Violent Shaking at Highway Speed

Floridakamper · 10-01-2016, 07:12 PM

Traveling today, towing our Equinox 4 down, I was merging into traffic with construction in progress and no shoulder. I got up to 60 mph and the whole motorhome started shaking violently. I slowed and about a mile down the road there was barely enough room to get off the road. I knew I was going to find a shredded tire somewhere but nothing. Checked tire pressures and wheel temps but everything appeared normal. Checked my tow bar and base plate and all seemed OK. I disconnected the car and my wife followed me off the next exit. In a Lowe's parking lot I checked everything again. I couldn’t find anything wrong. Got back on the expressway and my wife followed for about 100 uneventful miles. At a rest area I hooked the car up again and towed for another 150 uneventful miles. Not sure what happened.

Ranger Smith · 10-01-2016, 07:20 PM

It was probably those divits they put on the side of the lane to let you know your going off to the side of the road. Sometimes in construction area's when they shift lanes slightly they don't fill them in.

mel s · 10-01-2016, 07:29 PM

Quote:

Originally Posted by Floridakamper

Traveling today, towing our Equinox 4 down, I was merging into traffic with construction in progress and no shoulder. I got up to 60 mph and the whole motorhome started shaking violently. I slowed and about a mile down the road there was barely enough room to get off the road. I knew I was going to find a shredded tire somewhere but nothing. Checked tire pressures and wheel temps but everything appeared normal. Checked my tow bar and base plate and all seemed OK. I disconnected the car and my wife followed me off the next exit. In a Lowe's parking lot I checked everything again. I couldn’t find anything wrong. Got back on the expressway and my wife followed for about 100 uneventful miles. At a rest area I hooked the car up again and towed for another 150 uneventful miles. Not sure what happened.

The steering geometry of some toads can cause the front wheels on the toad to wobble if the toad is pulled through/over certain road conditions, (bumps, ruts, etc.) ...OR if either the right or left wheels of the toad are allowed to drop onto a low shoulder.

Usually simply stopping the coach and then driving on stops the wobble until the next wobble incident.

(Google "chevy equinox death wobble" for more information).

Floridakamper · 10-01-2016, 07:30 PM

Quote:

Originally Posted by Ranger Smith

It was probably those divits they put on the side of the lane

Been there, done that.... This was sort of like that but by a multiple of 10.

twinboat · 10-01-2016, 07:33 PM

You may have hit , just the right combination of conditions, to set up a death wobble.

Death wobble is the violent movement of the towed cars front tires, right to left. They shake back and forth, passing the straight ahead position too fast.

Slowing down or stopping and then proceding again usually cures it.

If your car has high mileage, and some wear on the front suspension, it may contribute to the problem.

Floridakamper · 10-01-2016, 07:34 PM

Quote:

Originally Posted by mel s

The steering geometry of some toads can cause the front wheels on the t0ad to wobble if the toad is pulled through/over certain road conditions, (bumps, ruts, etc.)....usually simply stopping and then driving on stops the wobble.
(Google "chevy equinox death wobble" for more information).

I hadn't heard of the "Equinox Death Wobble" but I think it's an appropriate name. I think you may have hit the nail on the head. Scary stuff.

firedoc · 10-01-2016, 07:46 PM

Apparently it happens more frequently with the electric power steering rather than hydrolic.. Your case?

Americanrascal · 10-01-2016, 07:55 PM

I was towing with a dolly and Focus on I-10 across southern AZ yesterday in a 2016 Adventurer 38Q like Floridakamper's rig (F-53 28K lbs). While moving along at about 62 mph we felt this violent shudder- it seemed to be towards the rear. Have been driving F-53's (this is our second) and towing this dolly for 3 years now about 35,000 miles and never had this sensation. Lasted about 4-5 seconds-- then as I backed off the throttle it went away. It was so violent it shut down the generator.

Since yesterday (500 more miles later) I've not experienced this issue again. I wondered if it was an earthquake as we were in the vicinity of the swarms on the Salton Sea but I found no record of one at the time. I also immediately wondered I had blown one of the rear tires- nope all OK. I have crawled all under the rig looking for a broken or loose part-- nothing.

As violent as it was I am a bit worried.

99Adven · 10-01-2016, 08:38 PM

I've had this happen but have had a big piece of tar stuck to a tire that causes everything to shake pretty good. Once the tar gets flung off, it quits shakin.

