Play in S3 rack

[Chris71]

Hi,

 

I've got some rotational play in the steering, which I'm fairly sure is coming from the rack itself.

 

It floats for about +/- 5 degrees when unloaded, with no steering within that envelope. Once you take up the slack you can feel what I'm guessing is the next tooth of the pinion coming up against the rack and then it feels normal.

 

What do you reckon this is, and how would you go about conclusively diagnosing and fixing it?

 

Cheers,

 

Chris

[IKB]

I had a similar problem........but it was the steering column joint and not the rack. Worth checking this first.

[Chris71]

As in the UJ just before the rack? Nope, I've changed that (there was a little bit of play there and also some friction, so it was worth doing, but I'm 90% sure the current issue is in the rack itself).

[akakubi]

If I am not mistaken, there is an adjustment bolt (allen I think) on the rack itself. You may try adjusting that (not 100% if this would work though).

[Chris71]

Kind of a pre-load type thing? I think I've heard some reference to that before.

 

It does sort of feel like it needs a spring keeping the teeth in contact between the rack and pinion (that analogy may be completely wrong, but it does feel like that to the nut behind the wheel).

 

[Tony Whitley]

"As in the UJ just before the rack?" More likely the clamp just in front of the scuttle.

[Chris71]

"As in the UJ just before the rack?" More likely the clamp just in front of the scuttle.

 

This is rotational play though - wouldn't a problem with the clamp just result in movement of the steering column?

[Tony Whitley]

No, rotational. Unless the centre pin is gripping the lower column tightly you'll get a very noticeable nothing-then-everything-normal slop at the steering wheel. A better description is the clamp just ahead of the scuttle. Hold the lower part and turn the wheel, you'll soon see if that's where the problem lies.

[IKB]

*arrowup*That was the one

[Chris71]

Ah, sorry. Will investigate.

 

Many thanks!

[Ged]

There's a few things that could cause the looseness you describe.

Steering wheel loose on the splines, particularly if a Q/R type.

The sliding joint between the upper and lower columns, the clamp can work loose, or bend and crack.

The UJ, near the rack, but you've replaced that.

The rack itself. This can be adjusted. Loosen the 36mm? lock nut, then turn the tensioning screw slightly clockwise with a 5.5mm allen key. I would do this with wheels raised up as it's very easy to over tighten, at least then you'll be able to feel any tight spots and back it off again. Check the steering again after tightening the lock nut, as it invariably moves the tensioning screw slightly. Probably worthwhile to lubricate the rack whilst doing this.

The track rods or track rod ends could be worn.

[Chris71]

Does Blatchat have a 'I've been a numptie and failed to check something I should have looked at earlier' smilie?

 

I had a look last night and found a slightly alarming, but easily remedied reason for most of the play. The new UJ I talked of was loose. Not 'come off in your hand' loose, but enough to introduce quite a lot of play. Quite how this happened I don't know as it was tightened well before and it's got nylocks on there...

 

One of the great things about the Seven I've discovered is that, being quite compact, it's just about possible for an ordinary size person to grab any other part of the steering system while reaching round and waggling the steering wheel! As a result I'm fairly confident all the rotation at the wheel is now making it at least as far as the pinion. There is a tiny bit of movement remaining, but I only did a quick check so it was difficult to tell if that was in the rack, the rod ends or simply natural flexing of the sidewalls.

 

One thing that I did notice is that there's a small amount of up and down movement of the column (when you're UJ is loose enough to allow it!) which is a little disconcerting. But when it's such a long unsupported length in front of the two bushes it seems almost innevitable and the UJ does locate it at the other end. Is it possible to eliminate this completely do you reckon?

 

Thanks again for the advice.