Discovery 40 G - Vibration and pull to the right

[jondrew55]

Probably two unrelated things. My Discovery definitely pulls to the right. I'm convinced at this point it's more than just road crown and gets tiring after a couple of hours of driving. Headed to an alignment shop to get it checked out.

But I also notice a definite vibration around 40 mph. It's smooth slower than that and smooth after I pass thru 45 or so. Not sure it it's a tire balance issue or what. Hope I don't have to go to 2 different places.

[windsorbill]

Have you weighed the coach? What pressure in tires are you running? Alignment is definitely on the check list, but don't forget the pressures. What brand tires?

[Lt Dan]

I had the same pulling to the right issue on our XC chassis. I had Freightliner check the ride height and all was normal. After I had the front end aligned, there was a major difference in the steering. It runs straight and true now. If the ride height is off on one wheel it can cause pulling, so get that checked first before you have it aligned.

[Johnnyw]

For the vibration, check your ujoints. Had similar issue last year. changed ujoint, everything smooth!

[windsorbill]

I was on another site earlier, and the owner had a defective tire. He either rotated or replaced them and all seems good now.

[dan-nickie]

When I was dealing with Freightliner on these issues comma they told me that the first thing to do is get the ride height set properly. Incorrect ride height could cause both of those issues.

[Cat320]

I had a similar issue...tires were way out of balance.

[Tha_Rooster]

Originally Posted by jondrew

Probably two unrelated things. My Discovery definitely pulls to the right. I'm convinced at this point it's more than just road crown and gets tiring after a couple of hours of driving. Headed to an alignment shop to get it checked out.



But I also notice a definite vibration around 40 mph. It's smooth slower than that and smooth after I pass thru 45 or so. Not sure it it's a tire balance issue or what. Hope I don't have to go to 2 different places.

Mine vibrated and pulled the the right just before BOOM passenger front tire blew.

[jondrew55]

Like I said, I'm going to start by getting an alignment check. I'm pretty sure the shop I'm going to can do a 4-wheel weight. Next step would be tire balance.

By the way, that vibration at 40 MPH is kind of interesting. It's not just a vibration, it's almost like that sound you get when you drive with your rear windows open in your car. It's almost like a "womp, womp, womp" that you feel in your ears and chest. But it goes away after 40.

[Fiesta48]

Drove 2 new Freightliner XC chassis's, both pulled to the right. Alignment fixed it.

[FrankenHome]

Originally Posted by jondrew

Like I said, I'm going to start by getting an alignment check. I'm pretty sure the shop I'm going to can do a 4-wheel weight. Next step would be tire balance.

By the way, that vibration at 40 MPH is kind of interesting. It's not just a vibration, it's almost like that sound you get when you drive with your rear windows open in your car. It's almost like a "womp, womp, womp" that you feel in your ears and chest. But it goes away after 40.

If it goes away over 40 mph it is unlikely that's a tire. You may have two separate problems but I would check the wheel bearings and the driveshaft u-joints. A bad u-joints can cause a vibration then seemingly go away at a higher speed. A bad wheel bearing usually causes a noticeable growling sound that the only increases as speed increases bug I wouldn't rule it out until they're checked. And of course as you already know you may a more obvious problem with a tire. Please let us know what you find out is the cause and the cure. Thanks.

[jondrew55]

Well I'm $550 lighter in the wallet and I did get a 4-wheel weight. But despite a computer balance and wheel rotation the vibration is still there. Hard to tell if the pull to the right is fixed or not since it got quite windy on the ride home. I also heard something hitting the bottom of the coach on the highway. It appears to come from the right front side and I'm wondering if I threw some wheel weights. Doesn't matter, I felt the vibration at around 40-45 again before and after that thunk happened on the road.

The alignment shop was very busy today so I did not go back there. I'm going to go for another ride tomorrow, hopefully when the wind dies down to get a better feel. I'll give the shop manager a call on Monday. He was not in the shop today.

I'm also going to calculate the proper tire inflation pressure now that I have it weighed. See what difference that makes.

I'm afraid I may be chasing something else down as you suggested (a tire or driveshaft u bolt. I'd have imagined these guys should have checked the wheel bearings since that is what they do there, but it will be worth asking again.

I'll post an update when I have one.

Originally Posted by FrankenHome

If it goes away over 40 mph it is unlikely that's a tire. You may have two separate problems but I would check the wheel bearings and the driveshaft u-joints. A bad u-joints can cause a vibration then seemingly go away at a higher speed. A bad wheel bearing usually causes a noticeable growling sound that the only increases as speed increases bug I wouldn't rule it out until they're checked. And of course as you already know you may a more obvious problem with a tire. Please let us know what you find out is the cause and the cure. Thanks.

[FrankenHome]

Originally Posted by jondrew

Well I'm $550 lighter in the wallet and I did get a 4-wheel weight. But despite a computer balance and wheel rotation the vibration is still there. Hard to tell if the pull to the right is fixed or not since it got quite windy on the ride home. I also heard something hitting the bottom of the coach on the highway. It appears to come from the right front side and I'm wondering if I threw some wheel weights. Doesn't matter, I felt the vibration at around 40-45 again before and after that thunk happened on the road.

The alignment shop was very busy today so I did not go back there. I'm going to go for another ride tomorrow, hopefully when the wind dies down to get a better feel. I'll give the shop manager a call on Monday. He was not in the shop today.

I'm also going to calculate the proper tire inflation pressure now that I have it weighed. See what difference that makes.

I'm afraid I may be chasing something else down as you suggested (a tire or driveshaft u bolt. I'd have imagined these guys should have checked the wheel bearings since that is what they do there, but it will be worth asking again.

I'll post an update when I have one.

jondrew, sorry for the typos in my post. I made edits but apparently they were not saved. I hope you find the problem soon and it's not too serious. Good luck

[windsorbill]

I'm curious, what brand tires do you have?