Jerry J · 10-01-2016, 10:18 PM

I've also had a piece of tar stick to a front tire that really shook the steering. It seems to have happened at a patch in a parking lot I was leaving that we stopped on and I turned the tire while stopped and then pulling out on the street. Really hard to scrape off the tire. Scary not knowing what was happening at the time.
Also another thought as we drove through a construction site that a rock stuck between the duals. Rear vibration with the very out of balance tires. The rock was big enough to jam between the tires. I had a heck of time getting that rock out. Maybe you had the same but the rock came out with the centrifugal force. Ideas anyway. Always a new surprise while rving.

SuperGewl · 10-01-2016, 11:29 PM

Sounds like you got the Cherokee death wobble. Actually I believe it all stems from the draw bar not being tight in the receiver, along with the front of the Toad being unloaded (slight lift on the suspension)
First thing to check is the draw bar, while unhooked, grab it and see if you can shake it back and forth and up and down in the receiver. If there is any movement then this is where to start. Get your self a Quiet Hitch from Roadmaster, if you are also using a drop bar or riser then you will need 2 of them.
Next line up the Toad behind the MH as if you are going to hook it up. Now take a measurement from the ground to the a fixed point on the bumper or hitch mount. Now hook up the Toad, now remeasure the Toad to the same point as before and see if they are the same. You may need to pull the toad around a few feet or so and then remeasure. If the distance has changed this will also add to the Death Wobble, especially if the number has gotten bigger( the coach is lifting the front end of the Toad).

All of this is very important due to most of todays Toads have Electric power Steering.
Hope this helps.

Floridakamper · 10-02-2016, 05:07 AM

Quote:

Originally Posted by SuperGewl

Actually I believe it all stems from the draw bar not being tight in the receiver, along with the front of the Toad being unloaded (slight lift on the suspension)

I do have have movement in the receiver. Thanks for the Quiet Hitch info. I've towed this car for 10 or 15K miles with a different MH. I had to use a 6 inch drop bar on the Newmar. This new Suncruiser sits a lot higher. When I picked it up, I measured and it looked like I needed a 10 inch drop, but the dealer only had an 8 inch. I read somewhere that you can be 3 inches high or low, so I purchased it. I think I'll replace it with a 10 inch that I can order. I guess it's just a coincidence that americanrascal also had a similar shaking incident with the same year, make and model MH, and he tows with a dolly.

RayJr · 10-02-2016, 07:00 AM

This is exactly why I'am reluctant to get a replacement for my 2005 Suzuki XL7, The old girl has 87,000 miles on it and I guess has been towed at least 55,000 miles, miles don't register when being towed. The Winnebago Journey has 58,000 miles on it and rarely do we travel without the car. That would include cross country from NJ to Cal twice and one flat tire on the XL7 that we towed through Chicago since no one let us know about the flat. Never ever, did I mention NEVER, have we had an issue with the toad. Just push the N on the transfer case switch put the key in Acc and away you go.

SuperGewl · 10-03-2016, 01:45 AM

Quote:

Originally Posted by Floridakamper

I do have have movement in the receiver. Thanks for the Quiet Hitch info. I've towed this car for 10 or 15K miles with a different MH. I had to use a 6 inch drop bar on the Newmar. This new Suncruiser sits a lot higher. When I picked it up, I measured and it looked like I needed a 10 inch drop, but the dealer only had an 8 inch. I read somewhere that you can be 3 inches high or low, so I purchased it. I think I'll replace it with a 10 inch that I can order. I guess it's just a coincidence that americanrascal also had a similar shaking incident with the same year, make and model MH, and he tows with a dolly.

My Sunstar sits high but I require NO drop at all. I'll have to measure and see how high it really is.

WyoFree · 10-04-2016, 07:53 PM

I've not had the problem with a motorhome but have in my SUV. It was like you guys are saying, it shook and felt like the tires were wobbling all over the road and was riding like I was in a lumber wagon. I got out and looked and saw mud on the wheels and side of the car, but nothing that would have caused this. And you have to understand, the car felt like it was shaking apart, it was nuts! I got back in and drove a few 100 feet and it felt the same way. So I got out and looked again, I had to have missed something for the car to act this way, I even popped the hood. But no joy, I drove home about 5 miles at 10 mph.

The next day I called the local dealer and explained what happened and he said two words "It's mud"! He said that I could bring it to him and be charge $100.00 bucks. Or I can go down to a car wash with the pressure washer wand and blow out the breaks and around the hubs.

I thought he was nuts until I did what he said and saw all the gunk come out of the wheels and under the car. I'd gone through a construction area with clay/mud and it built up around the breaks etc. I called the dealer back the next day and told him he was right! He said it may never happen again but it happens!

Don't know if this helps but I've been driver a lot of years and never had such a thing happen!!!