International 300 steering geometry problems...

/ International 300 steering geometry problems... #1  

LD1

Epic Contributor
Joined
Apr 30, 2008
Messages
22,822
Location
Central Ohio
Tractor
Kubota MX5100
Well, I have been trying for the last day and a half to get this steering dial in an maybe I am just over thinking it or overlooking something simple....hopefully, someone can help out that is familiar with the manual steering on these tractors.

Those that are familiar, there is a mechanical stop on the spindle "knuckle" itself that limits how far the spindle can rotate. It allows a certain amount of travel and no more.

The pitman arms on the steering gearbox can only move so far also.

Well...these numbers are exactally the same when measured. No issues if the front axle is level. But when the front axle tries to pivot:
On the side coming up, the distance is getting shorter between the spindle knuckle and the gearbox pitman arm.
On the side going down, the distance is getting longer.

The issue is the knuckes on the spindle are against the stop. This causes a bind. Not sure how I can adjust anything to make the issue go away. Cause the gearbox and spindle travel is the same. But nothing to account for the front axle pivoting and changing things.

So just wondering if this is the way it is supposed to be?? And when the axle pivots, it just feeds back through the steerng colum??

I have also had the steering gearbox appart. Which leads me to my next question...

The left hand shaft, that has the nub driven off the worm gear, has 3 teeth. The right side has 4 teeth. So common logic, I put the center tooth of the 3 gears in the middle of the 4 teeth of the right. But that puts the alignment mark way off on the pitman arm. Thats not a huge issue as I can jump a few splines to compensate, but the way I took it appart, the gears werent centered. The middle tooth of the 3 gears was between the first and second gear on the 4-tooth shaft. Just didnt seem right. And would also cause a lot of slop when the right side pitman arm was at its furthest forward position.

I dont think thats the issue though. cause I can (and did) re-position the pitman arm to compensate. Hopefully someone has some knowledge of these gearboxes. Not sure what else to do.

And if anyone has a 300u with manual steering, One thing I would like to see is a shot of the left and right side pitman arms, with the wheels pointed straight ahead.:thumbsup:
 
/ International 300 steering geometry problems...
  • Thread Starter
#2  
No one has any ideas??

I subscribed to Red Power Magazine forum, but waiting on an administrator to approve me so I can post:mur:
 
/ International 300 steering geometry problems... #3  
I don't have any pics of the steering on my 300U. I am thinking that you have the arms reversed or something, for them to be binding.
 
/ International 300 steering geometry problems... #4  
Does your manual show the steering, like where to lube it?
 
/ International 300 steering geometry problems... #5  
I have no idea about the geometry or inner workings, but I've got an idea about something....

You say that when the axle pivots, one side shortens up and the other side lengthens. You say that since the pitman arm is against the stop, this sorta creates a bind condition. Reading between the lines I'm assuming that since the pitman arm is against a stop you must have the steering turned full to one side or the other, right? But still, I don't see how that creates a bind unless the turning angle of the wheels themselves is prevented from moving. In other words, as the axle pivots and one side shortens while the other side lengthens, the length changes should result in slightly changes steering angles at the wheels, right?

So if I understand correctly, you've just got what is commonly referred to as "bump steer." That's when change of height of the wheel relative to the chassis results in some steering change due to the geometry. It's very difficult to completely eliminate bump steer in a suspension design. Good race car designers attempt to create geometry that takes advantage of what cannot be eliminated; they try to get a good predictable, linear curve of bump steer such that the outside wheel in a turn is progressively steered straighter as the wheel is compressed up into the fender. This is conducive to smooth control if dialed in well. But honestly it isn't much worth considering with the usage profile of a tractor.

If I've misunderstood I apologize.

xtn
 
/ International 300 steering geometry problems...
  • Thread Starter
#6  
I don't have any pics of the steering on my 300U. I am thinking that you have the arms reversed or something, for them to be binding.

Does your manual show the steering, like where to lube it?

MAnual does show all the setups and how to align all the marks to put steering at center, and then adjust toe accordingly. Things arent binding because of lack of lube, they are binding because its against the stops.
 
/ International 300 steering geometry problems...
  • Thread Starter
#7  
XTN, bump steer is a good analogy.

