Steering rack play

[AndreK]

I have a 1 year old live axle car with standard Caterham steering rack, very low mileage. There is not a huge amount of play at the wheel, but definitely some that can be felt at the 240mm steering wheel, say 10mm (not a precise measurement). Nothing is obviously loose. Is this normal? On 'normal'cars, mostly with PAS these days it is hard to determine what the play is, but my memory of old Minis and Imps tells me that any play should be small with a rack and pinion system.

[StewartG]

You could try adjusting the rack. The allen key bolt in the middle of the big nut.

[Mcalvert]

I had exactly the same problem recently and adjusted it out with the pre-tensioner nut as suggested. It has made a fantastic difference - I hadn't realised that the steering had been getting slightly sloppier as time went by, but now it's perfect.

 

The only problem I found doing the adjustment was finding a big enough socket (32mm from memory?).

 

There are other possible sauses for play - check on the 7vens mailing list archive and you'll find pages of advice,

 

Regards - Michael

[Alex Wong1697456877]

It is easy to tighten the adjuster and get the impression that the play has been dialed out but be careful as it only take a few degrees too much tightening to stifen the rack and reduce any feedback from the wheels. Check the front of the car for play at both ends of the track rods. Rod ends don't last that long. If there is play at the other end of the rod, it's a fairly big job to fix the worn rack and replacement might be a better option. I've recently had this problem and a new (2nd hand) rack is in the garage waiting to go in.

 

Alex

 

Alex Wong

www.alexwong.net

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[EFA]

STOP!!! and read this.....

 

There is a serious fault with the Std Caterham Racks (i.e. those where the body of the rack is a black steel tube.

 

You will find the 'play' exists at the inner end of the track rod.

 

To determine this, remove the rubber boots from each end of the rack (undo the inner clip and forld them inside out will do...) have someone sit in the car and more the steering wheel through the extent of play. If you have this problem you will see the internal mechanism of the rack moving (the big collar nut) but the actual track rod will not move. This should be a tight (but not binding) joint.

 

This is secured by a collar and locknut affair, which on the quick racks is doublely secured by a pin - not included in the std rack.

 

Caterham don't have a recall proceedure so the only way you find out about this is the hard way.

 

You can tighten the collar down with use of some big spanners (like about 40mm A/F ish) but you really need to remove the rack.

 

If you have to remove the rack I'd throw it back at Caterham and demand a new safe one.

 

If they deny you this and insist @ we've never had this problem before' be my guest and remind them they changed two racks for me for this precise reason...

 

If your rack is loose for another reason, plse excuse the blab.....

 

Arnie

[AndreK]

Thanks for the responses to one and all. From what I can see so far the play is within the rack itself, all other parts, ie t/rod ends, split joint on column, universal joint on lower column etc are all OK. The rack body has a large nut above the pinion with a large adjuster with small allen key hole within it, inside that. I will try adjustment first, I would not expect any wear at this low mileage. Does anyone know the 'spec for the rack lubricant? As I said the rack is the standard caterham with black alloy body, I think it may be known as the 8% rack.

[Andy Checkley]

Arnie,

 

Can you describe the "faulty" rack any further. My rack is a standard brand new unit with what looks like a cast black alloy tube. Is this the rack you are refering to. You've now got me worried as I will be doing a number of trackdays this year.

 

Are the "faulty" racks prone to dangerous failure (i.e. loss of steering control.), or just to much play?

 

Thanks.

[EFA]

The racks I am referring to are made of steel, not alloy.

 

They were fitted to all cars up until the alloy rack became the default. I'm not sure how recently this was - maybe as long ago as '96.

 

If you have an alloy rack the collar nuts are securted with a locking pin so there is no risk.

 

The racks to which I refer should take a while to undo to the point of complete failure, and the slack whilst it were loose would cause a severe lack of stability in a straight line (bit like driving on ACB10's but about 20x worse!)

 

AW

[Andy Checkley]

Arnie,

 

Thanks for the clarification. My car was manufactured last year, so from your details it seems my rack is a recent one and so should be ok.

 

Regards, Andy

[AndreK]

Firstly thanks for the replies. After considering these and threads on the 7 FAQ, I decided that the play should be able to be adjusted out. As I said first, the rack is the standard Caterham 8% black alloy bodied one. I was able to loosen the large locking ring nut with a 1 and 7/16 AF socket and then adjust the middle screwed thrust plate using a 7/32 allen key. Relatively little adjustment was needed. I did this with the front wheels off the ground to check for stiction. Seemingly this has worked well, there is now minimal play in the rack.smile.gifthumbsup.gif