Steering "Relay Rod" or Drag Link length and Pitman Arm Question.

[wyomingben]

When the front wheels are pointed straight ahead should the pitman arm be pointing straight ahead also and what is the set up length of the relay arm and how is it measured, center to center of the studs? '83 US FJ60 The reason I ask is that I have my alignment set up pretty well now but have a very, very slight pull to the right, I'm wondering if the steering box is trying to center itself.

 

[ntsqd]

Where do the tires point with the steering box centered?

I would venture that you can't rotate the pitman arm on the shaft, so your only option is to change the length of the drag link, assuming that is easily done.

 

[2mbb]

from the FSM

 

[wyomingben]

Ok, thanks for that. Is there a "center" or neutral for the steering box/pitman arm? My 60 was bought with a reman steering box and I'm wondering if the pitman arm was installed on to the steering box correctly, could it be clocked incorrectly? Maybe I don't understand, but with the engine running and the pitman arm not connected would the steering box center itself?

 

[2mbb]

There should be match marks on the pitman arm and the sector shaft for proper alignment of the pitman arm on the gear box. Other than that, the relay rod is attached. You can adjust the length of the relay rod to "center" the steering wheel, but I don't think a new-condition gear box has a center or neutral per se. My impression is that the tendancy of the front wheels to return to "center" is a function of the front wheel alignment, not the gear box.

 

[djawahir]

There is a 'center' for the steering box. What you can do is, turn the pitman arm all the way to one side. Mark where it stops. Turn the pitman arm all the way to the other side and mark where it stops. Halfway between the two points is the center of the pitman arm.

If it helps, my pitman arm is practically pointing straight ahead when my wheels are straight.

 

[lehiguy]

I'll pretty much put a ditto on what's been said already. Return to center is from the wheels, not the box, and your arm, as long as it is istalled correctly on the sector shaft, should point straight ahead. You can check it by doing what has already been said, turn to the extremes and find the center, should be straight ahead. Then use the drag ling adjustment to get the wheels pointing straight ahead as a pair. If your steering wheel is off after this exercise, then remove it and recenter that as it can go on in any position.

 

[wyomingben]

Perfect, thanks for the info.

Speaking of "centering it's self" being a function of the wheels, does "toe in" do this? If driving on a perfect flat road and your rig does not steer back to center on it's own could this mean you need more "toe in"? I know there are a lot of things that could effect this like tire air pressure, wind, weight and balance etc, I'm just asking if all else was perfect.

 

[lehiguy]

Perfect, thanks for the info.

Speaking of "centering it's self" being a function of the wheels, does "toe in" do this? If driving on a perfect flat road and your rig does not steer back to center on it's own could this mean you need more "toe in"? I know there are a lot of things that could effect this like tire air pressure, wind, wieght and balance etc, I'm just asking if all else was perfect.

No, toe is the difference between the wheels being set dead straight ahead vs. pionting slightly apart or together. A small degree of toe in is usually what you want. Caster (adjustable with shims) and caster (not really adjustable) contribute the most the the return to center feeling. Basicly, the wheel on the outside of your turn creates more resistance and therefore tends to want to get pushed back to being inline with the other wheel.

 

[overhanger]

mbb,
Where did you get the scan you show? 1990 FSMs show a different and incorrect length of 960mm. I found the 1001mm length in a 1984 Heavy Duty FSM and it is correct.

 

[wyomingben]

The reason I asked is that my 1980 FSM showed two different lengths, both were much shorter then my measurement. My FSM covers all models, 1001 mm sounds more correct or closer to what I have. I believe that to be accurate but I will have to measure it again.

 

[wyomingben]

Mine is as close as I can tell 997 mm + or -. So 1001 mm is correct. The center of the hole on the pitman arm that attaches to the relay arm is not inline with the marks on the selector shaft. The marks on the pitman shaft are under the nut, I'm going to pull it just to see unless some one has a pitman arm handy and can confirm that the marks and center of the outer hole are not supposed to line up.

 

[2mbb]

mbb,
Where did you get the scan you show? 1990 FSMs show a different and incorrect length of 960mm. I found the 1001mm length in a 1984 Heavy Duty FSM and it is correct.

It's from the scanned version of the 1984-1990 Body & Chassis FSM publication number 36262E. You can download it from here: Master Portal - forums.bauchan.org/Downloads - page: 1

 

[wyomingben]

My pitman arm was a couple of teeth off from being lined up with the marks, I reset it and set the relay arm to exactly 1001 mm this threw my steering wheel off almost 180 degrees, so I reset it also. Can't say any of this made any difference but at least I know it's correct. I put a ratchet strap through the u-joint next to the steering box and measured the play from the u-joint to the steering wheel, that was about a 1/4 inch. with the strap off I had about 1" 1/4" play at the wheel. I turned the steering box ajustment screw in 1/2 turn. Rechecked it after a drive and now I have less then an inch of free play in the wheel. I now have new knuckle bearings, TRE's, "do it's your self" alignment and it steers and tracks way better. Thanks for all the help.

 

[oldwineo]

Make sure your tires have the same pressure in them and the wheel berings are not loose. Tire pressure will cause more pulling than anything outside of a sheered center pin.

Make sure there is no crown in the road.

 

[MTN.GOAT]

Castor

I just perused this string and did not read it entirely but if I get the question (slight pull to the right) . Two ea. front axle housings that I have worked with when doing a spring over and doing the cut and turn I found the passenger side to be one degree off from the other side, I have heard may opinions on why this may be the case but if this is a consistent case for 60 axle housings this will cause a slight pull to the right. Some folks purposely add an extra degree to the passenger side to compensate for the crown in the road. Not sure about all the facts, I'm just running on the difference I saw with the two axle housings I have worked with and alignment folks and their knowledge on castor angles.