Go Back   Thor Forums > Thor Tech Forums > Maintenance and Repair
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 04-01-2017, 11:50 PM   #1
Member
 
Brand: Thor Motor Coach
Model: Hurricane 35M
State: Virginia
Posts: 46
THOR #6664
Random Shimmy

Looking for some feedback. I have a random shimmy/vibration in the steering wheel around 70 mph. Doesn't happen at any other speed, and is not consistent. I've had an alignment and Safe T Plus installed. Only other thing I can think to do is high speed balance on front tires. It's odd to me that it's random, and not road surface related, and only at that speed. Hoping some folks smarter than me have some advice.

Just in case signature doesn't come thru, this is on a 2017 Hurricane 35M. Thanks!
__________________

__________________
Jmccombe is offline   Reply With Quote
Old 04-02-2017, 12:34 AM   #2
Senior Member
 
Miramar Owner's Avatar
 
Brand: Thor Motor Coach
Model: Miramar 34.4
State: Iowa
Posts: 661
THOR #4488
Since you mention it's in your steering wheel it does sound like a balance issue. Could be a separation in the steel belt. You could do a spin balance or move the front tires to the rear.
__________________

__________________
Miramar Owner is offline   Reply With Quote
Old 04-02-2017, 12:43 AM   #3
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,962
THOR #2121
It could be front tires out of balance.

It's not that unusual for many vehicles to have a critical speed in that 70 MPH range where any lack of balance will magnify. It's caused by the natural frequency of the suspension (relative to vehicle) matching the rotating speed of the front tires, which is the forcing frequency. When the two match you get resonance, which is a fancy word for greatest vibration you can feel through steering wheel. If really bad the entire vehicle may vibrate as a wheel skips up and down off pavement.

In my van the worst speed is around 73 or 74 MPH, so I try to drive above or below that speed.

You can test if it's this by driving to speed where vibration is worse, and if you feel safe doing it, accelerate another 5 MPH or so to see if it starts to go away. Then on way back past the critical speed you should feel it get stronger again.

If your vibration doesn't diminish with even higher speed, then it's likely something else.


P.S. -- Shocks limit this effect, so may want to check to make sure they look good and are tight.
__________________
Chance is offline   Reply With Quote
Old 04-02-2017, 03:07 AM   #4
Senior Member
 
Mr Sunshine's Avatar
 
Brand: Thor Motor Coach
Model: 2016 Vegas 25.2
State: Florida
Posts: 1,980
THOR #1589
My last coach had a slightly bent wheel which caused a vibration over a certain speed. The tire folks tried in vain to spin balance it on the front. Switching it to the back helped, but didn't completely solve it. If I kept it under 65 mph, it was ok with that wheel on the back.
Maybe the real message is to slow down and enjoy the journey?
__________________
They say that not all who wander are lost, but sometimes I am just lost!
Mr Sunshine is offline   Reply With Quote
Old 04-02-2017, 03:45 PM   #5
Senior Member
 
Brand: Thor Motor Coach
Model: 37GT
State: Florida
Posts: 809
THOR #5246
Quote:
Originally Posted by Miramar Owner View Post
Since you mention it's in your steering wheel it does sound like a balance issue. Could be a separation in the steel belt. You could do a spin balance or move the front tires to the rear.
It could be the beginning of a belt separation, or if one of your front wheels were balanced using more than one weight one or more of them may have came off. I would go to a good tire shop and have both inspected. Steer axle tire issues are nothing to mess around with IMHO.
__________________
Full Time in 2017 Newmar Ventana 4369
pulling a 24' enclosed (Mini Cooper/Harley/Kayak)
(traded 2014 Thor Challenger)
US Army 70-73 Retired LEO
Joe-FL is offline   Reply With Quote
Old 04-02-2017, 07:07 PM   #6
Senior Member
 
Brand: Thor Motor Coach
Model: Windsport 31S
State: Florida
Posts: 303
THOR #4443
Commonly a belt separation will cause a low speed shimmy. That being said don't excuse a defective part even though its a new coach.
__________________

__________________
penguin is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 04:54 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2
×