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I have recently replaced my shocks and bushes, so I need to redo my alignment.

I have the information for the front suspension, but not sure about adjusting the rear toe.

I have 3 shim washers on the inner side of the radius arm at the front mounting and 1 shim washer on the outer side, as per the diagram in Page 4 of Section DC in the manual.

The shim washers are 1-1.1mm.

Anyone can advise what is the effect of shifting 1 shim washer from the inside to the outside, and shifting the shim washer outside to the inside of the front mount. Part 37 in the picture.

The spacer plate is now only available in 0.9mm and 1.6mm width. Part 27 in the picture.

What will be the effect if I add the shim plate as per the diagram.

It would be easier if I have a estimated effect as removing the rear arm can be quite a chore.

Thank you

Rear Suspension Alignment.pdf

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Basically messing around trying to guesstimate your GEO with calculations of 1mm here to 1 mm there will just put you in a world of hurt.. you can end up with your rear end sort of tracked but on the

Hi hspeck, Using a simple geometry calculation could help you with this if no-one knows. If the rear radius arm measures say 600mm from its front pivot to the centre of the drive shaft, a 10

Hi hspeck, Most alignment centres don't seem to want to get involved beyond adjusting threaded rods and lock nuts. It's only the performance specialists that will, and probably should, engag

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Part 27 is available as a split piece - had you seen that?.  So all you have to do is loosen the two outside nuts and slide them in (still a chore on the header side as the heat shields have to come out I think).

Have  you measured the toe yet?

I think I could do the math and figure it out with some careful measurements, surely some one has measured, installed and re measured.  I am surprised the info is not in the manual but maybe there are too many variables.  Rubber bushings will never measure the same twice. 

That said dont worry about perfect.  Everything moves around once you drive any way :-)  

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21 minutes ago, Erikl said:

Part 27 is available as a split piece - had you seen that?.  So all you have to do is loosen the two outside nuts and slide them in (still a chore on the header side as the heat shields have to come out I think).

Have  you measured the toe yet?

I think I could do the math and figure it out with some careful measurements, surely some one has measured, installed and re measured.  I am surprised the info is not in the manual but maybe there are too many variables.  Rubber bushings will never measure the same twice. 

That said dont worry about perfect.  Everything moves around once you drive any way :-)  

Yes, Part 27 can be slipped in.

There was information for front toe adjustment, which states that 1.5mm increase toe by approximately 1°, hence I could more or less calculate the width of shims needed. 

The rear I can only do on a hoist, which I need to "borrow" from a friend who owns a workshop, hence I cannot afford to take up too much time on the hoist. 

Really appreciate if someone can give me an estimate.

Thank you.

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On 05/11/2020 at 07:18, hspeck said:

What will be the effect if I add the shim plate as per the diagram.

Hi hspeck,

Using a simple geometry calculation could help you with this if no-one knows.

If the rear radius arm measures say 600mm from its front pivot to the centre of the drive shaft, a 10.5mm thick shim would be required to move the toe 1 degree.

If the rear radius arm measures say 700mm from its front pivot to the centre of the drive shaft, a 12.2mm thick shim would be required to move the toe 1 degree.

ie Radius arm length X 2 X 3.142 the divided by 360 will give you the theoretical shim thickness per degree.

Just apply your radius arm measurement to the formula above.

Considering the figures, it looks like 1mm and 1.5mm shims will give a very fine adjustment.

Just a guide, just trying to help.

Andy.

 

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Hi hspeck,

Having just measured my radius arms, they appear to be around 550mm long from the front pivot to the centre of the drive shaft. (Rough measurement as my car is not jacked up)

So, following on from my previous post, 550x2x3.142/360 = 9.6mm per degree.

So, a 1mm shim would alter the rear toe by around 0.1 degree and a 1.5mm shim would alter the toe by 0.15 degrees.

All based on the maths but should be close to real world findings.

Andy.

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I have wondered about that.  the width of the washer almost seems too hard to quantify - barely within the error of an alignment machine - Could you measure that at all using string?  I could not - but that is not saying much.

That said I recently installed spherical bearings at the rear suspension pivot we are talking about.  I measured fairly carefully to get the arm in the same position as it was with the stock bushing.

I initially installed one side and drove it around for a while.  I think I can visually see that the toe is off a little in the rear on the one side. Also have a very slight pull, but I changed a bunch of stuff in the suspension so that could be a number of things. 

Interesting and timely discussion.

@CHANGES

have you ever changed rear toe by one washer and quantified the toe change/mm at the pivot?

