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My 87 Turbo Esprit in the shop for several issues (bushings, engine mounts, new shocks). However, the clutch also started to act up - it felt like slipping at speed, but around town it was working somewhat OK. The clutch take up was getting longer and longer - to the point where I was able to release the clutch SLOWLY in 1st gear and zero RPM drop and car didn't move forward. No grinding or any noise.

But, if I let the clutch quickly, it engages and seems to work. This is peculiar as the clutch hydraulics were also replaced; there was a slightly leak in the slave cylinder, but otherwise nothing really 'wrong'.

I have a full clutch kit on standby if it is needed. The car repair was stalled by the need for a shock spring plate (custom machined). So once they get the car drivable, they will check the clutch and replace if necessary.

My theory - something failed on the clutch assembly (the disk springs weakened?) - it acts somewhat like my old Nissan Sentra - when the clutch failed, it failed HARD - car would not move. This was unlike my VW where at least the car can still be driven for a long while, albeit slipping.

Never saw this behavior on my late 88 and I put 50K miles on that one.
 

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Hydraulics would of been my first guess but now I cant see how the symptoms you describe would be that.

I had a car one time where the fork that the slave pushed on to move the TO bearing fatigued and cracked and that produced some very odd behavior.

Now I am leaning toward the "fingers" on the PP, I guess they are springs.

Very curious to see what the diagnosis is.

How many miles on the clutch disc and PP?
 

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Could be hydraulics but if you have a lot of miles on the clutch I suspect the culprit is a worn friction disc or wear on the "fingers" of the pressure plate where the TO bearing contacts it, or some of both. Make sure to have it checked because the friction plate if worn down to the rivets can mar the flywheel rendering it unusable.
 

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My first guess would be a problem with the clutch master cylinder. If that doesn't fix it then the clutch has to come out to figure out the problem.
David Teitelbaum
 

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My first guess would be a problem with the clutch master cylinder. If that doesn't fix it then the clutch has to come out to figure out the problem.
David Teitelbaum
This is my guess as well. What color is the clutch fluid at the master?
 

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I would also first confirm the hydraulics as that the easiest starting point but i have seen this once before, The P.O had had a new clutch installed and the flywheel 'resurfaced', but incorrectly (no step) The clutch lasted quite a while but eventually, due to normal wear, no longer had the clamping force to adequately ensure solid contact.
 

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Discussion Starter #7
The clutch had documented 10K miles since 2015. The PO told me parts were from JAE ordered by the shop he had do the work. My suspicion is also on the pressure plate fingers being defective given the low miles.

The clutch kit from JAE, if needed ( and likely from what I’m hearing) also includes a new flywheel since I also had reports of starter grinding issues.


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RE: hydraulics - yes the fluid looked kinda dirty (both Master/Slave were replaced with new/rebuilt units from JAE). The mechanic says the slave had some minor drip but not clear if bad enough to cause the clutch issue. And since it isn't grinding at all, I'm really suspecting the clutch disc/pressure plate 'finger' failure.

I'm curious about this statement: "The P.O had had a new clutch installed and the flywheel 'resurfaced', but incorrectly (no step) " - the Lotus manual mentions something about not resurfacing the flywheel (but no explanation why). That's why I bought a new fly wheel too along with the clutch disc, pressure plate, throw out bearing, etc. The car already has the stainless steel hydraulic clutch line so that helps.
 

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Update: picked up the car last week after ~ 6 weeks in shop ( waiting for custom part for front shocks and other personal reasons). The master and slave clutch cylinders ( From JAE) were replaced and magically the car is working fine now. The mechanic saw none of the slippage I reported and the take up point where the clutch engages is much earlier than before. In fact it is the same now as another 4 cyl Esprit that remember driving. The slave had some signs of dripping but I never saw a puddle on the ground where parked. The symptoms didn’t seem consistent with leaking hydraulics ( no grinding) so I’m at a loss for the actual reason.

I also had front and rear old polyurethane bushings replaced with SJS ( and a few JAE) rubber bushings as well as Gazmatic shocks. The rear left driver shock was completely leaked out and the rear left driver upper link polyurethane bushing was damaged from exhaust manifold heat. Car handling/ride amazing now! The shocks are adjustable and seem a tad stiffer than I recall. Will tweak it ( knobs are at bottom of shock) and see what works best for me.

