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Esprit S1 rear SPAX camber issue. - Suspension/Brakes/Wheels/Hubs/Steering/Geo - TLF - Totally Lotus Jump to content


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Esprit S1 rear SPAX camber issue.


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I have an issue with aligning in this car.  Please forgive inaccurate or wrong terms, I am pretty green to this stuff.  I have no documentation for the history of this car, other than it went through a restoration in the early 2000s.

The camber is bad on the rear right corner.  (US car)

I took it to a local shop that has worked on esprits before.  They had an alignment attempt, but at the alignment place they said there is not enough adjustment in the coilover setup to align the car.

The coilovers (or dampers?) are Spax, not sure which type.  The Left side is adjusted higher, maybe this is normal? The right side is adjusted lower, and this is the wheel that has a lot of negative camber. It looks like someone adjusted it higher in the attempt to align (judging by the cleaner thread) but couldn't.   I was advised to either lower the front of the car, or come up with a different coilover set up for the rear.  They asked their parts department, but they helpfully had no ideas for any replacement coilovers.  I am thinking these coilovers are indeed correct for this car, I can't quite see how the geometry of adjusting a coilover would bring the wheel in that much, looks to me that I would have to dramatically shorten it?  So I suspect maybe something else is off.  But what?  Could the drive shaft be pushed in somehow?  Anyone one encountered anything like this before?    

Thanks!

camberer.png

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I'm not well-versed in the geometry of S1s (which used the driveshafts as upper control arms)

But I HAVE seen more than one Stevens Esprits that sagged lower on the driver's side. We removed the springs and dampers and swapped them side-to-side, which resolved that issue.

 

^^ Easier than losing weight, for the driver...

 

Atwell Haines

'88 Esprit

Succasunna, NJ USA

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46 minutes ago, LotuStuart said:

Off-topic, Jon, but is your website supposed to redirect to an asian dating site?

Whatever turns you on, I must get around to removing it from my profile as I gave up on it a few years ago now :hrhr:

Cheers,

John W

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1 hour ago, Bibs said:

I'm not saying those redirects are based on your search history but... 

:lol:

image.png

When domains expire, link farms buy them up and that's what happens...

 

hehe.

The link is now totally dead to me! Shows up an error.

This is my work PC, so is cleaner than the inside of a bottle of bleach. It must be because it redirects via this site.

#Eep!

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Hi Tristan,

Welcome to the community. First point to note is that the upper transverse link on any early Esprit such as yours is a fixed length U-jointed axle. What are known as CV axles normally are not fixed length, rather they accommodate arc movement with plunging mechanisms like ball bearings in tracks and so require the rear suspension have a separate upper transverse link of fixed length.

There are minimal measures available for rear alignment in the Esprit, involving shims at the inner end of the axle for camber, and at the chassis end of the large trailing arm arm for toe. So what you first need to do is examine the whole package for something which explains the variance between left and right spring perch heights. Also be careful to inspect both sides for looseness of the bearings both in the hub carrier and at the other end of the axle where it emerges from the transaxle. Probably best to have help shaking the wheel while you get a close look underneath and do have the tire up on a block in order to give you access for this and support the corner in loaded state. Keep us posted.

Cheers

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as Steve points out, the inboard end of the axle is supported and held in position by a double row ball race in the driveshaft housings. (unrelated to the bearings that support the crownwheel) This inboard driveshaft bearing should not allow any play whatsoever.  Assuming all bushes are in serviceable order,   I'd start taking some measurements off all your suspension pick up points to make sure there is no accident damage.  Also double check that things like driveshafts, dampers etc are absolutely identical on both sides.   You never know what bodges have been done before your ownership

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The dampers/springs only control ride height.  If all the other bearings & U/Js (as suggested above) are OK then too much negative camber is adjusted out by shims at the inboard end of the drive shaft:  Add shims to reduce negative camber and vice-versa.  It's like the Elite/Eclat.  It's a matter of adjusting the track and camber in stages as they affect each other, and may take several attempts to get it spot-on.

Pete

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Good points offered by the chaps above, to which I'd add the following. I have seen one instance in which an early Esprit displayed in-out movement (play) of the axle due NOT to a failed bearing but in fact due to the hub carrier being worn in the bearing register. Happily this was repaired by having the housing bored out a bit and sleeved for the bearing. Only turn over such work to a machinist who's competence is certain.

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Hello, Thank you all for taking the time to shed some light on this for me.  I am still leaning how all of this works and what things are called please so bear with me.  There are lots of different shafts and so on to keep track of so I edited the diagram so to see if I am understanding you all right.  The Rdent diagrams are helpful but don't show how it all fits together, and whenever I find a good photograph, I eventually notice it's not an S1, I am getting better though. Now I know the difference between CV axles and the s1 intermediate shaft, that helps a lot.

Seems like there are various bearing and so on to check, but if all is well, then I would add some shims in between the brake disk and the inboard end of the intermediate u-shaft, pushing the U-shaft out and adding camber so it's upright?  Shim is Yellow in this diagram.  

Thank you to the shim link, I am wondering how many of those I will need to correct my camber?

Should I be concerned that if this is indeed caused by crownwheel and pinion wear, and how would I know?

As far as I understand the way this is put together, the brake disk is sandwiched between the Shaft (not the u shaft) inboard, and the intermediate shaft on the other side?  I have attempted to show this in the diagram.  Is this correct?

I will go and check the measurements of the suspension from the pick up points (does that mean the pivot point of the various components?)  and see if it already has shims or not.

