Power steering rack play
Power steering rack play
Author
Discussion

KKson

Original Poster:

3,466 posts

146 months

Tuesday 4th April 2017
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Well despite new front and rear suspension bushes, repaired A frame, new track rod ends, new steering column UJ and new steering column lower bush the handling of the 390 is just not as sharp as that on the 350i. The car passed it's MOT the last few years with no issues re the steering but to me the steering is vague, a bit like driving an old Landrover. So tonight I've jacked the thing up again and got my lad to wiggle the steering wheel. It does look like it's the rack that's worn as you can move the steering wheel 2" to the left and to the right with no movement at the wheels but movement into the rack input shaft.

So before I pull the rack out and send it off for refurbishment is there any way to simply nip up a bit of float? Is adjusting the pre-load a specialist job or has anyone tried adjusting it at home with any success?

Thanks.

GV

2,366 posts

245 months

Wednesday 5th April 2017
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I had some play in my steering only last week following some spirited fettling runs designed to reveal any issues in the car. After a check on the condition of the steering UJs (which are both new) I found the lower UJ that connects with the rack had a loose nut. I was able to tighten it and this little problem sorted out the play. Might be worth checking to see if all is as it should be with the UJs. If you still have a concern over the rack give Kiley Clinton a call - very helpful people and they will give you a likely cause if the UJs are all tight and the problem remains.

mrzigazaga

18,740 posts

186 months

Wednesday 5th April 2017
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Hi Keith


Definitely check the bolts as one of my top UJ bolts were not tweaked up as much as it could be and I had around 1.1/4" play ...

You will need another person to check this.....Remove a front wheel and get someone to gently rock the steering wheel about 2" left to right and then see if the play is visible at the hub, if not then it is most likely the internals of the rack that are worn.....

I did hear that someone sent a rack off to KC and they sent it back and it still had play in it, When they asked they were told that they couldn't get the part anymore...Not sure if that was a Cortina mk4-5 power rack or the TVR "Supra" rack???...


Ziga

KKson

Original Poster:

3,466 posts

146 months

Wednesday 5th April 2017
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Hi, all UJ's and bolts are good. The play is definitely in the rack. The question is has anyone ever tried to increase the pre-load to overcome rack wear? The car has only done just over 50,000 miles so surprised if the rack can be that worn.

gmw9666

2,739 posts

221 months

Wednesday 5th April 2017
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Is it a power rack? You can buy new manual cortina racks for a £100 ish

KKson

Original Poster:

3,466 posts

146 months

Thursday 6th April 2017
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gmw9666 said:
Is it a power rack? You can buy new manual cortina racks for a £100 ish
Yep power rack. I'll give Kiley clinton a call today as ask their advice. There no point having the car if I don't enjoy driving it so need to get it sorted.

Yatesy350i

1,010 posts

157 months

Thursday 6th April 2017
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Had my PAS rack sorted by KC a couple of years ago Keith. They said they had quite a few racks on the shelf (Supra) for future refurb or spares.

Regards Karl.

KKson

Original Poster:

3,466 posts

146 months

Thursday 6th April 2017
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Yatesy350i said:
Had my PAS rack sorted by KC a couple of years ago Keith. They said they had quite a few racks on the shelf (Supra) for future refurb or spares.

Regards Karl.
Spoke to them earlier - they now do not have any spare racks but they can get hold of all parts required to refurbish the rack. They did say that the input pinion is "floating" and some adjustment is possible via a nut underneath the small oval inspection plate. They suggest trying a quarter turn to see if the small amount of slack can be taken up. If not then they can strip and refurbish if required, with turnaround in less than a week.

adam quantrill

11,625 posts

263 months

Thursday 6th April 2017
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Clockwise or anticlockwise?

KKson

Original Poster:

3,466 posts

146 months

Thursday 6th April 2017
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adam quantrill said:
Clockwise or anticlockwise?
Clockwise, a quarter turn at a time. If the rack starts to "snag" then back a quarter turn. Not a clue if it will work or what the hell I'm looking for underneath the blanking plate but worth a try.

KKson

Original Poster:

3,466 posts

146 months

Friday 7th April 2017
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Okay, so the info K&C gave me earlier was total rubbish. Having now removed the rack inspection plate there is no adjustable bolt. The inspection plate has a set of shims underneath it which impacts on the rack pre-load. Mine had three shims under the main inspection plate so I tried removing one of them and nipped things up tight again and rack was then way too tight, so I've put it back as was. If I could get a thinner shim then maybe I'd have some success but so far no progress.

Inspection plate and associated shims as found:


Pre-load spring inside the steering rack:

Hamish400

276 posts

278 months

Saturday 8th April 2017
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Suggest following:
(Hope I am not teaching you what you already know!)
Measure thickness of shims using micrometer or vernier. Remove thinnest shim (or one shim if all same thickness). Test Assemble using two sets of feeler blades inserted to simulate the thickness of the required shim. Thickness of feeler blades to be less than the shim removed. Eg if removed shim is 0.3 mm use 0.2mm feeler blades.
Try different feeler blade thicknesses to establish the shim thickness that gives minimum rack play. Then make your own shim out of suitable shim material.

Rgds
Hamish