Lotus Elan

More steering lock on one side

PostPost by: rgh0 » Thu Mar 31, 2016 8:51 am

Most replacement chassis I have seen are drilled for both LH and RH drive rack mounting and the mounts should fit against the flanges rack so you may have the mounts in the wrong holes

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PostPost by: EPC 394J » Thu Mar 31, 2016 9:48 am

Thanks very much indeed for all your observations. All very much appreciated!

I've been away for a few days, but will take some better pictures as soon as I can.

The chassis is a Lotus original, that's about 30 years old, but recently blasted and powder coated, so hopefully the holes (at least!) are correct?
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PostPost by: EPC 394J » Thu Mar 31, 2016 7:17 pm

So, bearing in mind this is a Lotus Plus 2 chassis, and I presume the bracket holes are in the right place, what, if anything, is wrong with the mounting of this steering rack?
image.jpg and
Driver's side

image.jpg and
Near side

image.jpg and
Underside of near side

There do appear to be two chassis holes, outboard of the ones used on the near side.

How crucial is it, that the brackets and flanges actually abut each other on both sides?

These are Spyder brackets. Are they designed for Spyder chassis, and subtly different?? I'm guessing not, because in any event, the same rack would have to be used?

In any event, it does appear that the 'starboard' (ie RHD???) holes may have been utilised on both sides? Or is the rule, outboard holes on the near side, and inboard holes on the pinion end???? :?:

Of course, this won't solve my lock-lock problem, but just want to know how much I'll need to change to get it absolutely right!

Very many thanks

Andy
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PostPost by: fattogatto » Thu Mar 31, 2016 10:07 pm

The way your rack is located there is nothing stopping it from moving to the near-side. On my S3 the off-side (labeled near-side image in your post) mounting bracket has two ears that extend to grab the raised flange (to the right in your photo) when bolted in. This gives positive location and keeps the rack from migrating.

You might try turning the bracket around and seeing if it will butt up against the flange. That would keep the rack positioned securely.
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PostPost by: fatboyoz » Thu Mar 31, 2016 11:12 pm

Andy,
Judging by the relationship between the pinion housing and the rack mounting platform, your rack is correctly positioned. The solid mounts also appear to be correctly located. Have you checked them for tightness?
My guess for the difference in the amount of steering turns left to right would be incorrectly adjusted tie rod ends.
On closer inspection of your first set of photo's, it looks like your tie rod ends, and extensions, are longer on the left than the right. This means that for the straight ahead position, the rack centre would be displaced to the right of centre. The r/h limit stop is actually on the l/h side of the rack, and it would also be displaced to the right in the straight ahead position. This would account for the fact that you can feel the solid contact of the stop at the full right hand deflection at only one full turn of the wheel. It would also account for why your l/h wheel hits the sway bar (arb) before hitting the l/ h stop and the increased steering wheel deflection.
Cheers,
Colin.

quote="EPC 394J"]When I say a garage rebuilt my steering, this is what I mean:
image.jpg
image.jpg
image.jpg
image.jpg

Any clues?

Many thanks

Andy[/quote]
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PostPost by: Quart Meg Miles » Thu Mar 31, 2016 11:13 pm

I agree with Charlie. You need to turn the nearside (real LH) bracket round and bolt it into the other set of holes to support the rack.

You also need to fit the missing spacer in the rack. I had the same problem thirty years ago on my Elan (tyre rubbing on the roll bar) and sawed a spacer in two halves so I could fit it over the rack end without disassembling everything, just slipped the bellows off to expose the rack. I think I have a spire clip over the two halves.
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PostPost by: elj221c » Sun Apr 03, 2016 12:17 pm

Andy,
To me, your rack looks like it is too far to the left. (sitting in the driving seat)
This was how mine looked,although not a +2, the rack and mounts are the same.
I mounted the rack in the holes where Spyder had wired the shims and centralised the rack between the mounts as you can see in the pictures below.
6.jpg and

img005.jpg and
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PostPost by: EPC 394J » Sun Apr 03, 2016 6:42 pm

Roy

That's really helpful, thank you. It actually would account for two of my observations. Firstly that, My rack mounts occupy the same hole pairs, in the chassis as yours. In fact, I don't think it would be possible to fit the rack mounts in any other configuration, as the rack flanges, then obstruct the chassis holes! But secondly, it would appear, I may be able to reduce (fractionally) my steering wheel offset. So all good stuff, thanks.

Unfortunately, I work away from home, and can't spend much time with the car at the moment. (Amongst the myriad of other domestic tasks!) So I'm trying to 'short cut' the diagnostic process, rather than doing what I really need to do, which is get the spanners out! But I think I 'may' be making a little progress?

With the road wheels removed, it seems I do have 2.7 turns of the steering wheel from lock to lock. I hear a very metallic 'tap' at the full range to the right, and a very slightly different sound at full range to the left. Far more steering wheel movement to the left, (as I have explained previously) but no obvious contact between anything on the vertical link, and the chassis. So maybe both spacers are indeed fitted. Perhaps a reasonably simple fix then, even for me???

I don't imagine this is significant, but just in case, I have 25cm of track rod on the driver's side, and 23.5cm on the near side? I guess this isn't unusual? (Actually seems to tie in with Roy's observation about the rack's position?)