Thank you all again for your help with this. Prepare yourselves for more as, believe it or not, this isn't the only issue I am having with the car.

shimmed.png

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I haven't looked at the rear suspension diagrams for some time so can't recall exactly in which order the brake disc, adapter, shims, u-joint flange and diff output shaft all stack. Back into the garage shortly and will have a look at my assembly, post back here before long.

As to the crownwheel/pinion I see no way by which they can affect the wheel positioning ( alignment ) whatsoever. What is certainly known to be pertinent is the double roller bearing holding the axle assembly at the transaxle output housing. This would allow in-out float of the output shaft ( green in the lower right screenshot ) either by way of bearing failure or fretting the housing out of shape, in turn permitting in-out float of the entire assemble right through to the tire. The fixed length design of the axle assembly, that which permits its use as upper transverse link, cannot work if any of the entrained components are significantly out of spec. Any such deterioration will cause camber to drift off target.

Cheers

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The handy diagram drawn up and posted above does not show the driveshaft adapter, the piece which serves to attach the axle u-joint flange with the diff output flange. Attached here is a pic showing the adapter bolted to the U-J. 

The Service Parts Manual lists but a single shim for each side, and I'd not consider stacking more than that. No info provided on assembly order in either the Parts or Service Manuals. In the online parts manuals kindly provided by RD Enterprises the adapter can be seen listed in the brakes section, FYI.

Cheers

20231024_200245.jpg

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Thanks for picture Steve, so it looks like the shim attaches to the back of the adapter, meaning it sits behind the brake disk, not on the outside like I thought. I updated the diagram, does this look more accurate?

The car might have one already, I can’t see it, these are photographs of the rear brakes.

If I add shims here to correct the camber, won’t it will push the brake outward meaning the caliper will also have to be offset?

IMG_0714.jpeg.6802fa1564d92b842e1187a65215b55f.jpeg

IMG_6647.jpeg

IMG_6645.jpeg

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Thanks Rohan, I will give the u- shafts a good jostling and see if they move. I suspect that if that radius arm bushing is bad then they probably all are.   To fix the radius arms, would this polybush kit be the thing?

any recommendations on parts or bushing kits that are good and available would be welcome.

https://www.pnmparts.co.uk/esprit/esprit-s1-s2-s2.2/lotus-esprit-radius-arm-mount-6000

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1 hour ago, tristan reidford said:

any recommendations on parts or bushing kits that are good and available would be welcome.

Yes to your question on radius arm mounting & here's the lower link bush

I'd also give Steve a call when you order them & the shims & ask about the brake disk & calliper spacing, he's very knowledgeable.

Cheers,

John W

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That would be Steve at PNM with whom to speak. Rohan's points above are spot on, I'd overlooked the lower TCA bushes as possible cause. As my experience in Esprit rear suspension has so far been just  assisting one mate with diag of his failed hub register plus the teardown of my S2, I've limited perspective on how it all goes together. That said I'm confident you're correct that shimming inboard side of the adapter would move the rotor out of position, though the sliding caliper would likely accommodate.  

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Thanks again for the recommendations, I am building a speculative shopping list.  Since this car has been to an Esprit dealer here for an inspection, and been sent to an alignment place, I reckon they would have noticed bad bushing, especially if they were destroyed enough to cause such an extreme camber?  Maybe not.   Anyway I will check when I get some time so visit the car again.

So now I am thinking some collision damage has happened. I do have some reason to suspect this,  right before I bought the car, the dealer was taking it to a show in Miami, and when it came back it needed new mirrors.  Vague car dealer details were given, and I was reassured that it was not a big deal, and they have installed replacement mirrors etc. 

   I have yet to measure up the car, but I started thinking that if the lower control arm is the culprit, perhaps that is not centered.  From what I can tell it looks like the rear brakes are all one rigid unit built around the gearbox.  Since the rear suspension crossbeam is bolted directly to the caliper suspension brackets, which appear to be bolted directly onto the gearbox case with no adjustment, it seems unlikely.

Another question, is it possible that the Lower control arm is somehow incorrect?   For example say the LCAs of an S2 slightly is longer perhaps (!?), and one of these was mistakenly mounted to this car to replace a damaged LCA, and the camber issue ignored?  Sounds implausible that someone would do that.  I need to measure.

lotus_esprit_gearbox.jpg

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Differing TCA lengths unlikely, but do check in any case. Worth bearing in mind that the entire powertrain of S1/S2 Esprit is integral to rear suspension, as all joints connecting the wheels through to the engine are metallic. The engine mounts are subject to deterioration accordingly, so be sure to check them along the way.

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15 hours ago, drdoom said:

That would be Steve at PNM with whom to speak.

I actually meant Steve of SJSportscars but I'm sure the guys at PNM would be just as knowledgeable.

 

10 hours ago, tristan reidford said:

 For example say the LCAs of an S2 slightly is longer perhaps (!?),

They're both the same

Edited by jonwat

Cheers,

John W

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The elegant simplicity of the Esprit Rear suspension design makes this fairly straightforward, Tristan. I just reviewed your first pics which may indicate the left TCA is angled a bit from horizontal whereas the right seems about level. Would do to come at this right from where you first noted - the differing spring perch positions. I'd measure the loaded spring lengths for a clue, they're the same piece of kit so one would think they should be nearly the same length static. That said, I believe it is common for our Federal cars to have a spacer for the left side perch in compensation for drivers' weight in LHD configuration.  

It's Pete at PNM, is it not?

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