Steering Shimmy 35-45mph (Video)

dchawk81

Well-Known Member
Thread starter #1
My Cascadia has a shimmy in the wheel from about 35-45mph. It's at all speeds really, but that's where it's worse. I made a short video. Excuse my loud voice. I wasn't sure how well the audio would be picked up since it was just my phone.


Any thoughts on the cause? Our local yard mechanics don't know what it is. They replaced the drag link and checked the bearings and such. They said everything seems good that they have the ability to tell. It's at our main OC now for an oil change cycle PM. If they actually relayed my message they should be checking it out up there but in the meantime I figured I'd ask here and call them up with any thoughts you all might have.

Our techs also claim to have replaced both steer tires but it was one then another. Not at the same time. They also would not have reused the Alcoa wheels because they swap entire assemblies down here.

Thanks in advance!
 

r3gulator3

Friendly Neighborhood Former Technician
Staff member
Supporter
#9
@dchawk81 - rub your hand in and out across the tread of both steer tires. If it's smooth, it's not an alignment issue. If it feels rough in one direction (in or out) - that's called "feathering" - then you have an alignment issue.

I'm betting you don't. The vibration you're describing is usually an unbalanced tire, although a loose wheel bearing in one or the other side of the steer axle can do it too. I had a Centramatic wheel balancer die and cause that one time too.
Dude you don’t see him sawing on the wheel in the video? If your truck pulls that bad, you got an alignment problem.
 

r3gulator3

Friendly Neighborhood Former Technician
Staff member
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#16
It does have an alignment issue but the shaking in the wheel predates that. It used to be shaky yet straight as an arrow.
Hmmm, you don’t say, that alignment issue is probably causing uneven wear, and that could be where the unbalance comes from or if you have centrimatics one has gone wonky.
 

r3gulator3

Friendly Neighborhood Former Technician
Staff member
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#21
Snap a pic of your tread and slowly post it, I’d like to see it if you don’t mind.
 

Injun

Rabid Squaw
Staff member
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#29
Whenever we have steering shake, we always go to the steer axle without consideration to the rest. Make sure you have ALL the wheel bearings checked. I had a similar shake on my ProStar and it ended up being caused by the drive wheel bearings. All of them were shot and I had to get a spindle replaced. Also, check the torsion bars back there.

Most large carriers don't bother balancing tires. They just slap them on and send you down the road. This could be a source also.
 

Sinister

Order of The Gilded Flip Flop
Staff member
Supporter
#7
Better question is does it even matter?

I mean are the self righteous megafleet mechanics going to listen to a lowly megafleet driver?
Operating out of a single terminal every single day SHOULD build some sort of relationship.

In someone like @Mike case where you bounced around all the time things might be quite different.
 

ironpony

Professional Pot-Stirrer
Supporter
#10
Dude you don’t see him sawing on the wheel in the video? If your truck pulls that bad, you got an alignment problem.
Check the friggin' tires. That dead Centramatic had me doing the same thing. If there's an alignment issue, there will be feathering.
 

mndriver

curmudgeon extraordinare
Supporter
#25
I borrowed this truck over a year ago and it was shaking then. It was assigned to me several months ago and it still shook. It's been through several sets of steers unless they keep lying to me and didn't really change them. The shaking never changed.

I would have thought at some point it would have stopped shaking if it was a tire balance issue. They possibly couldn't all be bad.

Like I said it was shaking even when the alignment was good.

You might be onto something with the bearings but I don't recall in cars ever having a bad bearing that smoothed out more at highway speed. It was always worse the faster you went.

If it's still there and the tires have been changed repeatedly...

What's the definition of insanity?
 
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