Steering problem

[daveandviv]

I am still doing some research and will need to get the coach weight. I have a W-24 frame and the tires are 235/80R/ 22.5 (XRV)

[JohnRR]

Originally Posted by daveandviv

The Manual suggested 110 for the front..... 100psi for the rear, so I went under that already, (100psi) but I could lower the psi by another 10psi on the front to see if that does anything.

I have basically the same set up a you except a 38', my body decal suggests 90psi rear and 100 front, no other suspension parts added and it drives straight as an arrow. I would think I am also heavier than you as well.

I tried 105 in the front going to the iRV2 rally last summer and it picked up a very distinctive wander. I just set them back down for tomorrows season shake down trip.

[daveandviv]

I had the coach weighed and according to the chart for my 235/80/22.5 was 85 for the front and rear. So I was running a little high on the pressure. I will try knocking this down to 85psi and check out the adjustment very soon to see if it helped the sloop in the steering wheel.

[mrrob1]

Tejay gave some very good advice.I had the same problem that you have.I went to a local rv shop and was told that I needed four new shocks {$875} and rear airbags{$1100}.I read this post and did some checking for myself.My rear swaybar bushings were worn out. I replaced them myself and it cost me only $96.00. Got the bushings from the Ford dealer.

[daveandviv]

Pressure is now at 85 and it still has play in the steering wheel and is wandering side to side making it hard to follow a straight line. I guess I will put a Trac Bar in the rear and after that ????????????????

[DAN L]

Originally Posted by daveandviv

Pressure is now at 85 and it still has play in the steering wheel and is wandering side to side making it hard to follow a straight line. I guess I will put a Trac Bar in the rear and after that ????????????????

a track bar from brazel's made a big improvement in the handling of my rig.

[TeJay]

If you have any skills or access to some stuff you can build your own track bar and save a few hundred dollars. Check this sight.

Oemy's Web Site - DIY Trac Bar

TeJay

[Harvard]

Tejay is right on where he suggests more +caster. Heres a link to my experience with caster. E350/E450 Handling Problems are caused by too little + CASTER

Buy as much caster as you can afford.

[TeJay]

Harvard,
Thanks. It's always nice when a suggestion helps others with problems. Here's a little more information as to why + caster effects the vehicle the way it does. A Chopper (motorcycle) has excessive + caster. Consider the axis of rotation for the chopper. The top of that point of rotation is tilted way back. If you pushed it forward and made it vertical you would have 0 caster. Push it further forward and you have - caster. If you are old enough you might remember those little red wagons. You never, never wanted to roll down a steep hill because the slightest turn of the handle and you jackknifed and wrecked. Those were set up with zero caster. With positive caster the weight of the vehicle is actually pushing down on the wheels forcing them in a straight ahead direction. When you turn the steering wheel you are actually lifting the weight of the front of the vehicle. After you make a turn and release the steering wheel it is the weight that is forcing the steering wheel to return to the center position. That's why + caster helps with tracking and it also resists wind forces trying to push the front around. A food cart caster is way negative. When you push the cart the weight turns the wheel around and trails the cart. You can turn the cart and that's why it's negative caster. More positive caster is acceptable today because the amount of effort to turn and lift all that weight is negated by the power steering system.
I hope this makes more sense. I've got an old pick-up that won't track correctly. The alignment guy said that the caster is within specs. He replaced the pitman arm because it was worn. This helped but it still will not track well. I'm going to ask him to increase the caster by 2 more degrees.

TeJay

[Harvard]

Originally Posted by TeJay

....
I've got an old pick-up that won't track correctly. The alignment guy said that the caster is within specs. He replaced the pitman arm because it was worn. This helped but it still will not track well. I'm going to ask him to increase the caster by 2 more degrees.

TeJay

This is crux of the matter, setting Toe and Camber to MID spec is a given. But, when it comes to caster more +caster is better WITHIN spec. My vehicle has a Caster Spec from about +1.5 to +7.0 and I went from +3.5 to +5.5.

IMO the lower +caster range is good for a city deliver van but for a highway driven vehicle you want to be on the high range of +caster.

[daveandviv]

Would the +Castor adjustment ware the tires differently

[terry735001]

there is a adjustment on the steering box i am sure you can find the right info
just pull that adjustment in slowly if you do think that is it

[TeJay]

The steering gear adjustment that you are referring to is the worm gear adjustment. I have adjusted that and it still wants to wander.

Since caster is tilting the axis of wheel rotation either away from you or towards you it will not effect tire wear. Camber and toe are angles that cause tire ware.

TeJay

[daveandviv]

Terry......The shop told me it did not have an adjustment