14 replies to this topic

[trtj]

Hi there, relative newbie here. Finally having some time to work on my 71 clubman rally project. I posted on here a few months ago and have a small log over on PH but will start a project thread here soon.

 

Anyway, I have knocked something out of kilter with the steering when i gently understeered into a grassy verge a few weeks ago on a soggy road. (Hangs head in shame) I immediately pulled over and got the lamp out (it was 12am). No visible damage to anything apart from the steering wheel is now pointing to 10 oclock not 12. I understand it can be one of two things or both...

1. Splines between column and rack pinion have slipped/stripped

2. Rack has moved on body.

 

No. 2, how can this happen though? The hole in the car's body for the rack pinion surely prevents any lateral movement even if the U bolts have slipped. The pinion goes through this whole so I dont understand how it could slip side to side?

 

I have a spare rack but at the moment I dont want to have to drop the subframe/engine!

 

Thanks all

 

[Carlos W]

Slipped splines?

 

I would inspect the splines on the rack and column VERY carefully and make sure everything is ok. If the splines are damaged and it has jumped then replacement parts will be needed. 

 

Also, check the pinch bolt isn't loose before you remove it, this will cause the splines to be able to slip

 

Are both the wheels facing straight when they should be? 

[mk3 Cooper S]

I have had well worn steering racks jump a tooth in the past.

[trtj]

The steering rack is actually quite a new one and there is absolutely no play in it, and yes I have checked the alignment and everything is in order. I read on here that the rack can slip on the body if the U-bolts arent tight but I just dont see how thats possible more than +- 2mm as the pinion goes through a hole in the body!

[trtj]

Slipped splines?

 

I would inspect the splines on the rack and column VERY carefully and make sure everything is ok. If the splines are damaged and it has jumped then replacement parts will be needed. 

 

Also, check the pinch bolt isn't loose before you remove it, this will cause the splines to be able to slip

 

Are both the wheels facing straight when they should be? 

I suspect it isn't the splines as it'd need an awful lot of torque to strip them. I suspect I'd let go of the wheel by that point! But I will inspect as you say. Is it case of removing the pinch bolt at the bottom, removing the drop bracket and pull upwards?

[Carlos W]

 

Slipped splines?

 

I would inspect the splines on the rack and column VERY carefully and make sure everything is ok. If the splines are damaged and it has jumped then replacement parts will be needed. 

 

Also, check the pinch bolt isn't loose before you remove it, this will cause the splines to be able to slip

 

Are both the wheels facing straight when they should be? 

I suspect it isn't the splines as it'd need an awful lot of torque to strip them. I suspect I'd let go of the wheel by that point! But I will inspect as you say. Is it case of removing the pinch bolt at the bottom, removing the drop bracket and pull upwards?

 

 

If the pinch bolt is loose then it is possible to damage the splines.

 

If the U bolts aren't loosened when the drop bracket is fitted then the rack and column don't end up square to each other and damage can occur.

 

Removal should be as you describe

[Yoda]

As Carlos says, splines will go if bolt is loose. The column splines are only mild steel, the rack splines are hardened. If you find this is the area of concern, you will need a new inner column and while its off, replace the upper and lower bushes.

 

Less than an hours work to be honest.

 

Hopefully thats all the problem is.

 

Do not be tempted to modify the old column to make it go tighter, it wont work and may kill you and your passengers.

Edited by Yoda, 19 May 2014 - 11:04 AM.

[RedRuby]

It could possibly be the splines, you mention removing the drop bracket, did you fit it or inherit it, if it was fitted originally and the steering rack was not adjusted to line up with the splines on the column it may have caused damage which has now shown itself.

[trtj]

I fitted the dropper. I loosened the U bolts and made sure the rack could wobble into line nicely to mate nicely with the column splines so everything was concentric before tightening the pinion pinch bolt. I remember the last thing I did was tighten the U bolts. Something has defintely 'shifted' with the impact, I hope this week to have an answer with a few dry evenings fingers crossed. Thanks for  all the replies.

[Ethel]

All the above, the splines on the rack are undercut with a nice stress relieving radius so it can move a bit more than you might think. Other possibilities are the subframe has moved relative to the rack; a bent steering arm or tie rod (or split rubber bushes); collapsed suspension (knuckle joint?); binding brake. It could even be a fault at the rear end.

[Yoda]

With the possibility of a loose bolt, there is scope for the mild steel splines to jump one tooth, taking half the depth of the splines with it, if left, the splines will wear more, and eventually the bolt will either wear or snap. Not what you want to happen when doing 90 down the motorway. If you cant see anything obvious, it is imperative that you at least remove the bolt and inspect it for wear and also slide the inner column off the rack once the top mount is undone and inspect the inside of the splines. if all is well here we can look at such things as a displaced rack, bent steering arms on the hubs, bent track control rods and steady bars etc.

[Yoda]

Go now i will. Ethel is on the case.LOL

[trtj]

Don't worry Im not going to drive the thing till inspected. To rule out major bending of parts I have run a 4 wheel alignment as a precaution! Everything is still to my settings, so this puts my mind at rest a little.

[Yoda]

In that case, its almost certainly the splines have jumped.

[62S]

It doesn't take much movement of the actual rack to alter the steering wheel as you have described.

 

You don't say if it is actually pulling to one side since the incident.