rear duals should be set at the same pressure across all four of them. But I saw something recently that made sense, which was... The Inners should never be at higher pressure than the Outers...
This relates to CapriRacer's comment: If the Inners are "bigger" (and higher pressure would make them effectively bigger) than the Outers, then your coach is riding on a narrower rear track than if the Outers have their share of the load.

[CapriRacer]

DunnInn wrote:
.......The outside backs are Michelins. The inside backs and the fronts are Goodyears. Could this cause any of what we are seeing?

Yes! If the dualed tires are not the same diameter, one is carrying more load than the other.

[DunnInn]

Weighed it a while back -
front axle - 3480
rear axle - 8420
I'll have to look at the tire sizes tomorrow.

[TyroneandGladys]

DunnInn wrote:
FINALLY back to working on installing the heavier sway bars. While working on this, a thought occurred. All 6 tires are not the same. The outside backs are Michelins. The inside backs and the fronts are Goodyears. Could this cause any of what we are seeing?

Anything is possible are they the same size? And have you weighed it yet?

[DunnInn]

FINALLY back to working on installing the heavier sway bars. While working on this, a thought occurred. All 6 tires are not the same. The outside backs are Michelins. The inside backs and the fronts are Goodyears. Could this cause any of what we are seeing?

[j-d]

Any sideways wobble in the tow setup will give the RV a bad time. 1/2" doesn't sound like much but it's a lot when it comes to tracking. An otherwise tight baseplate and towbar can seem to be the culprit if there's a wobbly drop receiver.

[TyroneandGladys]

desertrek wrote:
TyroneandGladys,

I agree that weight distribution plays a big part in how a rig handles but in this case it has no affect. When towing 4 down (a toad) there is virtually no tongue weight at all. The amount of force it takes to turn the front of the towed vehicle is the major affect that towing a toad has on the rig. The rest is all up to how the rig handles on it's own. The side to side force can cause a tail wagging affect which is exaggerated at the steering wheel. There will be little to no change in the weight distibution with the toad connected If it is on all 4 wheels. How much is loaded to the rear inside the RV will change the front wheel weight ratio though. Which you are absolutely right, can have an adverse affect even with a toad.

IMHO Even if there virtually no tongue weight at all from the Jeep if the RV is right at the break point 20 pounds could push it over the line from almost to little to too little. Second 20 pounds that far behind the axle will take more than 20 pounds off the front because of the see saw effect. Third the RV could already have the front axle under loaded and the extra handling stresses of towing the Jeep could be more than it can handle.

[desertrek]

TyroneandGladys,

I agree that weight distribution plays a big part in how a rig handles but in this case it has no affect. When towing 4 down (a toad) there is virtually no tongue weight at all. The amount of force it takes to turn the front of the towed vehicle is the major affect that towing a toad has on the rig. The rest is all up to how the rig handles on it's own. The side to side force can cause a tail wagging affect which is exaggerated at the steering wheel. There will be little to no change in the weight distibution with the toad connected If it is on all 4 wheels. How much is loaded to the rear inside the RV will change the front wheel weight ratio though. Which you are absolutely right, can have an adverse affect even with a toad.

[j-d]

T'n'G You are SO right. Weight and tire pressure, then alignment. The Basics. THEN see what else might help. It can be all gussied up with sway and track bars, steering stabilizers, shocks... and still won't be right unless it's aligned and loaded well with correct pressures.