Here’s the damaged polyurethane bushing next to I damaged ones - you can imagine the squirrelly handling I was getting from the rear of car.




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RE: hydraulics - yes the fluid looked kinda dirty (both Master/Slave were replaced with new/rebuilt units from JAE). The mechanic says the slave had some minor drip but not clear if bad enough to cause the clutch issue. And since it isn't grinding at all, I'm really suspecting the clutch disc/pressure plate 'finger' failure.

I'm curious about this statement: "The P.O had had a new clutch installed and the flywheel 'resurfaced', but incorrectly (no step) " - the Lotus manual mentions something about not resurfacing the flywheel (but no explanation why). That's why I bought a new fly wheel too along with the clutch disc, pressure plate, throw out bearing, etc. The car already has the stainless steel hydraulic clutch line so that helps.
Eddie,
They can and are frequently machined, but note that this is only if there is not significant wear of the flywheel beyond the factory specs, which is a measly 0.5mm but i have seen a lot more removed with no ill effects (obviously not supported by the factory so owners discretion) also they should not be 'machined' in the typical sense (lathe) but need to be Blanchard ground and the step must be maintained per factory instructions. From the factory:

The recommended minimum thickness of the flywheel is 23.50 mm, which means
that only around 0.5 mm should be removed. The friction face of the
flywheel must be 0.5 to 0.6 mm proud of the surrounding cover mating face to
provide the correct clamp load. If your flywheel shows no evidence of such
a step, it is likely that the flywheel has been incorrectly machined
previously, which would exacerbate any clutch slip problem. You may choose
to use your own judgement, or that of a qualified engineer and machine the
flywheel to a lesser thickness than this, but on that I could not comment.
Yours sincerely,
Dave Massey - Technical Service
Senior Technical Author
Lotus Cars Ltd., Hethel, Norwich, Norfolk. NR14 8EZ

This link has several posts on maintaining the step and the effects on the clutch if its not done:
 

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Hi Colin - thanks for the explanation - given I pay mechanics to do these jobs, figured it was less expensive in the long run to just put in a new fly wheel if the transmission had to come out now.
Also, the mechanic mentioned a weird grinding during start - as if the flywheel teeth were gnashing with the starter.

I've never hear that before, but again if coming out with the clutch, may as well have a new flywheel on standby if the teeth were getting ragged.

Since I don't daily drive (more specially - not daily drive 12K miles/year - more like 2500 miles every lunch time :) ) it may be awhile before the clutch comes out.

I am approaching (arrived?) at the mileage (78K) for replacing the differential bearings - I may just do it all up next year while I'm on vacation.
 

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Discussion Starter #12
Another interesting followup - check out this time line:

2011 - Mike B (2 POs back) 's2mikey' reports he replaced master/slave clutch cylinders due to weird behavior - he too thought clutch was going out.
2015 - Mike L (1 PO back) 'delomike' - SMSed him yesterday and he said in 2015 he replaced master/slave clutch cylinders as well
2020 - I have both replaced due to erratic clutch behavior - different than 2011 Mike L experience, but still appears to be non-durable master/slave clutch cylinders.

My late 88 Esprit - the shop in 2011 put in a rebuild unit leaked after 1 year - put in another (new from JAE) and it lasted 40K miles/40 months until the totalled collision in 2015.

So for me, the master/slave cylinders don't seem to have much of a life; and spotty ones at that.

These were from reputable Lotus vendors - the late 88 Esprit accidentally has a rebuilt unit (unknown source) (I specified new) so that was suspect.
 

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A bad clutch master can cause all kinds of weird problems. I had one where when you pressed the clutch pedal down it was fine but after less than a minute it was as if you didn't step on the clutch at all. There is a valve inside the master cylinder that locks the pressure in the slave cylinder when you step on the pedal, when it leaks you engage the clutch even with the pedal to the floor. Can't pump the pedal like you can the brakes to "get a pedal" back. What you really should do to extend the longevity of the clutch hydraulics (and the brakes) is to flush and bleed the systems annually. Contaminated fluid damages the internals of the systems and results in problems. Much cheaper to change the fluid.
David Teitelbaum
 
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