The Oka manuals have good breakdown diagrams (Section 8 of the Parts Manual) and removal descriptions (Section 3 of the Service Manual).
If the column rattles over rough roads, it could be the UJ's which are worn or loose, or the sliding joint. The plastic ring inside the column indicator switch assembly can also rattle but that's unlikely to be the real cause.
You can check column wear by holding the lower UJ in your right hand under front of the drivers floor (without the engine running), whilst moving the steering wheel with the left hand. If there's any perceptible movement or clonking, something needs to be done.
If it's the top UJ, the only solution is a new column assembly as the top UJ is part of the shaft body. If it's the lower UJ, that can be replaced independently, but both UJ's will probably be worn by a similar amount. They don't have grease nipples. Note that there are two sizes of lower UJ, one for the original Kirby Bishop steering box and a larger one for the TRW box.
If the sliding joint rattles, it can be fixed fairly simply and at low cost. The shaft doesn't need to be replaced, or even removed.
Although it's a sliding, splined shaft, it spends most of its time working in the same spot and when the paint has worn off the piston shaft, it becomes loose and rattles annoyingly on any rough surface, even though it is still quite safe to use.
I have fixed my rattle by clamping an old urethane spring bush to the piston shaft and then securing that to the main body of the column using a piece of PVC pipe and 2 hose clips. I greased the shaft so it can still slide, but its movement is now heavily damped by the urethane bush and the rattling is eliminated.
The black Urethane Bush clamped to both the piston shaft and body of the column. |
A piece of PVC Pipe to prevent the clips from catching. |
The rubber boots, slit up the back to aid reassembly. |
Ensure that all the pinch bolts are correctly refitted to the UJs and fully tightened. I put additional lock nuts on top of the Nyloc nuts to ensure they wouldn't work loose.
Note that according to TRW, both UJ's should be refitted with the cross shafts facing the same direction to avoid "cyclic binding" if the UJ's are out of phase:
"Steering column assemblies with more than one universal joint (cardan type) can cause a cyclic binding feel or torque variation at the steering wheel if the u-joints are not in phase with each other".
I assume this to mean that the cross shafts of the UJs should be parallel.
Related Note: I have recently fixed a leak from the input shaft seal on our TRW steering box. See here for details.