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Significant shake at 60mph+/-. I need some advice and knowledge


Rotorhead
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Hello All,

Well I finally found a rig I like for my future needs. A 2010 Volvo 780. Of course needs some TLC but hey, it's used. Anyway when I was driving it home from out of state I noticed two things. 1. it sounds like a Sherman tank, is that what they sound like normally from the inside while on the road? 2. and more importantly it has a pretty significant shake at 60mph. Nothing really in the steering wheel, it just shakes. So I am seeking any ideas from all who have the experience. What could it be? The sound is kinda like a drum roll. Tires look like they are wearing evenly. It has brand new brakes on the front. 

Once I get this shake resolve It will be pretty darn nice.

 

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6 hours ago, Star Dreamer said:

Could be one of these or multiple of them or other stuff.

Tires out of balance, bent drums, wrong drive line angle, driveshaft out of balance, bad u joints, Etc...

 These are where I would start.

 I had a beautiful Freightliner fld120 that when I bought it, had a shake that started about 50 mph. The prior owners put all new virgin tires on it to try to stop it. No luck. They put all new brake shoes and drums on, no luck. They rotated the front tires on the wheels 180, no luck. New shocks etc., etc., etc. No luck. So they gave up and sold the truck to me. I bought a pair of those bead balancer tubes that go between the wheel and brake drum. No luck.

 I put a gopro on the frame up front and went for a drive. No shaking from the front axle. Put it on the rear frame, no shaking. Prior owners had the local drive line shop check the u-joints and drive line trans to axle, and interaxle  etc.

 By pure luck I happened to catch up with crusty old log truck mechanic and told him what was going on and what was done to solve it. He shook is head and said drive shaft slip yoke. I told him the truck was at a drive line service shop and they said nothing was wrong with the drivelines. Did'nt care. Said slip yoke period. Go talk to Ken at 6 states in Portland he said.

 Ok. So I called Ken and he agreed. Said just bring the whole drive line in and he will show me why. I did, he did. New slip yokes and splines for the main and interaxle, a couple hunnerd bucks, problem solved.

 My truck had a manual 10 speed so I could also "feel" the shake in my hand when at speed. Once I got the slip joints replaced, smooth as glass as they say.

 

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All good suggestions about the drivelines, ujoints and splines.  One other quick and easy check is to check and see if the driveline is in time.  This means, are the ujoints lined up.  If the truck was towed and the driveline pulled, what they do is un bolt the ujoint at the diff and pull it out of the splines at the slip joint.  When it is reinstalled it could have been one spline off and it will cause a vibration.  Look to see if the ujoints are lined up to each other.  

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5 minutes ago, dennisvr said:

All good suggestions about the drivelines, ujoints and splines.  One other quick and easy check is to check and see if the driveline is in time.  This means, are the ujoints lined up.  If the truck was towed and the driveline pulled, what they do is un bolt the ujoint at the diff and pull it out of the splines at the slip joint.  When it is reinstalled it could have been one spline off and it will cause a vibration.  Look to see if the ujoints are lined up to each other.  

 Big thumbs up. Phase is crucial.

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My 780 had a bad vibration at 50mph plus, had complete front end rebuild(kingpins, bearings and a new carrier bearing, front steer tires balanced good and had retread super singles on rear. went to have them balanced and only did 2 tires on passenger side before throwing in the towel on them.   one tire was 43 ounces and the other was 36 ounces (ouch) so i replaced the 4 supers with virgin tires and all the vibration is GONE, smooth sailing all the way to 85mph plus on the truck. Moma loves the ride now.    hope you find the problem and enjoy the truck.

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I'm in the check the driveline U joint alignment and splines camp. 

A mismounted tire will cause a "470 rpm" out of balance - the tire is running out of round in the vertical plane. A tire shop will dismount the tire and turn the wheel inside the tire and remount it and check the balance.

But check the drivelines as mentioned by others....

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51 minutes ago, noteven said:

I'm in the check the driveline U joint alignment and splines camp. 

A mismounted tire will cause a "470 rpm" out of balance - the tire is running out of round in the vertical plane. A tire shop will dismount the tire and turn the wheel inside the tire and remount it and check the balance.

But check the drivelines as mentioned by others....

I agree, all tires have a small ridge near the bead, that is to assist the tire guy to center the tire on the rim. If the small bead is not concentric with the rim the tire is not mounted properly and cannot be accurately balanced. Years ago this mis-mounted tire would be "trued" by shaving off the high-point of tread, then tire engineers developed that small ridge to assist with proper tire mounting.

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Thanks for all the information. As I was afraid there could be numerous paths to explore. It just needs a good cleaning and the vibration gone and it will be good to go. A little TLC along the way of course.

I will be checking the drive shaft/u-joints tomorrow.

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