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Recently, my steering column has been able to move up and down on the pinion, despite being aligned and fitted with the correct pinch bolt.

Before I get into trying to find another, has anyone got any examples of a knackered set of spines, and a good set of spline so I can compare?

At the moment, the end of my column is completely closed up but was able to slip off the end of the pinion, so no more tightness to be had..

Had the same problem some weeks ago.

Just pull it out, then recut the groove with a Anglegrinder and you should be able to retighten it again.

I used to change the bushing and felt at the same time...

Concern is that the splines are too worn to engage correctly now - I'd like to have some way of determining that

I think that you ought to elaborate on that a bit FanFan.

Can we accept that you mean widen the groove that allows the pinch bolt to tighten the column splines onto the pinion splines?

Not my idea of a fix as such because there is already a reasonably wide groove there already.

Do you have an original BL steering rack Gary? Or a £75 repro? I'll send/lend you a good splined pinion to try

It’s a crappy Minispares repro. I have the original but that needs a rebuild (I’ve earmarked Andrew to do this!)

For now though, I need something that works and is safe.

Here’s what’s the splines look like.

I'm with Fanfanracing, just grind out the slot. I did it once myself and it worked fine.

The problem, as we now know it Larry, is that the good steering column is actuating a crap repro steering rack. And there's nothing that is going to fix that. It is a problem that is reasonably well known too. That's why I asked

Even with completely mullered splines, I don’t see how/why you are able to pull the column off the pinion with the pinch bolt in place. The groove, with the correct bolt in, should be far too deep to allow that.

I can’t pull it off without removing the pinch bolt but it certainly will move ‘in and out’ against the pinion.

Ah OK - I misread your post. Sorry.
Are you sure it is moving in and out on the splines, and not moving the pinion as well?

I think as others have said, widening the slot will probably see you right until you get your other rack sorted.
I’ve seen columns with worse splines - almost smooth!

Surely even with worn splines, the un-threaded part of the bolt will prevent any movement.
The splines are there to aline two parts and the bolt to firmly tighten together. How would splines ever wear, they are not moving parts. Even with a loose bolt, there will be very little movement as its sits in the recess on the rack.
Do the aftermarket racks and columns not have exact matching spines. I appreciate even a slight difference will make it difficult to smoothly slip together.

If the pinch bolt cannot tighten the column fully to the rack then there will be slight movement up and down

Good point. I think we’re back to the idea that the pinion is undersized..
mtge rack on my car only has a half moon cut out, not the 360 degree cut seen on the mk1 original rack. That in my mind does mean should thebsolines fail to grip, the bolt will still turn the pinion. That said, if the column is loose on the pinion, then it will tend to fret left to right, eventually wearing the splines down and exacerbating side to side play.

I’m not seeing left to right play, but in and out play even with the bolt tightened all the way.

Then it's likely the villan is the rack, not the column.
Have you checked the 'U-Bolts'? Maybe it's simply the rack that loose.

Yes U bolts are tight, no movement in the rack, pinion doesn’t move, everything correctly located.

What measurements, or inspections can I do to determine which component is most at fault, or beyond acceptable tolerances for sizing or wear?

Have this issue on plenty of customer's cars.

In my experience spline wear is caused by poor re-assembly where a person without knowledge of how to secure the column and pinion together correctly has failed to insert the pinch bolt through the groove in pinion and has instead fitted it above and then relied on the tension of tightened bolt to hold everything together.

Another cause I see is where the column and pinion are misaligned so an undersize bolt gets jammed in which of course won't tension the clamp sufficiently. As the bolt is not a tight fit it does not lock the two parts together under rotation allowing splines to wear. It's also important to fit a shouldered bolt to ensure it's a very snug fit against the pinion, unlike a fully threaded bolt.

If you are unable to visually see wear in the splines then proof of wear can be established by careful assembly and checking. As others have suggested, run a cutting disc through the clamp area to open it up, carefully align column and rack pinion, fit a fresh shouldered bolt and fully tighten. I then refit the top column bolt loosely just to hold column in correct position and check for up and down movement. If that checks out OK I then secure the top bolt and do a rotational check. If the splines are worn movement can be detected.

I've also fitted plenty of the Minispares replacement columns and would not describe them as crap at all. The purist won't like them as the design is to the later spec requiring the outer column sleeve to be shortened at the base for clearance. But, the positive to this is you can then use the later style lower nylon bush which is much better in service than the old style oil soaked felt bush.

That column has been run for years with the pinch bolt not correctly done up. There is NO WAY That the splines could have got that bad with everything nipped up correctly.

I wasn't aware that Minispares made a MK1 steering column?

There is absolutely no point whatever in over complicating this important safety related issue.

There is also absolutely no mileage - if you'll excuse the pun - in bodging it, either by deepening the slot, over tightening or any of the other palliatives that are not a real cure. Abandon the cheap £75 repro rack and replace it with a Nick Rogers Mini-E-Bitz (or an Andy S ....) rebuilt and tested rack of a known quality.

(Off at an angle now, same meat, different gravy. Quite how you can get a nylon bush at the bottom end of a steering COLUMN is a mystery to me Kiwi-Minibitz. You CANNOT fit a nylon bush from the bottom end because of the through-bolt lugs. And it won't go down from the TOP end because the upper diameter is simply too large)

I wrote a long instructional and non too technical essay about rebuilding columns AND racks for the Forum a couple of years ago. Based on nothing more that my total lack of expertise in technical matters over the years. But, alas they've disappeared into the bowels of the forum......somewhere

Well, I’ve measured the pinion this morning and compared it against the original. 0.555” on the repro, 0.5552” on the original. So, I think the pinion ont he repro rack must be ok, leaving just the wear on the splines.

Difficult to measure the internal size due to the splines, but the measurements with no bolt in all came as a little smaller than 0.555”.

Can anyone confirm what the appropriate measurement are?

There’s a possibility of a better column from Andrew Sparrow, but I’d like to know what I’m looking at. No point fitting a better column to find that this problem reappears shortly and another column is ruined.

Personally, I would not re-use that column, I think the fact that you can no longer tighten it up shows how much the splines have worn.

What happens if you hit a kerb and the rest of the splines shear.......dosent bear thinking about.

Best in the bin