Road Vibration in DK45C

[tallur4me]

Just took delivery on a new DK45C and noticed that there is a lot of vibration at 1800 rpm or rpm's above 1800, when on asphalt surface. I called the dealer and he said to check the front tire pressure. Will do that sometime today. The vibration goes away at a lower rpm. The vibration is comparable to a separated tire on a vehicle and seems to come from the front section of the tractor.
This is my first cab tractor; however I have owned several tractors and have never had this type of vibration at any speed or in any gear. Any ideas?

[justforme]

is that in fourth gear high range and only at that speed?

if so i'd suspect a tire.

[virgil]

ag tires will ride rougher than industrial. could the lugs on the tires be creating the vibratation? That is if you have ag tires and if they are "puffed up" pretty hard.

[bigtractor]

Yes they will vibrate cause of tires.

Also make sure you are in 2 wheel drive on hard surfaces.

[slowzuki]

In our big international, the 4wd tires on front cause the cab ti hit a harmonic at about half throttle in 4th. You can go faster or slow down to get rid of it.

The whole cab acts like it is gonna rip off for this spell. Luckily it hasn't in the 8000 hrs or so the tractor has on it, the only thing is a chip or crack in the glass rapidly progresses when shaken like this!

[tallur4me]

Thanks for the reply's. The tractor is equiped with Industrial tires. I checked the air pressure and they are within limits. 32psi in front and 15 psi rear. Both the front and rear tires are loaded. I haven't had a chance to take in on the hard road surface today. Yes the vibration starts at 1800 rpm and continues almost uninterrupted up to the red line. 4th gear high side and in two wheel.

[KiotiJohn]

If you have a FEL, lift up the front to make sure you're really not in 4WD. If this does not fix the problem, check the measurements on the pivot on the front. In your owner's manual, you should have instructions for adjusting the pivot (toe in). That's where the front tires are not the same measurement from the middle of the tread in front and the middle of the tread in back. The fronts should be about 2-8mm less than the rear distance. If this is off, you'll get vibration. It's possible it was not properly set at the factory.
I hope this solves your problem. John

[bncsauve]

Just a guess, but, I would think with loaded tires, there would be tire speeds that would be unstable due to the movement or non movement of the tire loading material. Above and below those speeds would feel different.

[sweettractors]

Could it be that the tractor has set a while at the dealer over winter and has made the tires "out of round"? We run into that once and a while and usually it goes away with use on a regular basis--Ken Sweet

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[KiotiJohn]

</font><font color="blue" class="small">( Could it be that the tractor has set a while at the dealer over winter and has made the tires "out of round"? )</font>
You make a great point Ken. These bias ply tires are noted for this characteristic, but I didn't even think about it. John