 

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20 hours ago, AndyPG said:

Hi hspeck,

Having just measured my radius arms, they appear to be around 550mm long from the front pivot to the centre of the drive shaft. (Rough measurement as my car is not jacked up)

So, following on from my previous post, 550x2x3.142/360 = 9.6mm per degree.

So, a 1mm shim would alter the rear toe by around 0.1 degree and a 1.5mm shim would alter the toe by 0.15 degrees.

All based on the maths but should be close to real world findings.

Andy.

Thanks Andy, I did kind of realised that shifting the shim washers from inside to outside will have minimum effect, but that was the recommendation in the manual. When i removed the radius arm to fit the bushes, there were 2 pieces of shim plates, 1 1.6mm and another 6mm on the driver side, and only 1 6mm plate on the passenger side. 

But again, the recommended spec is not a big value. Can't remember exactly as I do not have the manual with me now. 

But your calculations will definitely help. 

Thank you. 

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16 hours ago, CHANGES said:

Basically messing around trying to guesstimate your GEO with calculations of 1mm here to 1 mm there will just put you in a world of hurt.. you can end up with your rear end sort of tracked but on the wrong thrust angle ..    I have always said you should get these Esprit set up professionally . They will be able to set up the ride heights with corner balancing then track the Esprit to the desired GEO .  There is an art to doing this on an Esprit and an order , otherwise you end up chasing yourself . They will do this by setting the cambers, then shifting the washers or inserting the shim plates as used on the later models ... The split shim plates are so much easier to use and i always convert any early models i do to that spec..   I will be covering that topic in the OOPS, Crash Bang thread,  when the new suspension goes into that Esprit..   As it happens Its very close to the same spec as @hspeck's Esprit .. The suspension kit is the same i have supplied for both. I think the only difference between the two is tyre size and wheel type etc. 

What owners do not seem to fully grasp is how good these Esprit are when they are set up correct. very few have their Geo regularly checked and adjusted with wear .. As a result they never perform or feel as they should..  

They should be all set up on a Hunter or equivalent laser alignment equipment by qualified technician ...  This will cost money but well worth it when done correct ...  Any alternative will be a compromise ...  I specify with all the kits i sell that the GEO and balancing should be professionally addressed once  fitted. 

IMG_20180405_105457005_HDR.jpg  

Doing  it right first time , works out cheaper in the long run ...     

Hi Dave, I would definitely do the corner weight balancing and getting the alignment professionally set, but there is only 1 guy doing corner weight balancing in my country, and my slot is in January 2021..! 

In the mean time i would like to drive my car, and the shop with the Hunter  alignment machine wants only to set the front camber and toe, as well as the rear camber. They do not want to help to set the front caster and rear toe, hence i have to try to set it myself as close to spec as required. 

Hence this thread.. 

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34 minutes ago, hspeck said:

the shop with the Hunter  alignment machine wants only to set the front camber and toe, as well as the rear camber. They do not want to help to set the front caster and rear toe

That is a shame but not a surprise at all.  

Maybe the best option is to put the washers back as you found them and check the rear toe with string.  If its close you should be fine to drive it for a month.

FWIW I was able to disassemble and re-assemble my rear pivot parts from jack stands, not a lift.  Not fun but possible.

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1 hour ago, hspeck said:

They do not want to help to set the front caster and rear toe, hence i have to try to set it myself as close to spec as required. 

Hi hspeck,

Most alignment centres don't seem to want to get involved beyond adjusting threaded rods and lock nuts.

It's only the performance specialists that will, and probably should, engage with the Esprit, as Dave has mentioned.

I don't want to go head to head with anyone, each to their own, but I am quite happy aligning my Esprit myself at home with basic equipment.

IMHO, I think it is an achievable, and interesting task if you know what you're doing.

You can then have a check done at your local shop, if you trust them.

Andy.

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On 07/11/2020 at 20:29, Erikl said:

That is a shame but not a surprise at all.  

Maybe the best option is to put the washers back as you found them and check the rear toe with string.  If its close you should be fine to drive it for a month.

FWIW I was able to disassemble and re-assemble my rear pivot parts from jack stands, not a lift.  Not fun but possible.

I have set them back to specs. Although the car was within the alignment specs before i replaced the bushes, i found that the shims were not correctly inserted. Eg, there were shim plates on each side of the ball joint at the front wishbone. The manual states that the shim plate should be diagonally across the shim washers, but it was not. 

So i thought it was best i reset to spec

On 07/11/2020 at 21:15, AndyPG said:

Hi hspeck,

Most alignment centres don't seem to want to get involved beyond adjusting threaded rods and lock nuts.

