Steering rack play R400D 2011

[slap_ed]

R400D 2011
I have play in the left hand side of my steering rack. There is zero play when the tie bar is push/pulled in and but a good 3mm when push/pulled up and down. I've removed the gaiter and everything is totally dry in there which I would think explains why things have worn prematurely. Should there be lubricant in there?
Looking into the end of the steering rack there appears to be a nylon toothed bush which is worn and allowing the 3mm play. See picture.

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Can you get replacements nylon bushes? If yes, where from?
Is this a diy job?
Does the rack have to come out?
Does it mean a new rack?
Will the rack come out through the side skin holes?

Titan are helpful without being helpful. They just say I need to go through Caterham themselves. I've read other "play in rack" posts and most end up at trying to adjust the large nut on top of the rack.

All help gratefully received.

[SM25T]

Is it still the same steering rack as on our cars from 2002 ? If so ... It should be well lubricated. I removed the gaiters and sloshed oil and grease on to the rack as I wound the steering from side to side. Wonder if those toothed nylon bushes screw in and out ... if so, does this affect any play ? On the 2002 rack I have, the big lock nut and adjusting screw you mentioned takes out any play. But you need to check for free operation of the steering from lock to lock with the wheels off the ground after adjustments and after you tighten the lock nut.

[Richard Price]

I've stripped and reassembled several racks, but as mentioned, Titan won't deal directly with parts that are Caterham rack specific :-( , and the only spares that Caterham generally sell are track rod kits and rubber boot kits. 

I've removed the play mentioned above by wrapping appropriately sized shim between the body and the plastic bush, but I don't recall the wear being anywhere near as much as that photo.

The rack has to be removed from the housing to be able to remove the bush, as the bush has a locating peg molded onto its outer face. The bush is also split so that it will fold inwards.

Incidentally, some racks don't have the bush. The rack simply runs in the alloy body.

I've made up a couple of good racks by salvaging bits from a couple of racks to make up one good one, and yes, there should be significant evidence of grease!

It's quite possible that an accident damaged rack would still have very usable plastic bush in it, so a "wanted" may bear fruit..... 

[Richard Price]

Oh, and to be pedantic, the item that is labeled "Pinion shaft", is actually the rack, as the pinion is the short shaft that has the serrated stub that the steering column universal joint is clamped onto.

[Richard Price]

'sorry, 'didn't answer your other questions:-

Does the rack have to come out?                                    -  YES
        
Will the rack come out through the side skin holes?        -  No

To remove the rack assembly, radiator needs to be released from its rubber mounts (but the hoses can stay attached), the rack has to be released from its mounts, the steering column, and the fixings onto the uprights steering arms(its also actually easier if the track rod ends are removed) , then has to be moved over to the passenger side until the driver side of the rack is all inside the chassis, then the drivers side is moved forwards, and will then pass out between the front of the chassis and the back of the radiator.

[slap_ed]

SM25

​I'm not sure if they are the same. Others talk about there being a bearing instead of a nylon bush like mine. There was a small amount of black/grey grease on the ball of the inboard tie rod but absolutely no trace of any lubrication on the rack that slides through these nylon bushes. A manufacturer quality control issue I think. There are no tight spots on the rack from lock to lock, everything operates smoothly. 

Richard.

Appreciate the detailed response. That clears up a lot of grey areas including getting the rack out of the car. I initially thought that it would be a new rack but now I'll pack out the bush as you've described.

I have a few more questions if you don't mind?

What sort of material did you use to pack out the shim?

What type of grease did you use? I wouldn't have thought you could use general purpose LM grease on something made of nylon.

I wrongly guessed that that shaft was the pinion. Thanks for the info.

Thanks to you both.

 

 

[Richard Price]

I will have used steel shim material, which is often available in a selection of thicknesses.

A quick search of ebay should find shim material (of sold in sheets 4" x 10")

I would be looking to check exactly how much clearance you have between the OD of the rack and the ID of the bush (which does look quite extreme in your case) using feeler gauges. I'd guess that yours has worn quite oval, so you need to check the full diameter, and then shim to suit the smallest gap you have.

Then cut multiple strips the full width of the bush and enough to wrap almost the full diameter (so that they do not overlap causing a high spot), and punch a hole to clear the locating spigot (its quite likely that a paper hole punch would make a suitable hole as long as your shim material is not too thick).

Yes, I'd use a general LM grease.

You'll need to completely dismantle the rack assembly to extract the rack from the housing. The track rod retaining cups are locked in place with a soft steel dowel that needs to be drilled out before the cup and locknut can be removed. This dowel is fitted between the joint between the cup and the lock nut, and actually through into the rack its self. You'll need to carefully drill concentric to that dowel, removing all of the dowel, or you'll struggle to unscrew that cup and locknut. when you refit, you'll need to adjust the cup and locknut, then drill a new dowel hole before fitting a replacement dowel and peining over to lock it in place.

[Tony Whitley]

I have recently done this on my Elise which I think is similar (it's also a Titan rack) and according to the experts on Seloc there's a special grease. I've lost the details but here's a starting point http://wiki.seloc.org/a/Steering_rack  It's certainly not swimming in oil/grease like the rack on my old 7.