Picture this....Front axle pivots. Lets say the right tire drops in a hole and the left comes up, The right tire going down is getting "farther" away from the steering gearbox. Well since the tierod is a fixed lenght, it "pulls" or causes the wheel/spindle to turn in toward the tractor.

The side coming up, the distance gets shorter, causing the tierod to "push" the wheel outward.

So in this case, with right tire (as viewed from the seat) drops into a hole, it will cause a bump steer to the left. No problem.

BUT, lets say the wheel is turned all of the way to the left already. Both spindles are against a mechanical stop. So as the right tire tries drops into a hole, the distance is lengthend, and the tierod tries to pull back on the spindle arm, but cant cause its against the stop.

Same thing on the left side trying to raise up, but cannot because it causes the tierod to try to push against the stop. Therefore, the only way the axle can have full pivot range, is for the steering wheel to be about 1/2 turn away from the end of its range...

OR, in other words, if the steering is turned hard left, and you hit some uneven ground, either something is going to break/bend, or the steeringwheel will be jerked 1/2 turn out of your hands....
 
/ International 300 steering geometry problems...
  • Thread Starter
#8  
pics may help.

This is the left spindle as viewed from the tractor:

Here, the wheel is turned hard left and the axle is level. You can see I am against the stop. So....the axle cannot raise up on this side if it needs to, unless the tierod pushes back against the steering box.
IMG_20131105_094559_115.jpg


Here the wheel is turned hard right. Again, axle level and against the stop. So The axle can cannot drop into a hole if needed without trying to pull on the steering box.

IMG_20131105_094624_446.jpg

Same deal on the other side. In that first pic, the axle cannot raise if needed, but is free to drop all it wants, but the right wheel would prevent that. In the second pic, the axle is free to raise if needed, but again, the right side is into the other stop.

So...when turned hard one way or another, one side is preventing the axle from pivoting one way, the other side prevents pivoting the opposite direction.

Its like the gearbox has too much travel. I dont think it should be able to go from stop to stop when level. Otherwise it has no room to compensate when pivoting.

And with the adjustable axle, the farther out the axles are extended, the worse it is.
 
/ International 300 steering geometry problems...
  • Thread Starter
#9  
I may have stumbled on a possible cause, but info is sketchy at best.

I found an old thread on Ytmag that mentioned something about the 300u getting longer pitman arms somewhere around serial # 26000, as well as longer front spindle arms.

I am wondering if I possible have the longer pitman arms, and shorter front spindle arms causing the issue??

Anyone with a 350U or similar model be able to measure the lengths of their pitman and spindle arms??
 
/ International 300 steering geometry problems...
  • Thread Starter
#11  
Well, I think I am going to shorten the pitman arms unless someone speaks up in the next 15 minutes or so.

From what I could find, The short ones are supposed to be 8-7/16" and they went to the 11" ones @ serial 26000 something, but they also made the spindle linkage (arm) longer as well.

This might explain why it seems my gearbox has TOO much travel and am hitting the stops on the axles too soon.

I did some mock ups by holding the draglink about 2" higher up on the pitman arm (to give the draglink less overall travel), and I think this is indeed my issue. At somepoint, it hink someone changed the steering gearbox or at least the pitman arms. Cause my tractor is serial 13000 something.
 
/ International 300 steering geometry problems... #12  
I got it now. Seems to me that you need either longer spindle arms, or a shorter pitman arm.

Alternate solution: Either grind down the stops at the spindles, or fab some stops for the pitman arm that prevent the spindles from getting all the way to their stops. When the tractor is up in the air you ought to be able to test both left and right steering maximums along with full axle pivot each way to determine the max amount of steering input available without triggering this condition. But I can think of a possible negative going with such an alternate solution: Full steering input while driving and then one or both tires hit a curb or log or whatever, and since the spindle's themselves aren't at full stop, they still have room to turn more. But since your pitman arm is stopped, it's going to stress the tie rods, drag link and joints.

So best to get the ratio of pitman arm to spindle arms correct. If you go TOO short on the pitman arm, you could have the same problem as outlined above with my "alternate solution." Is it a cast iron piece, or is it some flat stock that you could just drill a new hole in?

