Front wheel camber

[TCBoomer]

I've tried searching and came up with zilch.

Anyone know why the front wheel camber for TC series is set on the positive side?

My 21 looked odd with as much camber as it had. My new 24DA also is set on the positive side, but is not as noticeable...possibly due the tire size.

Could it be related to stability /forums/images/graemlins/confused.gif

 

[dass]

TC, I found the same thing on my 33. I checked it as per the manual ;width of front compared to rear of the front tires. They were off by 1 1/2 inches. I guess they don't check'm during assembly. Quality Control ?

 

[jinman]

David, it sounds to me like you are describing toe-in or toe-out rather than camber. Camber is when the top of the tire leans inward or outward. Negative camber (tire leans inward at top & outward at bottom) on cars is common to improve handling in corners. I can't think of an instance of positive camber unless it might be on road graders where the tires lean as the grader turns. TCBoomer, do you mean your front wheels are wider at the top than at the bottom?

I'd expect a slight toe-in on our tractors, but I don't know if 1-1/2 inches is normal. That sounds like a lot and would cause severe scuffing on the tires if driven on pavement. /forums/images/graemlins/confused.gif

 

[MNkurt]

I'm thinking that 1-1/2" isn't normal. Couldn't find anything in my TN55-TN75 manual, but peeked in my combine manual and found a toe-in tolerance of 7/16 to 19/32"(11 to 15mm). That's for 24" rims. Can't imagine it would be more for Boomer size tractors.

Looking forward to hearing the final verdict. Good luck.

Kurt

 

[MNkurt]

Just looked in my combine(CaseIH 1660) manual again and saw where 16" wheels toe in is 9/32 to 3/8"(7 to 10mm).

They also mention a power guide wheel toe in of 1/4 to 3/8"(6 to 10mm).

If you have MFWD, I'm thinking the power guide wheel adjustment is gotta be getting close?

I better quit throwing out numbers and hope someone who really knows replies! /forums/images/graemlins/confused.gif

 

[thcri]

MnKurt,

I am from Rochester, Mn. What city are you from if you care to say?

murph

 

[dass]

jinman, you're right , it's caster. You could look at the front of mine and the wheels were pointed in different directions. Easily corrected though. It's a simple quality control issue. No excuse for them to be that far out (1 1/2 in.) on a new tractor.

 

[MNkurt]

Hey Murph:

My address is Rothsay, a town of about 500, but an easier town to recognize is Fargo, ND. I'm 40 miles SE on the MN side.

 

[RickB]

Not caster either, it is toe in (or toe out). Should be in the range of 0 to 3/8" of toe-in for most compacts. Note this info does not come from any manual, but it is better to be in that range than outside it. Camber has been accurately described, caster is the relationship of the steering swivel axis to a vertical line. Of the three, toe in/out is the only adjustable value on tractors.

 

[rebelmedic]

Per Operators manual for TC48DA toe in range is 0-13/64

 

[dass]

I'l get it right sooner or later....anyway, I had the tractor about a month before I noticed it . The paint was worn off the threads on the right side of the tie rod.Thought that was a little strange on a new unit.

 

[thcri]

Oh I know where Rothsay is, in fact I have some friends in the area, well at least the kids where from that area. Does the name Dan Roen ring a bell. He past away a few years ago. Big auction a few months back on his farm. He was a collector of old machinery. If your from that area there is a pretty good chance you knew of him or even knew him.

Dan Roen


Lot of old time stuff. And I could not believe the money they got for that old stuff. Some of which I sat on or drove.


murph

 

[TCBoomer]

Yes wider at the top as in the top of the tire leans out.
I am quite experienced in wheel alignments since I've done hundreds if not a few thousand during my 27 yrs of being Mr Goodwrench /forums/images/graemlins/tongue.gif

It has been my experience that if the angle is noticeable by eye, then it's at least one full degree off 90* or in this case 0* since that's the center point for camber readings.

It's obviously a design feature since it's not adjustable by standard practices...then again, EVERYTHING is adjustable /forums/images/graemlins/grin.gif I've noticed it on both the NH class I & class II tractors. Not sure about the class III.

Well curosity got the best of me and I decided to try to measure it. I used my Stabila elec level and showed a positive reading of about 1.3*-1.4*. However this reading is not that precise, since I only read off the tire sidewall and not the wheel itself. But close enough to prove my point.
Hmmm...maybe I should trailer this rig down to work and set it up on the alignment rack /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif Bet I'd get my chops busted big time /forums/images/graemlins/tongue.gif /forums/images/graemlins/tongue.gif

 

[TCBoomer]

Rick

I've read many of your posts and know by your bio that you're a NH tech. Any chance you know why they set the camber that far off 0*? Caster...yes, but camber???

