SteveDown
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| posted on 2/7/15 at 09:15 PM |
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Failed IVA - steering not returning to centre.
Hi all,
My car failed IVA because the steering won't make any attempt at returning to centre. Since the test I've tried to toe the wheels out,
adjusted the suspension height so the steering rods are level, and increased the tyre pressure to 35psi. Despite a number of adjustments and
subsequent testing there's been no change and the steering remains in the position to which it is pointed.
I'm unable to adjust the camber/caster so my options are rather limited.
This is the only problem I need to resolve for a retest, however, after a couple of frustrating weeks trying to fix it, I feel that only an all
powerful wizard it going to be able to sort it out. :-(
Thanks,
Steve
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big_wasa
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| posted on 2/7/15 at 09:23 PM |
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No you just need new front top wish bones with at least 7 deg of castor. What car is it ?
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JC
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| posted on 2/7/15 at 09:38 PM |
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Silly question - have you got the top wishbones on the correct side? Try swapping them?
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coozer
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| posted on 2/7/15 at 09:38 PM |
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Where are you? Someone close should be able to help...
1972 V8 Jago
1980 Z750
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Dave Bailey
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| posted on 2/7/15 at 09:40 PM |
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I know this may be a sticky plaster but what friction is in your steering... I have helped my self centering by replacing the std Sierra column
plastic bearing with a proper bearing vastly improving the steering feel, drag and stiffness....
Dave B
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HowardB
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| posted on 3/7/15 at 05:45 AM |
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quote:
Originally posted by Dave Bailey
I know this may be a sticky plaster but what friction is in your steering... I have helped my self centering by replacing the std Sierra column
plastic bearing with a proper bearing vastly improving the steering feel, drag and stiffness....
Dave B
Dave,
do you remember the bearing number that you used?
thanks
HowardB
Howard
Fisher Fury was 2000 Zetec - now a 1600 (it Lives again  and goes zoom)
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Dave Bailey
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| posted on 3/7/15 at 06:23 AM |
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I will have a look later today....
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Dave Bailey
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| posted on 3/7/15 at 06:33 AM |
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Simply bearings...
Products Each Total
1 x SBPFL205 Oval 2 Bolt Pressed Steel Bearing Housing with 25mm insert
Option's £7.74 £7.74
The plastic triangular core bush presses into the bearing. The bearing outer race is spherical which allows the bearing to align with the shaft and
the angle of the bulkhead...
Dave B
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SteveDown
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| posted on 3/7/15 at 06:49 AM |
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I've built a Series 2 Lotus 11, this is with an original spec chassis and suspension components. I'm not sure what car the top links are
taken from, I'll find out. They were also used on the Lotus MK14, and I suspect numerous other Lotus cars from the 1950's/60's. The
roll bar hooks into it and making something to replace it is way beyond my capabilities.
I'm located in Welwyn, but taking the car to anyone is problematic.
[Edited on 3/7/15 by SteveDown]
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CC Cyclone
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| posted on 3/7/15 at 09:34 AM |
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Take the track control arm out at both sides and check for free movement / pivot of the upright, it it is all new there may be some resistance to
overcome that is causing problems. I had it, took mine apart reassembled and torqued up again and all was fine, except i did discover that my new
balljoints were causing a problem and were junk. Replaced them with good quality versions and all was fine.
Castor is the key to it though as has been said.
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smart51
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| posted on 3/7/15 at 12:29 PM |
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I had this problem on my trike and I dod a lot of work to try and fix it before it went to MSVA. My advice is not to cheat to get it through the test
but to fix it properly. Self centring is an important part of steering feel. A lack of self centring gives a lack of feedback and confidence in the
car.
As said above, I'd check for friction in all the moving parts. The self centring force generated by the wheels has to overcome the friction to
move. Light weight cars don't make much force so need minimal friction to work properly.
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MikeRJ
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| posted on 3/7/15 at 05:09 PM |
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quote:
Originally posted by SteveDown
I've built a Series 2 Lotus 11, this is with an original spec chassis and suspension components. I'm not sure what car the top links are
taken from, I'll find out. They were also used on the Lotus MK14, and I suspect numerous other Lotus cars from the 1950's/60's. The
roll bar hooks into it and making something to replace it is way beyond my capabilities.
I'm located in Welwyn, but taking the car to anyone is problematic.