It's only the performance specialists that will, and probably should, engage with the Esprit, as Dave has mentioned.

I don't want to go head to head with anyone, each to their own, but I am quite happy aligning my Esprit myself at home with basic equipment.

IMHO, I think it is an achievable, and interesting task if you know what you're doing.

You can then have a check done at your local shop, if you trust them.

Andy.

As I have the adjustable wishbone at the front and adjustable link at the rear, setting the camber is relatively easy. 

I will however have to first set the caster before i send to the shop with the hunter alignment machine. They will set the camber and toe in the front and the camber at the rear. After which i will have to set the rear toe myself. 

Hopefully i am able to get it close to spec for the time being.. 

 

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5 hours ago, hspeck said:

i found that the shims were not correctly inserted. Eg, there were shim plates on each side of the ball joint at the front wishbone

Hi hspeck,

I tried searching for a recent in-depth discussion on these shims to send you but I can't find it at the moment.

From memory, there can be shims on both sides of the top ball joint. I seem to recall that there should be a total of 6 or 10mm??? (can't remember off hand) of shims present between the wish bones. And depending on requirements, they are placed both sides of the ball joint to achieve the correct caster while maintaining the correct space between the wish bones.

Needs looking into as your manual might be a little vague.

Andy.

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On 06/11/2020 at 23:37, AndyPG said:

Hi hspeck,

Having just measured my radius arms, they appear to be around 550mm long from the front pivot to the centre of the drive shaft. (Rough measurement as my car is not jacked up)

So, following on from my previous post, 550x2x3.142/360 = 9.6mm per degree.

So, a 1mm shim would alter the rear toe by around 0.1 degree and a 1.5mm shim would alter the toe by 0.15 degrees.

All based on the maths but should be close to real world findings.

Andy.

Finally had time to look at the original specs...

the rear toe in is 1.5mm each side +/- 0.5mm, which works out to be 0­°8' to 0°15' on my 18" wheels... so the adjustment should be very minimal, hence the 1.1mm washer.. I think .. :)

 

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9 minutes ago, AndyPG said:

Hi hspeck,

I tried searching for a recent in-depth discussion on these shims to send you but I can't find it at the moment.

From memory, there can be shims on both sides of the top ball joint. I seem to recall that there should be a total of 6 or 10mm??? (can't remember off hand) of shims present between the wish bones. And depending on requirements, they are placed both sides of the ball joint to achieve the correct caster while maintaining the correct space between the wish bones.

Needs looking into as your manual might be a little vague.

Andy.

Hi Andy,

minimum is 6mm

this is the instructions in the manual for the front suspension-

"Provision is made for castor adjustment by the distribution of shim washers (total thickness 6 mm) between the front and rear of the chassis at the top wishbone pivot stud. In all cases, a 1.5 mm shim washer must be retained  between the front wishbone arm and chassis to ensure adequate clearance between arm and chassis under extreme conditions.

If the correct castor cannot be achieved by distribution of these shims, it is permissible to fit an additional 1. 5 or 3.O mm shim washer between arm and chassis TOGETHER with a similar thickness shim plate between THE OTHER wishbone arm and top ball joint. i.e. if an additional shim is fitted between the front wishbone arm and chassis, a corresponding shim plate is fitted between the rear wishbone arm and ball joint."

the manual states that "In all cases, a 1.5 mm shim washer must be retained  between the front wishbone arm and chassis to ensure adequate clearance between arm and chassis under extreme conditions", I take it to mean that there must only be a 1.5mm shim washer between the front of the wishbone and chassis.. and I may be wrong, but I will start with that and try to get the correct front caster..

in the original configuration before i replaced the bushes, there was no extra shim washers on the front of the wishbone towards the front of the car, only the 1.5mm washer, so there should not be another shim plate across at the ball joint, or at least that's how i feel it should be..

i have attached the diagram from the manual

01.Service Notes Content-CD 94.pdf

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3 hours ago, hspeck said:

in the original configuration before i replaced the bushes, there was no extra shim washers on the front of the wishbone towards the front of the car, only the 1.5mm washer, so there should not be another shim plate across at the ball joint, or at least that's how i feel it should be..

You're quite right.

Just found the thread I was looking for, and participated in. Seems my memory is failing.

When I checked and corrected my geometry last summer, all was fine apart from front toe and caster.

I think I found shim plates both sides of my ball joints too.

Come to think of it, I've read several threads reporting the same.

Sometimes makes me wonder if some Esprits came out of the factory like this. Perish the thought.

Andy.