Couple of pictures, on the off chance some of you incredibly knowledgeable chaps might notice anything?
image.jpg and
Driver's side

image.jpg and
Near side
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PostPost by: rgh0 » Mon Apr 04, 2016 11:14 am

The original rack clamps fitted up against the flanges to positively locate the rack. If Spyder designed these new solid clamps they did not understand the design intent of the flanges unfortunately.

Photos of the rack on my PLus 2 - pardon the overspray from the recent paint job that needs cleaning up before final assembly :)

cheers
Rohan

img_1232.jpg and


img_1231.jpg and
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PostPost by: elj221c » Mon Apr 04, 2016 12:01 pm

Rohan,

The Spyder clamps hold the rack in position by clamping. The OEM clamps are of course rubber so their movement needs restricting. The holes in the chassis need to accomodate both types.

To be clear, the rack has never moved in service. I suppose if one was worried about that happening split spacers could be made up to fill the gap.

On the race cars I worked on, the rack tubes didn't have flanges and were just clamped so I don't think it is an issue. Not a great picture but gives you the idea....

unclothed-coldwell.-june-99.1.jpg and
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PostPost by: rgh0 » Mon Apr 04, 2016 12:21 pm

I am sure it can be done but I hope Spyder did the detail calculation of the collapsing strength of the tube and the friction required to guarantee the column never moved and provided that detail of clamp tolerances and rack tube tolerances and bolt torques to every buyer of their clamps.

Call me a cautious cynic but personally I prefer to have my rack positively located and not to rely on friction and 4 bolts staying at the correct tension especially for a road car where the rack is buried under the radiator and that does not get checked before every race. it is not that much more expensive to make the rack clamps a few mm wider to pick up the rack flanges??

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PostPost by: fattogatto » Mon Apr 04, 2016 1:22 pm

My S3 has one of the clamps as shown above that has two "L" shaped extensions. The other clamp that goes next to the steering column connection does not have these extensions. On the off-side, if I bolt the clamp with these extensions into the proper holes these extensions solidly fit over the flange on the rack providing positive location. The near-side clamp locates by butting up against the flange. In the pictures above both of the clamps have these "L" shaped extensions but they seem superfluous in both applications. However, in the upper photo, if you move the clamp to the exposed holes these extensions will fit nicely over the flange, providing a more positive location.

And, every race car I have owned (about 24 at last count from S-2000 to F1 Shadow) have positive rack locating systems which use pinch blocks as well. The last thing you want is for a rack to migrate or move with just a tap from a competitor.
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PostPost by: elj221c » Tue Apr 05, 2016 9:17 am

Well, Andy,

There you have it. Charlie and Rohan have much more experience.

Position your rack and use spacers from the clamps to the rack flanges.

Job's a good'un!
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PostPost by: Matt Elan » Tue Apr 05, 2016 8:19 pm

Ignoring the rack fixings for the moment, I still think its the centralisation of the rack that's the issue. Looking at the problem logically, its simple geometry:
1. You've got the standard 2.7 turns lock to lock so the lock limiting spacers must be in place.
2. If that is the case, the only way the rack can apparently turn a wheel further on one side is if the combined length of the tie rod, rack adaptor and track rod end on that side is longer.
3. Any difference in length will be created by how far the adaptor is screwed into the tie rod, and the track rod / ball joint is screwed into the adaptor. Note that all three elements (tie rod, adaptor, ball jount) are the same on each side so the overall assembly should be pretty much of identical length.

So if you do what I suggested in my previous post (centralise the steering rack at 1.35 turns from either lock, both wheels should be at the same angle - i.e straight ahead. If the wheels are not straight ahead, then that's the problem, and you can try to bring them to the straight ahead position by adjusting the track rod ends and extensions. As you've got a difference of 1.5 cm of track rod length side to side, this may be enough to indicate that's the problem. I've just measured mine - I've centralised my rack but haven't set it precisely, and the side to side length of the extension and track rod end is about the same.
HTHs
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PostPost by: EPC 394J » Wed Apr 06, 2016 7:31 pm

Hi Matt

Really appreciate your, (and everyone else's) thoughts. It's all helping me to formulate a plan.

I'm absolutely thinking along the same lines as you. I have two days at home now. Amidst all the domestics, I hope to get a little time to take a good look at what's required.

I don't think it's possible to abut the rack flanges to the mounts without the use of additional spacers, so I think I will go with Roy's plan, to simply centralise my rack and accept any flange-mount gap. (This small movement of the rack would tend to equalise my tie-rod lengths.) The only reason I can imagine this was not done originally, is possibly due to interference between the steering coupling and radiator bottom hose? I will need to raise the radiator for sure!

Then it's a case of disconnecting the two ends. Centralising my rack, re-connecting and tracking, with toe-in?

The only additional thing I may do, is slide the gaitors (bellows) back, to see if there are lock spacers fitted at both ends? But lock to lock, should confirm that anyway?

Hopefully that sounds like a plan?

Many thanks.

Andy

PS: anyone got a picture of the stamps on a Lotus original chassis, that show the required rack shim sizes? Just in case I can read them on mine?
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