Steering shaft

[gogmorgo]

6 hours ago, eaglescout526 said:

That’s good info. I didn’t know that. I guess what bothered me the most was that the steering wheel never returned to full center after making a turn and I assumed it was due to slop. But knowing this tidbit helps me understand the steering system more and will tell me to quit fiddling with it. 

Thinking more about it, slop isn't a great way to describe the way the torsion bar works, because it's twisting, not really having slop. If you turn the steering wheel with the engine off, you can feel it winding up and springing back. Like all springs it is possible for the torsion bar to weaken or fail, in which case it and the steering wheel won't return to the valve centre. One of the other side effects of the torsion bar in there is that when the road steers your wheels you'll feel the push in the steering wheel and push back and correct, possibly even unconsciously, but if the torsion bar fails you don't get that feedback and you'll have to constantly correct what feels like erratic steering wander. There's a loose interlocking fit between the valving parts and the worm shaft that allows the torsion bar to twist and do it's thing but that prevents you from excessively twisting the torsion bar or losing manual steering control if the bar fails. Going back to pushing the steering wheel with the engine off, after the springiness there's a bit of a bump at point where you really start pushing the steering components, which is running into the end of the torsion bar's wiggle room, so to speak.

I imagine a torsion bar failure could feel a lot like excessive slop, especially when you're saying it doesn't seem to return to centre, although I don't know for sure I've experienced it firsthand. I also don't actually know how common a problem it is, but when we were rebuilding the steering gearboxes in school our instructors made sure we knew it was a thing that could happen. I don't know if that's part of a typical automotive curriculum, but in the heavy duty world it's still pretty well the only type of steering system in use with only a few exceptions, and the cost of a new gearbox for a heavy truck is still high enough it's worth paying shop rates to have it rebuilt.

I was trying to find a picture of the components online, but this is actually a pretty good writeup to learn more about how the whole system works, although my browser doesn't seem to be putting the pictures in the intended locations.

https://www.motortrend.com/how-to/power-steering-103

[AZJeff]

18 hours ago, Minuit said:

It should be if the column has not been involved in a wreck or otherwise jostled. The shaft in the steering column is actually two pieces, once again connected with an injected plastic crash structure to allow the column to collapse in a wreck instead of skewering the driver. If this crash structure has broken, there will be slop in the column itself. This is the reason why you'll very often see warnings to handle a dismounted steering column very carefully. Hammering on this shaft could very well break the crash structure.

 

I have a NOS one for a tilt column in my attic that I could take a picture of to show you.

I am guessing, based on the description of the lower steering column you stated above, that there was some sort of change to the column during the "body refresh" on the XJ in 1997.  

 

My column is from a 2000XJ (along with the dash), and the lower portion of steering shaft is a solid rod with two "flats" on it, forming what an engineer calls  a "double-D" shape.   The upper shaft section is a hollow tube with the same shaped "double-D" on the inside.  The two pieces slide into each other, and don't seem to have anything to prevent them from sliding in or out until the respective halves are connected to the body and the steering gear, respectively.   You can literally push the lower solid section up into the upper hollow part without using a hammer (I greased mine to help with this.)

 

Oddly enough, this same type of joint was used by Ford on my old 1991 F-150, and that shaft developed some slop in that "double-D" slip joint.  I fixed it by drilling a hole on one of the flats on the "D" of the hollow portion.   Then, I welded a nut on the outside over the hole, and used a set-screw and a locknut to take up the slop between the two halves.  Note:  I did NOT tighten the set screw to the point that the shaft could not telescope.