Tractor front end geometry???

CTyler · May 18, 2004

The axle is solid and no suspension so the camber stays the same with the bucket empty or full.

I don't notice it dragging a box blade, doing loader work in an area or going thru the woods but then your only going a few mph. Driving down the road is at 12-15-17 mph is an experiance that you work up to. Even driving up and down the driveway 650' to take out the trash at 6-7 mph it wonders. Its better carrying a bucket full of dirt or rock but then I'm going 4mph. You get used to it but why should you have to? Maybe the hydrostatic steering makes it worse. I just keep thinking there has to be a better way.

Robert_in_NY · May 18, 2004

The wheels are set up that way for steering. It allows the tractors front 2wd wheels to get a good bite (with tri-ribs that is). Tractors were designed to be used in the field. If you had a lot of linkage parts do you realize the amount of work needed to keep the front end running smooth, let alone if you run into a post or tree with a tire (how much money would it cost to repair?). The front axels were designed for simple adjustments and good bite for steering. Now, for sub-compacts it is a different story as they are used mostly for home maintenance. Larger compacts do serve some times in the field. Oh yeah, it cost a lot less to design and produce also meaning more money in the bosses pockets.

As for the amount of play, I have never noticed it while doing field work or tight work around and in the machinery shop. Either you are just too use to your cars steering or you have a problem with your machine.

JerryG · May 18, 2004

CTyler,
I would bet that your toe-in is set wrong. If it is off, it will wonder all over the place. Hydrostatic steering shouldn't cause a problem.

California · May 19, 2004

( Sounds like your tractor needs some frontend work. My 25 year old Yanmar doesn't have
loose/sloppy steering. -Norm )

I was just about to post the same reply. At 1050 hours and 24 years, I don't think my Yanmar's steering is any different from new.

KiotiJohn · May 19, 2004

Ctyler, have you measured your toe in and adjusted it to factory specs? Sounds to me as though you either have incorrect toe in, or you have worn parts as my tractor does not suffer this problem. John

CTyler · May 19, 2004

I haven't checked the tow-in, its easy to spot that it has it though. Hopefully nothing is worn, it only has ~440 hours on it. The tie rods ends are tight, haven't looked anywhere else.

....One thing I have noticed is that the wheels need to be cranked to one side and/or the other before driving it. Otherwise you have to keep turning the wheel slowly and continously going aroung a sweeping corner on my drive for example. And it hardly does anything for the first spin of the wheel after its been sitting.

jimb111 · May 19, 2004

Jim, I am a bit slow and not understanding your description for the Toe-In tool. Could you provide a sketch or more details.
Thanks

Robert_in_NY · May 19, 2004

Isn't your tractor hydraulicly steered? I know I do not have steering rod down my TN as it is all done by a cylinder on the front axel. Any play in it and yours could and most likely is from the lag in the hydraulic system. Just how tractors are.

slowzuki · May 19, 2004

Zero castor - with the no feedback hydrostatic steering, castor is useless, before power steering no castor made it possible to manually steer a huge tractor.

Toe-in - when steering can become sloppy, toe-in is the normal way of getting stable steering. Toe-out would cause the tractor to be yanking in every which direction.

Positive camber - look at the kinpin inclination and draw a line between the 2 kingspins. It should / may hit the ground in the centre of the tires contact patch. This reduces torque steer on a 4wd with manual steering and can be used to reduce loads on bearings in all types. I suspect the camber on the tire allows some comprimises in bearing design. As you get to larger tire sizes it is possible to get the correct geometry with the camber. Most 4wd ag tractors have minimal camber.

Now of course the popularity of R-4's in compacts and offset rims surely postdates the design of the castings and axles. We may see some different geometry in the years to come.

( I know tractors are not performance vehicle but why is the geometry so wacked? There is zero caster, lots of toe in and positive camber. The extra toe in is probably there to help it track better with the loose steering. Caster would help this as well. Its' kind of irritating that the tractor will not stay where you point it.
)

normde2001 · May 19, 2004

"And it hardly does anything for the first spin of the wheel after its been sitting."

Are you saying there is no positive mechanical steering box on your tractor? Hard to imagine that. I have less than 1" of free play in my steering wheel before the front wheels move.