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Part no. 27 should not require removal or swapping under normal circumstances unless you have chassis damage & repair from a heavy accident etc. The shims are used to obtain a rough toe-in adjustment, then the shims (washers) part. no. 37 are moved around to obtain a final toe-in adjustment. 

Lotus lists a total of 10 shims for the rear suspension i.e 5 pieces for each side. Should you have all 5 shims either under the radius arm, or beneath the lock-nut and you find that the correct toe-in values cannot be achieved, then only would you change part no. 27 to obtain the rough toe-in required. Part no. 27 is only changed as a last resort.

IIRC more shims (part no. 37) between the radius arm and snubber washer increases toe-in and vice versa for fewer shims.

 

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33 minutes ago, ekwan said:

Part no. 27 should not require removal or swapping under normal circumstances unless you have chassis damage & repair from a heavy accident etc. The shims are used to obtain a rough toe-in adjustment, then the shims (washers) part. no. 37 are moved around to obtain a final toe-in adjustment. 

Lotus lists a total of 10 shims for the rear suspension i.e 5 pieces for each side. Should you have all 5 shims either under the radius arm, or beneath the lock-nut and you find that the correct toe-in values cannot be achieved, then only would you change part no. 27 to obtain the rough toe-in required. Part no. 27 is only changed as a last resort.

IIRC more shims (part no. 37) between the radius arm and snubber washer increases toe-in and vice versa for fewer shims.

 

Yes, that's what I thought too, as the toe in spec is very minimal.

From what I understand, the shim plates should only be used if we are not able to achieve the correct toe in by moving the shim washers.

the manual states that "Rear wheel alignment is adjusted by transferring shim washers between the inner and outer sides of the radius arm at its front mounting. IF correct adjustment cannot be obtained by transference of the three 1mm shim washers, spacer plates MAY BE fitted between the radius arm mounting and the chassis."

hence I am resetting it back to specs, without the shim plates

will send it to a alignment machine once i get it done

thanks

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You don’t move anything until you have measured your suspension geometry beforehand. 

............not unless you enjoy doing work for nil benefit.

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56 minutes ago, ekwan said:

You don’t move anything until you have measured your suspension geometry beforehand. 

............not unless you enjoy doing work for nil benefit.

I moved everything when I replaced all the bushes and the suspension

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31 minutes ago, ekwan said:

Yes. But you replace everything as you found them, measure then adjust as necessary instead of shooting at unknown targets in the dark.

Nope, they were not placed in accordance to the manual when I removed them..

as i have stated wrt the front castor settings..

i am not sure if I am right or wrong in my interpretation of the manual, but I would like to put everything back to spec and then do the adjustment accordingly 

On 09/11/2020 at 17:24, hspeck said:

 

in the original configuration before i replaced the bushes, there was no extra shim washers on the front of the wishbone towards the front of the car, only the 1.5mm washer, so there should not be another shim plate across at the ball joint, or at least that's how i feel it should be..

i have attached the diagram from the manual

01.Service Notes Content-CD 94.pdf 58.86 kB · 3 downloads

 

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2 hours ago, hspeck said:

Nope, they were not placed in accordance to the manual when I removed them..

as i have stated wrt the front castor settings..

i am not sure if I am right or wrong in my interpretation of the manual, but I would like to put everything back to spec and then do the adjustment accordingly 

 

Errrrmmmm............On the front, you must have 1.5mm shim on the front and rear of the upper wishbones. That's now 3mm of shims (1.5+1.5) + the 3mm gives a total of 6mm.

If you need to exceed this 6mm total to correct the caster, then you need the additional shim at the ball joint of the same additional thickness beyond the 6mm I believe the instructions will be found on the workshop manual on the page preceding the diagram that you scanned.

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On 12/11/2020 at 17:03, ekwan said:

Errrrmmmm............On the front, you must have 1.5mm shim on the front and rear of the upper wishbones. That's now 3mm of shims (1.5+1.5) + the 3mm gives a total of 6mm.

If you need to exceed this 6mm total to correct the caster, then you need the additional shim at the ball joint of the same additional thickness beyond the 6mm I believe the instructions will be found on the workshop manual on the page preceding the diagram that you scanned.

This I do understand, but not the previous shop i went to for alignment. they placed shim plates on both sides at the ball joint but they only added 1 single 3mm shim washer at the front end of the upper wishbones 

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6 hours ago, hspeck said:

This I do understand, but not the previous shop i went to for alignment. they placed shim plates on both sides at the ball joint but they only added 1 single 3mm shim washer at the front end of the upper wishbones 

Hi HsPeck,

Seeing as you have discovered shims on both sides of the front upper ball joint, I agree with your approach.

Andy.

 

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