Pitman arm bushing

[Saff57]

I have a 2003 Alpine motor coach with the Shepard steering box. It has a little over an inch of free play in the steering wheel. I have new ball joints and bushings in the front end which has greatly decreased the wandering on the road. I was under the coach and I had my wife turning the wheel with the engine off. It appeared to me the pitman arm bushing seemed to move in a manner I don’t think it should. I’ll attach a video of the movement. Does anyone have a part number of that pitman arm bushing? I would greatly appreciate giving me an opinion on the video. Rv repair place wants to put a new steering box in it and doesn’t think the pitman bushing is bad

[Saff57]

Sorry I wasn’t able to download video.

[wolfe10]

Free play in that drag link end is completely different than play in the Sheppard steering box.


Hopefully, someone will have a part number for you, but barring that, extremely likely that a parts house catering to OTR trucks will be able to match it.


Be sure to measure "pin to pin" length before removing so you can get it back to the same length. That will leave steering wheel and cut angles correct.

[Saff57]

Thank you. How would you discern between Sheppard box play vs a bad pitman arm bushing? Not that I think all the play in the steering wheel is related solely to the pitman bushing.

[wolfe10]

Originally Posted by Saff57

Thank you. How would you discern between Sheppard box play vs a bad pitman arm bushing? Not that I think all the play in the steering wheel is related solely to the pitman bushing.

With engine off, have your wife turn the steering wheel left/right/left/right.... through 15 degrees or so each side of straight ahead while you look at the joints for movement. There should be none/every bit of input on one component should result in the same amount of movement in the next.


Check both ends of the pitman arm and tire rod ends as well. Also, there are U joints in the steering column-- look from below.


There will be some play in the Sheppard steering box. It is not adjustable and if excessive the steering box can be "blueprinted" by https://redheadsteeringgears.com/

[Saff57]

Thank you very much. You have been a great help

[SafariBen]

I find it easiest to have a weaker person or child wiggle the wheel, not try to turn it. Then you can feel and watch the movement on the output of the steering box through every joint. Put your finger or a tool against the less moving part of the joint, and "eyeball" the distance it moves. If the tire is moving, have them use less force. I've also done this by holding the input to the steering box in one hand and wiggling the U joint back and forth. That's enough force to find the "lost" movement.



Swapping to a TRW box is a common fix, as the TRW box can be adjusted to zero free play. My sheppard is tight enough for what I need, and not a priority.

[Saff57]

Thank you for the information

[Saff57]

Does anybody know of a shop in South Carolina that does the TRW swap?

[wolfe10]

Originally Posted by Saff57

Does anybody know of a shop in South Carolina that does the TRW swap?

Before you consider spending the $$$ to change to TRW, how much play do you have in your current steering box.


Again, you are looking for how much movement you have on the "in" shaft from the steering column that does not result in movement of the pitman arm.


I do not recall if this can be accurately checked with engine off or if there needs to be hydraulic pressure for an accurate measurement. Hopefully someone who has done this more recently will post.

[Saff57]

Originally Posted by wolfe10

Before you consider spending the $$$ to change to TRW, how much play do you have in your current steering box.


Again, you are looking for how much movement you have on the "in" shaft from the steering column that does not result in movement of the pitman arm.


I do not recall if this can be accurately checked with engine off or if there needs to be hydraulic pressure for an accurate measurement. Hopefully someone who has done this more recently will post.

I’m away from my coach, but I plan on checking the play in the steering shaft to the gearbox. Just trying to find out if there is a shop in or near South Carolina that has experience retro fitting to the TRW box.
Thank you for your response

[andy29847]

If I was going to replace the steering box I would ask Lee Shealy at Saluda Tire and Oil to do it for me. Lee’s shop doesn’t look like much, but they do lots of big truck work.

Also, I would stick with the Sheppard box. My box is a RH Sheppard M100PDP1. I just finished replacing the box this afternoon (with help). I was on the way home from Big Bend NP when my steering box sprung a leak. I called 6 truck repair companies in and around San Antonio on Monday morning and struck out at every one. My 7th call was to Weller Truck Parts. They had a steering box in Dallas and said they could get it for me overnight. It actually took 2 nights, but they did bring it to the RV park. I found a local ag mechanic (through the RV park owner) to do the heavy lifting for me. Believe me, it is heavy. I plan to start a thread with pictures when I get home.

[andy29847]

The bar from the axle to the pitman arm is the “drag link”. The ends on the bar are the same as the ones on the tie rod. They are standard big truck parts. This thread from years ago covers some of the same ground.

https://www.irv2.com/forums/f104/steering-linkage-tie-rods-and-bushings-266784.html

[wolfe10]

Originally Posted by andy29847

The bar from the axle to the pitman arm is the “drag link”.

The drag link connects the pitman arm to the steering knuckle.


Some of us have added a "compensating weight" to the drag link so the ends are more "centered".