Tons of vibration in steering wheel?

[Brewtal66]

Hey gang,

So this is a little off the topic of Lateral-G, but I've been fixing up a 1991 Fleetwood Pace Arrow motorhome. It's a Chevy P-30 chassis.

Recently, I started going for test drives, in it, and there is a TON of vibration and feedback in the steering wheel. On this rig, there is the frame, then a large stamped steel structure that comes up that holds the steering wheel, brake pedal assembly and gas pedal. Then they build the motorhome around that.

I've visually inspected just about everything I could, and didn't see anything wrong. There was one support brace broke, but I welded it up and it didn't do anything. I've looked under the hood, under the dash, and under the rig itself and don't see anything majorly wrong.

When driving down the road, the steering wheel is smooth, it's only when you hit a bump/crack does it get that vibration in the wheel. How I explain it is like a stiff metal pole in the ground, and you pull the top and let it go, it just vibrates back and forth like crazy. I even had the steering column rebuilt(for a different issue).

Lastly, I replaced the steering stabilizer with a good Monroe brand stabilizer, and this even has the "Safe T Plus" stabilizer attached to the steering as well.

I'm now starting to think it's something in the suspension/steering itself, but I'm not sure what it would be. Sorry for the long-winded explanation, just tried to do my homework first.

Thanks for any suggestions!

[Vince@Meanstreets]

With the vehicle in a safe position have someone slightly turn the wheel left and right. There is a slack point right before you feel resistance. Try to have the wheel person stay with in that point maybe a bit over.
Crawl under and visually inspect the linkage. I bet you have something worn or getting loose. Look for up and down play as well as no movement while the box is turning.
Also pull your front wheels and have them balanced and check for bends in the wheel or tread separation. For sits and giggles.

I know it's a truck but Look up jeep death wobble for other tests you can try.

[Vince@Meanstreets]

Where was this support brace?

[Brewtal66]

Originally Posted by Vince@MSperfab

With the vehicle in a safe position have someone slightly turn the wheel left and right. There is a slack point right before you feel resistance. Try to have the wheel person stay with in that point maybe a bit over.
Crawl under and visually inspect the linkage. I bet you have something worn or getting loose. Look for up and down play as well as no movement while the box is turning.
Also pull your front wheels and have them balanced and check for bends in the wheel or tread separation. For sits and giggles.

I know it's a truck but Look up jeep death wobble for other tests you can try.

I'll do that this week and see what I can find. I'm thinking something is worn out too...nothing has been replaced under there, but I'm not sure on the mileage since the odometer doesn't work, but I know it has probably 60K or so on it. I replaced the front shocks, which were still the originals...and they were blown out badly haha.

Originally Posted by Vince@MSperfab

Where was this support brace?

It's under the hood, but it was just part of the tubing that holds the entire front end together, the motorhome part, not the chassis part.

[BMR Sales]

How are the tires? Motorhome Tires will gain flatspots as they sit so much

[Shmoov69]

is the vibration the "death wobble" or more like a tire out of balance? My 06 F250 had a horrible death wobble on the highway that moved the steering wheel back and forth insanely fast about 30* or so if you were pulling a trailer. I ended up putting a bigger stabilizer shock on it and it "masked" it enough to be safe again. It would only do it if there was an empty trailer on the back. Only thing I could think of is that it put "just enough" weight to make the front at the right point to show the design flaw.
Maybe even unhook the stabilizer to see if it makes it worse?

[JpRngr]

Jack up one front wheel at a time and shake the wheel back and forth at 3 and 9 o'clock and at 12 and 6 o'clock. Look and feel for excess play in your steering and suspension. Sometimes you even have to put a long pry bar under the tire and lift up and down to check for play in the ball joints.

Corey

[Brewtal66]

Originally Posted by BMR Sales

How are the tires? Motorhome Tires will gain flatspots as they sit so much

Tires are new...all of them. I just put those on about 2 months ago.

Originally Posted by Shmoov69

is the vibration the "death wobble" or more like a tire out of balance? My 06 F250 had a horrible death wobble on the highway that moved the steering wheel back and forth insanely fast about 30* or so if you were pulling a trailer. I ended up putting a bigger stabilizer shock on it and it "masked" it enough to be safe again. It would only do it if there was an empty trailer on the back. Only thing I could think of is that it put "just enough" weight to make the front at the right point to show the design flaw.
Maybe even unhook the stabilizer to see if it makes it worse?

I don't think so since it has nothing to do with speed, like an out of balance tire. This is is only when I hit a bump or crack in the road, does it get the vibration. Definitely not a wobble.

I did replace that stabilizer shock and it made an improvement, about 50% better. Before that it was unbearable, now it's just annoying lol

Originally Posted by JpRngr

Jack up one front wheel at a time and shake the wheel back and forth at 3 and 9 o'clock and at 12 and 6 o'clock. Look and feel for excess play in your steering and suspension. Sometimes you even have to put a long pry bar under the tire and lift up and down to check for play in the ball joints.

Corey

I'll do that along with having somebody turning the wheel and looking for movement as well. Sounds like I just need to get under this rig again and start poking around!

[David Pozzi]

I had a Winnebago 23' class A that had a lot of steering column jerk when I hit a big bump. It felt like someone hammering on the steering column. It didn't result in a left or right tug, just WHAM! front to rear movement of the steering column when a big bump was hit.

Everything was in good shape, the prev owner installed a stability system with two large coil springs attached from the bottom of the A arm to the spindle on each side that may have helped reduce it. It holds the spindle on-center. The coach was easily blown left and right from air spilling off other cars. The front suspension does not have a huge weight capacity, so to carry the load, they balance most of the weight over the rear axle. This makes the front end relatively lightly loaded and it affects directional stability. The tires are a high profile with soft sidewalls in an attempt to soften the ride. This reduces directional stability a little.

[glassman]

yeah, you could have a bad "new" tire. My 23' class c would have a "shimmy" from one of the inner rear tires, new ones would fix the problem, but it would still come back with time (and it didn't sit much at all, so no flat spots).