[Edited on 3/7/15 by SteveDown]
Are you using a genuine Lotus 11 steering rack, and if so has it been "reconditioned"? I put that in quotes as there are some
horrendously bad reconditioning companies whose idea of reconditioning is to fit new gaiters, wind up the rack preload and dunk it in a vat of black
paint. You end up with a rack so tight that car is almost undriveable.
If you jack up the front wheels does the steering still feel tight, or is it free enough to steer with one finger on the wheel?
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avagolen
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| posted on 3/7/15 at 06:14 PM |
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Pre IVA I jacked my car up, placed axle stands under the front wishbones and sat in it.
Then for quit a while I just wound the steering from side to side to 'exercise' all of the
New components. I could do it easily with one finger after a while.
The Answer for everything, but never the last word....
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mistergrumpy
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| posted on 3/7/15 at 08:55 PM |
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I second everything that's been said. I found that a good clean and oil of the steering rack helped a lot along with a bit more air in the tyres
than usual.
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SteveDown
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| posted on 4/7/15 at 12:06 AM |
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The steering rack is from a Mini (it's lighter) rather than a Morris Minor and has been professionally shortened. It's in tip top
condition and the steering operation is super light with very little effort required.
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907
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| posted on 4/7/15 at 05:47 AM |
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That Mr Wasa in reply number one is a clever chap.
Those that suggest that making sure everything moves freely do no harm at all.
Screwing in loads of this or that and pumping tyres to non usable settings isn't the road to happy motoring.
I made my bones wrong, bit the bullet, and made some more.
Paul G
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MikeRJ
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| posted on 4/7/15 at 12:46 PM |
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quote:
Originally posted by SteveDown
The steering rack is from a Mini (it's lighter) rather than a Morris Minor and has been professionally shortened. It's in tip top
condition and the steering operation is super light with very little effort required.
That suggests that you may be starting with very little castor, which won't help matters at all. Have you measured the castor to ensure
it's correct for whatever a Lotus 11 should have?
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SteveDown
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| posted on 4/7/15 at 02:07 PM |
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I don't know how to measure the caster, visually however, it appears to have none. The top ball joint is sitting directly above the trunnion.
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blakep82
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| posted on 4/7/15 at 02:17 PM |
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Castor is measured by making a line through the centres of the top and bottom ball joints, the angle of that line away from vertical is the castor
angle
As said, swap your top wishbones over first of all, that may fix it. They may not be symetrical
[Edited on 4/7/15 by blakep82]
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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SteveDown
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| posted on 4/7/15 at 02:57 PM |
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Thanks for the diagram, I'll go measure it. I've posted a couple suspension pics in my Photo Archive.
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907
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| posted on 4/7/15 at 03:38 PM |
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quote:
Originally posted by SteveDown
I don't know how to measure the caster, visually however, it appears to have none. The top ball joint is sitting directly above the trunnion.
I know this is a 7 and yours is an 11 but looking from directly above caster looks like this.
 
Rescued attachment bone-fitted-2s.jpg
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SteveDown
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| posted on 4/7/15 at 03:43 PM |
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Oh wow, that's way more than I have. I've just been out to the garage and hung a plumb line. There is some caster there, but's a
tiny amount in comparison to yours.
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cs3tcr
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| posted on 7/7/15 at 10:09 PM |
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Steve,
I had a quick look at the drawings I have, and both the Seven S1 and Eleven S2 should have 5 degrees of caster. But, you might have less if the
swaybar has pulled the upper link forward (it happens under bump and droop). I would have a look at how tight you've compressed the bushings
that the swaybar passes through on the upper link. Also, see if there is any binding in the steering column, you may have to rotate the rack a bit
to allow the column U-joints to work freely, provided you have the original type column with it going between the pedals etc.
Rod
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SteveDown
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| posted on 8/7/15 at 11:33 AM |
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Hi Rod,
The steering UJ's are free of any binding, as you correctly stated, twisting the rack up slightly resolves this.
I'll loosen the sway bar tonight and see if I can get some movement out of it.
Ta,
Steve
BTW, your car looks very nice.
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SteveDown
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| posted on 12/7/15 at 08:25 AM |
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I tested the car yesterday, still no change unfortunately. I feel that passing IVA is going to be impossible and I have a very expensive pile of scrap
metal sitting in my garage.
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