16 replies to this topic

[JackF]

Mini is off the road.

I think I've ruined some the splines at the base of the column.

When parking (i.e no wheel rotation) the steering wheel has jumped on the splines, not turning the wheels.

I know this is dangerous. I'm on a budget and a small timescale.

 

Tomorrow I intend on removing the column and assessing the splines at the base. I hope I dont need a new rack as I dont really have the time before I start my new job monday.

 

Can anyone give me some guidance as to replacing the inner column? My car is fitted with a column drop bracket, could this have caused excess stress on the column/rack joint? How broken is it going to be?

 

Any help guidance would be lovely.

 

It's an 84, CityE.

 

Taaa

[miniman24]

IF its the splines on the joint between the column and the rack, it is very unlikely that the rack splines will be damaged as the column is made of a softer metal so nearly always fails first, so it should just be a case of replacing the column :) But it could be a problem in the rack itself, in which case it sounds pretty dire, a new rack will be needed.

 

Edit: And yes, the drop bracket could easily be the cause, when fitting one the rack u-bolts need to be loosened and the rack re-aligned so that the splines line up correctly in the joint between the column and rack, then the u-bolts need re-torquing. If it wasnt done like this, then its only a matter of time before the column splines wear away.

Edited by miniman24, 04 September 2013 - 08:37 PM.

[robminibcy]

excuse my ignorance but how can a coloumn move without the rack moving as the pinch bolt goes in to a cit out in the rack? Or was there no pinch bolt fitted in this case?

[Earwax]

Totally agree with miniman24,   to answer question - the drop causes the column spline to place pressure upward, even though the cross bolt is there over time this enables the small splines to ride over the top of the harder rack slpines ( they are only about .5 mm deep after all.

 

So undo Both sets (2 x 2) rack nuts , and on refit do them up last.  On refit also get a proper high tensile bolt ( i think they are 1 5/16 length and Tensile 8?  or something (check this)  ie NOT just any old bolt.

 

Ask how i know...... my splines let go due to wear on a khanacross course,  luckily low speed straight ahead but not something i would recommend.   

[JackF]

Many thanks miniman24, sounds like my thoughts were along the right lines! I will remove the column at some point today, Report back and then decide the best plan.

Totally agree with miniman24,   to answer question - the drop causes the column spline to place pressure upward, even though the cross bolt is there over time this enables the small splines to ride over the top of the harder rack slpines ( they are only about .5 mm deep after all).
 
Ask how i know...... my splines let go due to wear on a khanacross course,  luckily low speed straight ahead but not something i would recommend.

Thanks for the better description than mine, hope you were ok!

All responses are greatly appreciated.

[JackF]

No splines left!

Cause?

[Earwax]

on fitting new column, people often take a hacksaw to widen the collar gap ( to about two hacksaw blades wide) this allows for true grip pressure on the rack splines , if the sides of the collar touch you cannot go tighter

 

just thought of it looking at your great piccy of the well worn spline)

[JackF]

on fitting new column, people often take a hacksaw to widen the collar gap ( to about two hacksaw blades wide) this allows for true grip pressure on the rack splines , if the sides of the collar touch you cannot go tighter
 
just thought of it looking at your great piccy of the well worn spline)

That would make sense, allowing the column to be tighter against the splines on the rack

[cal844]

^^ i use a thin grinding blade on an electric drill, with the column clamped in a vice

[tiger99]

That does not actually work. If the gap seems to be too tight, it is because the splines are worn. Making the gap wider allows the clamp to close tighter, but because the splines were originally spaced at the correct angles around the circle, they will be at closer angles and most of them will not line up properly. What actually will happen is that one or two splines will end up carrying the entire load, and the rest of them will be distorted, and possibly sheared, as the bolt is done up.

 

If it needs the gap widening, it must be replaced for safety's sake. This item is the main killer in Minis.

[Pete649]

I have noticed on newer steering column inners there is an area without splines adjacent to where the pinch bolt fits through the splined hole. In other words, the splines only run around approximately 4/5 th's inside the bottom of the inner.

When the inner is assembled onto the steering rack fixed by only the clamp bolt to the rack it can move (rock) slightly in one plane, probably due to the small splinless section adjacent to the pinch bolt. Seems to be OK when the column clamps are used though.

[Vipernoir]

Some of the later racks have the pinch bolt groove going all the way round for ease of fitment.

 

Bloody lethal, as although it prevents the column coming off the rack, it doesn't stop the column spinning uselessly on the pinion if the splines fail.

Guess how I know...

[tiger99]

All those I have seen had the groove all the way round. Even if not, the pinch bolt will not transmit any real torque on its own, and will just bend out of the way. I have experience of a pinch bolt failure, not on the steering column, on an unrelated car, which actually allowed the shank of a ball joint to pull out. The bolt being apparently in the groove provided no real retention at all.

 

People were being killed by steering failure way back in 1960 or thereabouts, when the drop brackets first appeared, which resulted in BMC issuing severe warnings about their use.

 

The bracket in the photo shows evidence of significant stress raisers, due to poor manufacturing, and I would not have such a thing on my car, as it may well fracture. It also shows very clear evidence of having being adjusted in-situ, which is probably what ruined the column.

 

Amateurishly  designed aftermarked bodges are never worth the risk.

[GuamMini]

Wow Interesting, I just removed my column to remove the ignition switch shear bolts. Now my steering column pulls up and down. But it turns fine,in any event I will see if maybe the column is not deep enough into the rack pinion.

 

How tight is that pinch bolt supposed to be?

[nicklouse]

Nope. The inner colum is held in place in a cut out/groove on the rack. The outer is free to move.