Does it have idler arm(s) as a similar setup in a car would have? If you change the length of the pitman arm would you have to change the idler arm(s) to match?

xtn
 
/ International 300 steering geometry problems... #13  
Sorry I was typing that before I realized you had posted again. I think you're on the right track. I suggest leaving the condition slightly, such that it could jerk the steering wheel an inch (but not half a turn!). If you go past eliminating the condition entirely, then you have the problem condition I outlined previously: Force at the tires could really stress the links/rods/joints.

xtn
 
/ International 300 steering geometry problems...
  • Thread Starter
#14  
ITs a cast piece. Not sure if cast iron or cast steel til I put a grinder to it.

I called bates corp in indiana. He is gonna do some checking, but here is what I found out so far....

The pitman arms are the longer ones that are 11", that werent supposed to be used on the 300 until AFTER serial 26xxx, OR if it had power steering. They were however used on the 350.

The spindle arms are ALSO the longer ones, that again, were only supposed to be used in conjunction with the 11" pitman arms on the PS models, 350's, or after serial 26xxx.

So....I was hoping it was as simple as having short arms up front and long ones on the steeringbox, but that isnt the case. So I dont know why this isnt working??? These arms are supposed to work together.

I have also come to the conclusion that the steering box is from a 350. When I had it appart, There were 3 teeth on the sector shaft that is driven by the worm (the one that drives the left tire), and 4 teeth on the right side shaft.

According to IH parts diagram, the 300 box had 4 teeth on the driven shaft, and the 350 had 3 like I have.

I thought about grinding the stops, to alleviate the bind, the the wheels already turn far enough. almost too far IMO. I am gonna wait (I think) til bates calls back and see what they say, but I think my solution to shorten the pitman arms is likely what I am gonna do.

I wish I knew someone that had a 300u or 350u that I could look at first hand though...
 
/ International 300 steering geometry problems... #15  
Did you post on the farmall board on ytmag? Those folks know IH, I think it gets a lot more traffic than redpower, and some guys post in both places. I looked at the jackson power steering for mine, but I didn't want to spend that much. With a loader on it, it would pick up 3K!! But you couldn't turn for sxxxt. I did break one of those spindles off, and bought replacements.
 
/ International 300 steering geometry problems...
  • Thread Starter
#16  
Do you have any old pics of yours from the side? Its easy to see if it has short or long pitmans.

And do you remember the length of the spindle arm you got
 
/ International 300 steering geometry problems... #17  
I broke the spindle itself. These old girls weren't really designed for loaders, especially heavy modern ones. It will handle like a sports car with no loader and a bushhog on the back. Without ps, a loader on it is useless. I don't have any pics, I got rid of the ute about 4 years ago. I will call about and find the guys name, he was going to part it out, he is a jockey, he really wanted it for the loader and tires.
 
/ International 300 steering geometry problems...
  • Thread Starter
#18  
Well, I may just call it a day. I dont want to cut up the pitman arms jsut yet. I did post on ytmag, and still havent been approved by a moderator to post on red power yet:mur"


I dont know if it is something as stupid as me overthinking it. And with it out in the field and weight on the axles/tires, things would be well???

But it just dont seem right sitting on the jackstand in the shop. When turning right for example, the left tierod is pulling back and the right one is pushing. Once the stops are hit, you can keep turning the wheel and it forces the right side (the one pushing) to push the axle down, and the left tierod to pull the axle up.

So when turning hard right, near the end of steering travel, the right tire is pushed down and left pulled up til there is almost no pivot of the axle left. And vice versa when turning right. It binds everything up.

Now I knoe in the field, this wouldnt happen, cause you cant turn the steering wheel hard enough to make the axle pivot. But it worries me that you can turn it far enough to hit the stops and then what happens if it does try to pivot???? Either break something or jerk the wheel out of your hand??
 
/ International 300 steering geometry problems... #19  
All these old girls will jerk the wheel around. Some folks have had fingers broken, especially with spinner knobs hitting them.

Btw, "call it a day", you have been doing enough to make me tired!!! :)
 
/ International 300 steering geometry problems...
  • Thread Starter
#20  
HAvent really got much done today actually. Except trying to figure out this steering, which isnt very productive.

I was gonna start re-assembling some of the hydraulics, But I am out of -115 o-rings in my kit, so that went on hold.

Ordered a new kit, I was getting low on o-rings anyway. $15 for 400+ pieces. I need 9 -115 rings, and there are 13 in the kit:thumbsup:
 
 
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