Shaking at 70+ mph

[teddyrevenge]

2006 Suburban. 34 inch tires. No lift, not even keys. Running out of ideas on whats wrong. At 70 mph the vehicle starts to shake. Very little noticeable in the steering wheel, instead more of a shaking up and down. There is no lead up to it. Just Boom. As soon as that speedometer hits 70 mph, it starts shaking. However its not a consistent shake. Sometimes its mild, sometimes its rough. But its never not there. Im not thinking its the tires because I've had those tires (not the same type, but those actual tires) on 3 different vehicles. Just swapped them around and none of the other trucks were shaking at any speeds. But the shaking gets worse the faster you go past 70.


List of things I have replaced so far and the shaking is still there.
-Upper/ Lower Ball Joints
-Tie Rods
- Pitman arm/ Idler Arm
- Passenger Side CV Axle --- Drivers Side has no slop
- Brand new Bilstein 4600 shocks all the way around w/ MOOG replacement springs since it had the 'helper' shocks
- Both Drive Shafts balanced with brand new U-Joints

At this point, I have no idea what to try next and would appreciate anything else that I can throw money at until its fixed.

 

[ramblinChet]

You have not balanced your tires or replaced them? That's the first thing I would have focused on.

 

[tplane2]

Sounds like you've hit all the usual suspects. Possibly wheel bearings or the actual steering box.

I'm sure you've done this, but lift one front wheel off the ground, grab it with both hands on opposite treads, then shake horizontally back and forth. That would be wheel bearings if they're loose, but rarely do they make things shake.

Is your tread pattern wearing unevenly?

 

[Gnarwhal]

Have you maybe dinged you driveline in the past? I haven't ever bent a driveline, but maybe it has a slight enough bend in it that you aren't feeling anything until you hit a higher speed?

Also, how old are the tires? I had a set of snow tires on my wife's minivan that the inner belts began to separate and it made them very unbalanced at higher speeds. What was weird is that they just started one day.. it wasn't gradual. Do you have access to another set of rims and tires you can throw on? That way you can eliminate the tires as a possibility?

 

[ChasingOurTrunks]

Bit of a longer shot, but have you been in any mud lately? I've had violent vibrations in my old jeep, and it turned out mud was caked on to the wheel; once I cleaned that off it got better but didn't go away, and that's because of even more mud on other moving parts. Once I cleaned the mud out fully, things settled back down (As much as they ever do in an old Jeep!)

The only other thing I'm wondering about is bushings. 2006 Burb is getting to the age where rubber would be perished, and swapping for poly bushings might make a huge difference where you can. Worn bushings can look good, and sometimes even feel good when you do a diagnostic, but play hell with the handling and feel of the vehicle once enough force gets into them (and a 7,000 lbs vehicle going 120 kph is a lot of force). Come to think of it, I wonder about that one CV you haven't replaced -- just because it's not showing wear in a driveway, doesn't mean it's not got a bit of wear that shows up at higher speeds?

Good luck tracking it down. I had a phantom vibration in my motorbike that I chased all season when I first got my bike. I swapped parts, balanced everything that could be balanced, and still there was a slight vibration in my footpegs. I finally found the solution -- a set of Dr. Scholls gel inserts in my riding boots.

No vibes now unless I'm getting low on oil and then I can feel it ever so slightly, so it's more like a diagnostic tool now!

 

[plh]

sounds like the Jeep Cherokee death wobble.

 

[Climber Rob]

2006 Suburban. 34 inch tires. No lift, not even keys. Running out of ideas on whats wrong. At 70 mph the vehicle starts to shake. Very little noticeable in the steering wheel, instead more of a shaking up and down. There is no lead up to it. Just Boom. As soon as that speedometer hits 70 mph, it starts shaking. However its not a consistent shake. Sometimes its mild, sometimes its rough. But its never not there. Im not thinking its the tires because I've had those tires (not the same type, but those actual tires) on 3 different vehicles. Just swapped them around and none of the other trucks were shaking at any speeds. But the shaking gets worse the faster you go past 70.


List of things I have replaced so far and the shaking is still there.
-Upper/ Lower Ball Joints
-Tie Rods
- Pitman arm/ Idler Arm
- Passenger Side CV Axle --- Drivers Side has no slop
- Brand new Bilstein 4600 shocks all the way around w/ MOOG replacement springs since it had the 'helper' shocks
- Both Drive Shafts balanced with brand new U-Joints

At this point, I have no idea what to try next and would appreciate anything else that I can throw money at until its fixed.

1. New tires
2. Check that wheels run true while the tires are off
3. All new bushings

 

[jbaucom]

Have you had the tires on the Suburban before? I ask because it could be that once you pass 70 mph, the frequency of vibration from the tires, which is normally pretty unnoticeable, matches a vehicle frequency that sets up a vibration. I may not be describing it in exact technical terms, but the gist of it is that maybe the tread pattern of your tires doesn't play well with that vehicle. The 2014 GM trucks had/have seemingly random issues with high speed shaking, and my 2014 did not suffer from any shakes until I put a set of General Grabber AT/X tires on. The tires took very little weight to balance and Discount Tire road force balanced them several times with no issues with excessive road force or any indication of a wheel or tire problem, however the truck still shook like crazy going down the interstate. I glass of ice water in the cup holder sounded like a cocktail shaker. Discount finally swapped the Grabbers for a set of Falken AT3W and the shakes went away - smooth as glass on the interstate at any speed.

