Noticeable, regular "lurch" felt on smooth roads.

[RjCorazza]

My rears will get a flat spot after a couple of weeks sitting. Makes no difference if they're fluid filled or not.
I road my tractor a bit, and the tires smooth out after a couple of miles.

 

[Tinhack]

Could be as simple as a loose wheel. Check the lug nuts.

 

[zzvyb6]

You Picked a Fine Time to Leave Me Loose Wheel ....

 

[Torvy]

With four hungry cylinders and a crop in the field...

 

[Smokeydog]

Had a bad sounding “clunk” from left rear ever so often on 20 year old M5030 when grading the hillside driveway. Lug nuts tight. Everything looked okay from outside and was dreading maybe internal damage? Finally saw that some of disk to wheel rim bolts were loose. Two tightened okay, one needed a new bolt. Of the many ag tractors over the decades with adjustable wheels was the first one that gave that problem.

Any tractor, especially new tractors should have bolts checked for tightness periodically as per the manual.

 

[Erbid]

I had a diff-lock engaged. Made a nasty pop sound if the tires couldn't slip, like on asphalt. On some smaller tractors, if the brake pedal is down a bit, the diff-lock engages, even though the brake is not engaging.

 

[MHarryE]

Tractor tires aren’t made to highway service tires. The larger the tire, the more out of round allowed. In addition, flat spotting whether radial or bias. My guess is you have bias ply 17.5 x 24 tires. Not as much hop as the larger tires on my M series, 430R24 on my M5 and 680R38 on my M7. The M7 can get wicked at 31 mph with cold tires. I had a L6060until last year and it’s tire hop was not nearly as bad as the large ag tires but I did keep high pressure in the rears of the L6060 which reduced flat spotting when sitting around where my M7 tires are less than 10. The M7 is worst in our cold Minnesota temperatures where Rim Guard ballast gets very viscous and the air spot can actually rotate creating a huge imbalance so I can be limited to about 10 mph until the Rim Guard loosens up.

 

[SDT]

Had a bad sounding “clunk” from left rear ever so often on 20 year old M5030 when grading the hillside driveway. Lug nuts tight. Everything looked okay from outside and was dreading maybe internal damage? Finally saw that some of disk to wheel rim bolts were loose. Two tightened okay, one needed a new bolt. Of the many ag tractors over the decades with adjustable wheels was the first one that gave that problem.

Any tractor, especially new tractors should have bolts checked for tightness periodically as per the manual.

Agreed.

Re-torquing wheel and rim bolts is part of PDI procedure for most manufacturers but few dealers do it. Those that do simply run over bolts with a large impact wrench rendering it very difficult to loosen nuts in the future.

Neighbor needed to buy new wheel center for Mahindra due to loose lug nuts discovered after warranty had expired.

 

[dodge man]

Do you have fluid in your rear tires? I’ve had that thump around before but usually when it’s cold and using Rim Guard.

 

[MH8675309]

If the tires are filled that can account for some movement at high speeds