Tires How Round Are Your Wheels and Tires?

[GregJ]

Just recently I had to travel on the road to get to our other lot to do some clearing. I traveled about 2 miles on the County road at close to full speed. After a while I started to notice a very rhythmic bounce and specifically from side to side. (I guess this is another Bouncy Bouncy post) At first I thought is was the road, then, with a sick feeling in my stomach, realized it was the tractor. I immediately went with "BENT AXLE" and dreaded the trip home to find out. I just checked it out and the axles are perfect...Whew....but both of my wheels have close to 1/2" side to side wobble and the tires are equally out of round. I realize that my tractor is engineered for a whopping top speed of 9 MPH, so tolerances can be slackened up a bit, but I was just curious if others have the same situation. The only time I can feel this is when I am going full speed on hard pavement.

Greg

 

[Junkman]

assuming that the wheels themselves aren't bent, then it would be in the tires. Since they are produced for off road use, I don't think that the manufacturers are very concerned about run out. Check the wheels and make sure that they aren't the culprit and then learn to live with it if it is the tires.

 

[GregJ]

Junkman,
My wheels have almost a 1/2" wobble to them. I don't know if they are bent or if this is within specs. My tires are out of round as well. I was just wondering if other tractors had similar characteristics. I can live with it no problem. Like I said, I can only feel it going full speed on hard pavement.

Greg

 

[Junkman]

1/2' out of round on the wheels would not be acceptable. Depending on how old the tractor is, you might be able to get the manufacturer to warranty them. If they are that bad now, they aren't going to get any better and if you have a loader on the tractor, it might just get worse.

 

[chim]

My right rear was VERY much out of whack. I followed #3 Son one day when he was driving it, and it looked like it had about two inches of wobble. When I checked it out, the problem was a loose wheel. It was loose where the hub fastens to the axle. I removed the bolts and wedges that grab the hex axle, and used a disc sander to remove a small amount of the material from the rounded parts of the wedges. Then I greased the parts and reinstalled them.

The wedges are made so close to the ID of the holes they reside in that they can bind and get tight in the hole rather than clamp the axle.

There was a thread on this where the poster referred to the noise a loose axle makes as "errnt, errnt, errnt". If you hear that noise, it's a giveaway.....................chim

 

[GregJ]

Chim,
Thanks for the suggestion. I haven't removed the hub assembly and cleaned it for a while. I have torqued both the wheel the hub fairly regularly, but it may be time to remove it and clean it well. I did have the squeaky wheel and posted here for help about a year ago. The wobble in the wheel could be caused by the hub. I'll check that.

Thanks,
Greg

 

[chim]

That's what the problem was with mine. After doing the maintenance above, the wheel ran true again. I spoke with the one mechanic when I was at the dealer's for supplies, asking him if it would be possible that the wedges were so long they butted together instead of getting tight on the axle. He assured me they couldn't do that, and looking at the marks they made on the axle confirmed it. He said he has done the same thing I did, plus removed paint from the axle where the wedges contact.

Wish I remembered who it was that came up with the "errnt, errnt, errnt". That was the perfect reference.............chim

 

[GregJ]

</font><font color="blue" class="small">( Wish I remembered who it was that came up with the "errnt, errnt, errnt". )</font>
That was B7500. I think in the last year there have been about 5 posts on this topic, but that was the most descriptive. I'll let you know if cleaning and retorqing the hub fixes it. I just torqued the bolts a few weeks ago, but there could be some dirt that got in there causing the shims to jam.

Greg

 

[frank_f15]

Greg: something is not right. i scoot down the road on ocassion at top speed(whatever that is for a b2400) with no wobble whatsoever. i would check what Chim suggested.

 

[markct]

well for what its worth, my ford 8000 bounces considerably on the road at about 16 mph or so, go a bit slower or a bit faster and its not as noticable, its just something about how it rides with the radials on it. the tires appear to run pretty true if ya watch them out the window of the cab, so i think its just something about the weight and speed of the tractor, its considerably less when i have a heavy implement on the back too. so this stuff may not realate to your tractor since an 8000 is in a different class, but still tires are tires so maybe its just the nature of it, not the outa roundness so much.

 

[billfires]

GregJ, one problem I had was uneven tire pressures. It mimics the problem you described. Just a thought. Bill C

 

[GregJ]

Thanks Bill,
That's something that I haven't checked in a while. I am hoping to rip into this problem real soon... However my wife seems to think that remodeling our bedroom has priority over my tractor right now..... I just don't understand women sometimes. So, it might be a week or so before I can tackle this project.

Greg

 

[GregJ]

I snuck out this evening and pulled a wheel and hub. I verified that the axle was true. Then I cleaned up the hub and shims and reinstalled it on the axle. That is when I could see what was happening. When I snugged up the bolt on the shims, it pulls the hub to the side of the shims, maybe about 1/32". This, in turn, magnifies as it goes away from the center of the axle. I loosened the bolt to check the amount of play between the hub and axle. There is some, but it didn't seem to be too much. There has to be some play in order to slide the hub on and off. Although, there is the possibility that the hub is worn from when the tractor was new and the hub loosened in the first 2 months. I was one of the pre "Ernt,Ernt,Ernt" posters. It was really loose. I'll give my dealer a call and see what he says the tolerance should be on that hub.

Thanks for all the posts.

Greg

 

[GregJ]

I had a nice talk with my dealer today and he assured me that my situation was not a major problem. In some cases where there has been significant wear on the axle, it is possible to use some shim stock to straighten out the hub. Axle replacement is not a huge job either. He did bring up a good point. I have loaded rear tires and that will increase any bouncing at full speed on a hard road. So.... I guess the lesson here is to keep your hub bolts tight.

Greg

 

[chim]

Greg, the "errnt, errnt, errnt" problem will force you to do an involuntary hula dance while seated. Slop in the plane that makes the wheel wobble is magnified as you move away from the hub. If you're bouncing up/down, tightening the hub won't do much.

I wouldn't worry about the axle being 1/16" off center when tight. That only makes the tractor travel up and down inside a range of 1/8". The tires aren't perfect, and road is likely "unlevel" by much more than that over the distance it takes to complete a rear tire rotation.

Does your B7500 have R4's? Mine does, and when it was delivered the tire pressure was way higher than I needed. I tried pressures as low as 7PSI to see what would work. At 10-12PSI I haven't had any trouble, but at 7PSI I managed to spin a rim inside the one rear tire when the rotary cutter got caught on something and the tractor wanted to keep movin' on. Rear tires on mine are loaded w/ antifreeze.

Good luck and let us know how you make out...............chim

 

[GregJ]

Chim,
My tires are loaded with windshield washer fluid. I have to keep them at 30lbs. I spun a rim at 20lbs., so I keep them firm. Actually, this issue is sounding like it is a bigger deal than it really is. I do only have a small fluctuation in "wheel wobble", and I think the dealer hit it when he said the fluid can magnify the side to side wobble on hard surfaces at higher speeds. Quite honestly, after removing the hub, cleaning and retorquing, I'm not too worried about it. There might be a small amount of wear on my axle, but definitely not worth doing anything about. The important thing is that I have learned something out of this process. It once again reinforces the importance of torquing those hub bolts on a regular basis. When I see a potential problem, I look at it as an opportunity to learn more about my tractor. Someday I may understand it.

Thanks,
Greg