 

[jinman]

TCBoomer, here are the numbers for the Class III 2WD front end. I couldn't find any similar numbers for the 4WD front end or SuperSteer.

King Pin Inclination - 8°
Toe-in - 0 - 3/16"
Caster (fixed) - 0°
Camber (fixed) - 3° (I assume that's positive)

I guess I was wrong about the positive camber. It appears it is common on 2WD tractors at least. It's still a mystery to me why the Repair Manual did not list any similar angles for the 4WD tractor that I could find.

 

[TCBoomer]

Yes it would be positive and WOW, 3 degrees positive??? Hmmm...must be a valid reason for that and so far no one has an answer. My thinking is for directional stability, but maybe Rick or someone else will drop in and tell us.

As far as the mystery for listed specs for a 2WD versus 4WD, could it be that 2WD's are adjustable and 4WD's are not?

Bob

 

[jinman]

</font><font color="blue" class="small">( My thinking is for directional stability. . . )</font>

In cars, negative camber provides understeer and positive camber provides oversteer. Since you want a tractor to turn in a hurry (doing donuts is a good thing), oversteer would be the choice. I'm pretty sure that's the reason for the postive camber.

Did you notice that the specs said the camber and caster were "fixed" in my last post? Since tractors don't have any suspension, the camber and caster cannot be changed unless you bend the front axle. You might make a plate that could be inserted along the axle on a 2WD tractor, but a 4WD's rigid axle would make me believe it would be impossible to adjust by any reasonable means. ...and why would you really want to? /forums/images/graemlins/confused.gif

 

[TCBoomer]

<font color="blue">In cars, negative camber provides understeer and positive camber provides oversteer. Since you want a tractor to turn in a hurry (doing donuts is a good thing), oversteer would be the choice. I'm pretty sure that's the reason for the postive camber.

<font color="black">I agree, but by increasing the camber that much, the scrub radius would increase and that would accelerate tire wear. I guess that's the trade off for quicker/stable turns.

<font color="blue">Did you notice that the specs said the camber and caster were "fixed" in my last post?

<font color="black">Uh...no, not really /forums/images/graemlins/blush.gif
The 3* camber is what got my attention. I didn't expect to see a spec that far off center.

<font color="blue">...and why would you really want to?

<font color="black">I wouldn't even consider altering the intended design. I just though it was odd to set camber to that angle. When I bought my TC21 and noticed the angle, I asked the dealer. They didn't know for sure, but said it helped prevent rollovers while using the FEL. Now that I found TBN, I figured I could find the real reason.

One thing I'm still curious about is how long the tires last if the tractor is driven mostly on asphalt. My town is responsible for mowing along all the local roads...many, many miles! They use a class III NH and I wonder if tire wear is a problem, or is the tractor spec'd different? I'm fairly certain that it is 4WD.

 

[jinman]

</font><font color="blue" class="small">( One thing I'm still curious about is how long the tires last if the tractor is driven mostly on asphalt. My town is responsible for mowing along all the local roads...many, many miles! They use a class III NH and I wonder if tire wear is a problem, or is the tractor spec'd different? I'm fairly certain that it is 4WD. )</font>
John Ireland on Camber

I think almost any tractor driven on pavement will exhibit quick tire wear. Everything from the rubber compounds, cleat design, and tractor weight will add to the wear. My guess is that turf tires would probably last the longest because the increased amount of surface in contact with the road reduces the pressure felt at any single point. The ability of the tractors to turn on a dime would surely scuff off rubber in the process. Almost any time tractors drive up an embankment covered in concrete, you can see a black cleat trail. On soil, that wear would be almost none, but on concrete the tires scuff. I've seen a lot of industrial loader-backhoes with slick tires.

The link above is one specific to camber, but by doing a Google search for camber and caster you can find lots of good info. I read one article that explains the "black art" of setting the suspension on race cars. Interesting stuff! /forums/images/graemlins/cool.gif

 

[MikeBurr]

So that is why my fronts look like they have more wear than the rears. Asked the tech when he was here to do the first oil change why the fronts already had molding marks worn off(mainly the left tire) and the rears looked new. He checked the toe-in and said it was good. The tractor has not been on payment, only gravel or dirt, but the front tires still look a little worn. Maybe it will be like motorcycles, two or three front tire replacements to one rear replacement.