Lotus Elan

Steering "Play" and Front Wheel Bearings

PostPost by: david.g.chapman » Sat Jan 01, 2011 2:55 pm

There is about 1/4 of an inch of play in the steering wheel of my +2 before the front wheels move.

At the last MOT there was a comment about it, so I have just done a quick experiment. I jacked up the front of the car and took all the play out of the front wheel bearings. Popped the wheels back on, lowered the car and tried the steering again - no play!

Is this usual for our cars - a bit of play at the steering wheel for correct front wheel bearing adjustment, or am I giving these bearings too much play? I try to aim for 2 to 4 thou end float, or about 1 mm rock on the tyres.

Dave Chapman.
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PostPost by: andyelan » Sat Jan 01, 2011 3:10 pm

Hi Dave

I've just put the front end of my Europa Special back together after fully rebuilding everything, steering rack, inner and outer ball joints, trunions, wheel bearings etc. Now with everything correctly adjusted there's no free play at all at the steering wheel so I would suggest that is what you sould be aiming for.

I would think 1/4" of free play is alot if it is indeed caused by movement in the wheel bearings.

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Andy
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PostPost by: 69S4 » Sun Jan 02, 2011 8:41 am

That much free play at the wheel does seem excessive no matter how it's caused. I'd be taking a closer look at the flexible coupling between the steering column and the rack. Wear there does give that sort of movement at the steering wheel.
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PostPost by: david.g.chapman » Sun Jan 02, 2011 9:56 am

Thanks for the replies.

I would be surprised as well if there was play at the steering wheel with new components and correct front wheel bearings - so I had another check.

If the rack is turned through its travel, then set to the straight ahead position - there is no play. However, if the car is left for a few hours, then a bit of play reappears (about 2-3mm) as you move the steering wheel with a knock heard as the play is used up. I suppose it is a sign of the cold weather here, and an effect of the grease in the rack.

All this is with the front bearings set for zero play.

I will get someone else to wiggle the steering wheel while I see what's moving - my guess its the pinion shaft in the rack, or the rack itself moving inside its bush. The steering coupling has been replaced with a modern equivalent.

I "refurbished" the rack a few years ago with a new rack bush on the end away from the pinion, and set up the pinion and steering arms settings as best I could. I am not sure what can get replaced on a rack if it is sent away for a professional job - it might come back in the same state!

Incidentally, I believe the MOT failure limits on rack and pinion steering used to be half an inch at the steering wheel, and up to 1.5 inches for older recirculating ball or worm and peg steering (showing my age now) :)

Dave.
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PostPost by: Tonyw » Sun Jan 02, 2011 10:11 am

David,

You should have neither pre load or end float on your front wheel bearings it should be neutral when you insert the spit pin in the castellated nut go for one hole on the tight side. If you have some slight play in the rack and pinion with the wheels straight ahead try removing one shim from the pre load plate which is under spring tension. Rack and pinions spend most of their lives in the straight ahead position so it will probably feel a bit looser in this position that when on partial or full lock.

Hope this is of some use.

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PostPost by: andyelan » Sun Jan 02, 2011 2:10 pm

Hi again David

Are you sure youve actually got play in the rack as there are a couple of thing which give the impression of play without there actually being any.

The slipper which pushes the rack into mesh with the pinion will move side to side a little in its housing as it's dragged one way then the other by the rack. Although this can be felt at the steering wheel (and heard) it doesn't affect the movement of the rack and it's not free play. If you want to check this out put a clock against the road wheel and see if you can detect movement while the steering wheel is turned slightly

The other item which can give the impression of play is movement in the top steering column bush. Even new bushes have a lot of crearance in them and what is often thought of a play is actually the steering wheel moving bodily up and down or left and right within the bush

Just a couple of thoughts

Regards
Andy
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PostPost by: gjz30075 » Sun Jan 02, 2011 7:20 pm

On an Elan, the steering shaft is two pieces, the ends of which are somewhat 'D' shaped and the 'D's mesh together, then clamped. This is also a source of play. Same arrangement for a +2?

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PostPost by: david.g.chapman » Mon Jan 03, 2011 10:14 am

Thanks again, all of you. All good ideas.

Andy, I tried clocking the front wheels as you suggested with my dial gauge, and both front wheels are moving before you hear the soft clonk, which seems to be coming from the rack. There really is no play. Movement in the rack slipper could very well be the cause - nice one :D

I have the early one piece steering column, and have sourced some replacement felt bushes, and fitted those to eliminate play in the column.

I will also try less float in the front wheel bearings in future. These bearings are the same as those in the mark 1 Ford Capri I used to own, and you had to pre-load those with a torque spanner and then back off a bit. As the designers of the Elan anticipated some extra heating from the front discs, this may have explained the loose setting for the bearings in the manual. I will go for a little bit of end float (1 thou) and see what happens. By the time the wheels have turned a bit the running settings may very well end up "correct" anyway.

Dave.
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