 

[GoinBoardin]

Bent wheel?
I just swapped out some steel wheels bc two were bent and shook pretty bad at certain speeds. They wobbled side to side as they rotated. Tire shop did their best to balance it out but said I needed new wheels to fix it. Sometimes they'd run ok, hit a bump, and it would initiate a shake. The shake was variable day to day, some days tolerable, others not so much. Felt kind of like a hop. Smooth to 65mph but above that all bets were off. Worth checking anyway.

When you say you have swapped the tires onto other trucks, did you mount them on different wheels to do so, or did you keep them mounted on the same wheels?

 

[Todd780]

This happened to me with a 2000 Suburban. (Stock) It was coming from the rear and it turned out to be a rear U-Joint.

 

[calicamper]

Drive shaft is definitely a possibility. Had the same issue with my Sequoia. New Texas built drive line was like magic

 

[teddyrevenge]

Have you had the tires on the Suburban before? I ask because it could be that once you pass 70 mph, the frequency of vibration from the tires, which is normally pretty unnoticeable, matches a vehicle frequency that sets up a vibration. I may not be describing it in exact technical terms, but the gist of it is that maybe the tread pattern of your tires doesn't play well with that vehicle. The 2014 GM trucks had/have seemingly random issues with high speed shaking, and my 2014 did not suffer from any shakes until I put a set of General Grabber AT/X tires on. The tires took very little weight to balance and Discount Tire road force balanced them several times with no issues with excessive road force or any indication of a wheel or tire problem, however the truck still shook like crazy going down the interstate. I glass of ice water in the cup holder sounded like a cocktail shaker. Discount finally swapped the Grabbers for a set of Falken AT3W and the shakes went away - smooth as glass on the interstate at any speed.

I didnt think about the harmonics matching up like that. And the tires are mud terrain getting down to about half tread, so Im sure the harmonics on those are just atrocious. I would have thought brand new shocks and springs would have taken care of an issue like this but it looks like its time to go spend another $1000 on tires to see how they do.

To answer some other questions and comments.
-The very same tire and wheel were put on a 2005 GMC Sierra and a 1997 GMC K1500. Neither one of those shook at all with the tires on there. Also the wheels are good and the tires have even tread wear all around with no flat spots. The suburban shook with a different set of tires that were in bad need of replacement, but the shaking was not near as bad.
-Both front and rear driveshafts were taken to a reputable driveshaft shop. Both were balanced and brand new u-joints all around.

Current way forward is to get a new set of tires and new bushings all around. Except for the upper and lower control arm. Im going to hold off on that until its the last possible issue cause I really dont want to have to go through that process all over again.

 

[Willsfree]

Nothing sweeter than a new set of shoes...
My van has been shaking for a few months, finally had a tread blister/leak; my Hanooks had over 55k. Van is in the shop getting a 3" lift/shocks/leaf springs/brakes and four LT235/85R-16 TOYO A/T III E's. My experience is that old tires create noise/vibration/ poor handling etc. I'm looking forward to smooth miles this winter.

 

[Jacobm]

My 01 Yukon XL 2500 is doing the same thing, and I believe it started around the time I had the whole front end refreshed. I intend to have the tire balance checked (they're only 4000 miles old) and rotate them, but I did notice some uneven wear (probably due to driving on worn out front end components for 3000 miles). Driveline balance and shocks are my next suspects but tires are cheapest to rebalance and rule out. One also has a very slow leak that needs addressed.

 

[1stDeuce]

Checking wheels for mud buildup is a great first step.

Driveline issues like u-joints and bent driveshafts at 70mh would be more of a buzz (very high frequency) than "jumping up and down", which is something happening at the ~4x slower tire tire rotational frequency.

As you are running older tires that have been around the block a few times, I'd start by jacking each one up JUST off the ground and spinning it. You are looking for out of round and wobble. I would bet you have a couple of them out of round, or possibly with slightly bent rims. Big tires don't shake much for those sort of things at low speeds, but at higher speeds, they will start to bounce.
Could even be a couple of ever so slightly bent rear axles if your burb doesn't have a full floater, which acts the same as a bent wheel... Bent front wheel bearings are pretty unlikely, but it doesn't hurt to check...

Alternately, after making sure that none of them wobble due to bent wheel or axle issues, take them someplace that can road force balance them. All else being good, my guess is that you'll find road force variation is likely in excess of what the machine can compensate for. You can still tell it to do it's best, and they'll at least be better. Road force variation can even happen in a tire that appears round and runs true, fwiw.

Also, make sure they set the machine to perform a dynamic balance, not a static balance. Dynamic balance checks the tires for left/right imbalance in each tire that would cause a wobble at speed, and requires weights be added to both the inside and outside of the wheels. Many places set the machines to static balance and put all the weights on the inside of the wheel because customers don't want them on the show surface... If all your weights are on the inside, you only have a static balance, and with big tires, that alone could be enough to cause issues at higher speeds, especially on the front of an IFS vehicle.

Front alignment or looseness can sometimes cause a "shuffle" that becomes more noticible as speed increases. Doesn't necessarily feed back to the steering wheel, but also feels more like left/right movement than up/down. It doesn't sound like that is what you are describing... Bilstein shocks might actually make an imbalance feel worse, as they tend to have stiff low speed damping for good handling, which would transfer tire bounce right to the chassis.

When a few tires get out of balance or round, they will sometimes be out of phase, and so the shaking isn't that bad. When they line up their out of round or imbalance, it can really make the truck shake! When this is the case, you'll notice that the shake or bounce changes as you negotiate longer curves in the highway. This is because the outside tire turns ever so slightly faster than the inside tire, and that turns the tires relative to each other and changes the phasing, and therefore the magintude of an imbalance issue.

Good luck!