Steering column taper pins

After the problems with the clutch shaft taper pins I am now looking at the pins in the column. These are more important and I would guess have at least the same stress. Do you think the parts would have been taper reamed together? I can’t get the taper on mine to fit all parts at the same time. Would it be acceptable that only the thickest part of the pin does the job? I don’t see new pins would fit properly any where based on my previous experience.

Looks like you need to either find an engineering shop that has a selection of taper reamers or purchase the correct one to match ream the holes. The last one I feel would stat to fret.

Making some progress … I wonder how many people get an exchange rack and just bolt it on?


FWIW, my car had tapered cotter pins threaded at one end so held in with a nut and washer as well as the taper. That’s what I put back. That is also what is shown in my parts list in Plate AD. The parts are:

C6330 Taper, securing lower column to Pinion and Upper Steering Column
NN.125/L Nut on Taper Pins
C724 Washer, shakeproof, under nuts

That’s a bit like pushbike pedals from when I was a kid.
The clutch shaft has a 1 degree taper and the two parts , shaft and yoke are reamed in situ so the pin pulls up tight against both surfaces.
A tapered reamer is not tat expensive and can be use dina normal tap wrench
If it doesn’t pull up tight on both surfaces , it will 'work 'and wear.

Here is a good vid of how to ream tapers. Another factor I have thought of is that because the collar and shaft have not been drilled together if the fit us too tight the reamer could cut an oval hole . I think it would be difficult to line the holes up exactly by eye.

I’m not clear about your intention here, Jim. The taper pins in your previous video appear not to be threaded. Are you going to cut a thread when you have the pin seated in the taper?
I’m not convinced that the yolk part is tapered on both sides. I’ve got a spare somewhere. I’ll have a look for it. The threaded part of the pin must be parallel so the hole on the nut side doesn’t really need to be tapered.
I think using a tapered pin in this application is overkill anyway. A Nyloc nut and bolt would be perfectly OK.

You can see why the British motor industry turned to a splined shaft with a split yoke and pinch bolt soon after. Much cheaper and easier to mass produce, and certainly easier to service later. I certainly wouldn’t fit a tapered pin without a nut to retain it, and I agree with Eric that the tapered pin is probably overkill anyway, but as the yoke isn’t split to clamp the shaft I don’t think I’d want to go with a parallel bolt shaft and Nyloc. Although I guess it’s not really a rotating shaft, so maybe… you pays your money etc.


Actually, I was just about to correct myself as I told Jim that E Types had a plain bolt and nut. Then I went and had a look and of course, realised that while that is true, the fitting is splined as you mention. Thinking about it, I remember that the pinion splines are necked at the bolt position so that the pinch bolt not only clamps but also has a positive location in the shaft. This prevents the yolk and shaft parting company even if the bolt wasn’t fully tight.

Yes, it’s a much safer system and easier to service. Pretty much everything moved over to that design in the sixties, and most of the modern stuff I look at still has it. Yes, there’s a locating groove so you can’t just loosen the bolt to disassemble, you have to physically remove it.

My conclusion…

Having worked in quality control in an engineering environment I would have thought that those holes would have been drilled on the centre line of the shaft/bore, in jigs, and as a toolmaker that would have been one of the jobs that the toolmaker would have had to do. Make it correct!
We can only assume a few things from the video.
Are the holes parallel? We can’t tell as you only show the pin going in from one side.
I still feel that there would be sufficient meat to gently taper ream the holes to a matching fit and then thread the protruding end to finally secure the taper in place.

All holes are tapered. I will talk to the rack reconditioners tomorrow to get their view. If the assembled parts are reamed for the final fit then I think all the pins may have to be threaded different amounts depending on how much it pulls through?

Fun fact for tool-lovers. Imperial/SAE taper pins are tapered 1/4 inch per foot, or 1 in 48. Metric taper pins are 2 cm per meter, or 1 in 50. So if you want a well-equipped amateur machine shop you need two sets of taper pin reamers!

Luckily, the taper angles of BSPT and NTP pipe threads is the same–1 in 16–so you only need one set of pipe taper reamers for both.

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Just spoke to the reconditioners. The new pinions are hardened steel and cannot be reamed. They say a “soft” pin should take up any slack. They have not come across this question before and they supply a lot of these.

…which probably proves you’re overthinking it!