Clutch alignment tool

[Paul Coleman]

Okay, here I go showing my ignorance again...

 

Do I need to buy a clutch alignment tool to refit the clutch on my S1? I am a mechanical retard so I don't actually understand what the problem is. Can't I just take input shaft out of gearbox, fit shaft through clutch and into crank, fit gearbox to shaft? Job done!

 

Thanks, Paul.

[andy b]

Paul yes you can if you have the engine and box out of the car. leave the clutch cover loose But tight enough to hold the clutch plate in place use your eye to align the spline in the clutch plate jiggle the g/box to fit to rear bearing in the crank bolt gear box to engine then tighten the clutch cover through the timing hole in the g/box one bolt at a time should work remove g/box check and tighten the clutch cover.

then refit g/box by hand it should fit nice without pulling it up on the bell housing bolts. 

Your problem is when the clutch plate is not in line with the end of the crank. the nose of the gear box will not engage in the bearing in the crank. But please replace the bearing in the end of the crank they do a lot of work.

[910Esprit]

Paul  -  An input shaft makes the perfect clutch alignment tool - However, you should not be able to remove the input shaft from box  without removing the notoriously tricky snap ring.   These can rust out.  Has yours gone? 

[softlips]

I've never done a clutch on an Esprit but every other car I've done them on I've aligned them without the alignment tool I bought years ago for the job.

[Paul Coleman]

Paul  -  An input shaft makes the perfect clutch alignment tool - However, you should not be able to remove the input shaft from box  without removing the notoriously tricky snap ring.   These can rust out.  Has yours gone? 

Uh-oh!!

 

Need to double check but I think I can withdraw it completely from the gearbox.

[910Esprit]

_{OK - Not the end of the world and on the plus side you can use it to align the clutch!}

 

_{The input shaft is spring loaded to pre-load the imput shaft against the Nylatron washer.}

 

_{The function of the snap ring is to stop the spring from ejectling the input shaft.   All you need to do is check you still have the spring, clean out the snap riing groove and refit a new one.}      

[molemot]

I find I can extemporise an alignment tool from bits of socket set and sockets...and maybe a bit of insulating tape to wind around it to get the fits right.

[Paul Coleman]

_{OK - Not the end of the world and on the plus side you can use it to align the clutch!}

 

_{The input shaft is spring loaded to pre-load the imput shaft against the Nylatron washer.}

 

_{The function of the snap ring is to stop the spring from ejectling the input shaft.   All you need to do is check you still have the spring, clean out the snap riing groove and refit a new one.}      

Okay, I can definitely remove the input shaft completely from the gearbox and I can't see anywhere that I could fit a circlip to...

 

I spoke to Steve at SJ and he told me that there's a common problem whereby the spigot bearing moves up the crankshaft and causes this. My spigot bearing has indeed worked its way into the crank by about 3 or 4mm (can't measure it properly as it's currently on the engine stand). According to Steve I need to take the bell housing off and disassemble part of the gearbox. However, he reckons that once I open up the diff I will then find that the crown wheel and pinion will probably be knackered. At that point he didn't elaborate as to what the solution was... but it sounds expensive ;o)

 

Has anybody done this little job and can give me a few pointers as to what I'm letting myself in for as I'm not sure I want to play any more.

 

Yours, depressed of Bedford.

[910Esprit]

The snap ring is located in the sleeve that the input shaft is inserted into - not the shaft itself.

 

Steve is being ridiculously pessimistic.  There is more chance that the CW and Pinion will be in perfectly serviceable condition.  However, he is correct to say that the Bellhousing needs removing to rrefit the snap ring.   On the plus side its a good opportunity to replace the (cheap) crown wheel support bearings.  Although no real specialist tools are required, its a reasonably involved process to accurately reset the preload and backlash.    

[Paul Coleman]

I've got the manuals out but I haven't yet figured out what I need to do to get at this pesky circlip. He seemed to suggest that I need to take the output shaft housings off as well as the bell housing although to be honest he lost me at some point as I'm a bit of an automotive mechanical retard!!

 

Cheers, Paul.

Edited July 21, 2014 by Paul Coleman

[molemot]

You need to remove the bellhousing.

The very first thing is to drain the oil and then get everything squeaky clean. Not a spot of dirt, road grit, or anything else.. Removing the bellhousing involves undoing the drive shafts, as they bolt to the gearbox casing and the bellhousing. If you are very careful, you can undo and remove the fasteners which go through tthe driveshaft flanges and into the bellhousing, and undo and loosen those which go to the gearbox casing, then drop back the drive shafts to enable the bellhousing to be lifted off.

 

This is all best done with the gearbox held firmly with the bellhousing opening upwards and the end of the gearbox downwards. Undo the fasteners going through the inside of the bell housing into the gearbox....you have remembered to clean the inside of the bellhousing, haven't you?(!) The thing is, if you manage to avoid contamination then things will be simpler....a spot of dirt or grit into the innards and it's a total strip down and reassembly ensuring cleanliness.

 

The drive shafts have gaskets between the flanges and the gearbox, so be careful when pulling off the bellhousing...preserve these gaskets. Anyway, assuming you have lifted off the bellhousing, there is a tube through which the clutch shaft runs....pull this off...and then the dreaded circlip is down inside the end of the gearbox first motion shaft.

 

It's a fiddly job, but using fine nosed pliers and thin screwdrivers you should be able to get the circlip...or the remains of it...out of the shaft. Clean out the inside of the shaft, removing the spring inside and ensuring everything is clean and you haven't dropped any bits into the gearbox....!!! Inspect the crownwheel and pinion (which is part of the gearbox mainshaft) , being careful not to dislodge the bearings.

 

If all is well, the spring goes back into the end of the shaft, the circlip slides over the clutch shaft splines, the clutch shaft pushes in on the spring and you use some half round tubular thingy (I used a split and opened out length of copper tube)  to push the circlip down the inside of the first motion shaft until it clicks into the recess down inside the hole!! Once it's in properly, the shaft should push in against the spring but not come right out.

 

Now you put it all back together again.....very carefully to avoid damaging the gaskets or the O rings on the tube. Use a new Nylatron washer and it's a good idea to use a new roller bearing in the back of the crankshaft...this should be pushed in until the outer face is flush with the end face of the crankshaft....not flush with the inside of the chamfer. Getting the crank roller bearing out is best done by stuffing it with thich grease until you can get no more in, and finding some rod that just fits into the bearing...then WHACK it with a hammer! A good positive thump transmits the force through the grease and pushes the bearing out....i have heard of people using bread for this(!)

 

It's fiddly to do, and you have to be well disciplined...making cardboard holders for the stub axle fasteners, for example, with holes through them corresponding to the holes in the flanges, so you know where the individual fasteners fit...but if you keep thinking, read everything you can find on the subject on these pages and elsewhere, keep thinking, be systematic and KEEP THINKING you should be OK.

 

This was all from memory, but there is a fuller acount of my gearbox fun and games elswhere...and I think our resident Italian precision engineer, Giorgio, has an account of his own, too....his has photos; I found photography interrupted what I was doing, so I just got on with it and wrote it up after!

 

Have fun......

[910Esprit]

John - Do you think there is any real prospect of not damaging the driveshaft housing gaskets when removing?  I've rebuilt 4 (possibly 5...)  of these boxes and that's a feat I've not achieved.  Paul the significance being that the gaskets are part of the pre-load calculations.

[Paul Coleman]

Thanks for the reply John - I had just started a new thread with a more descriptive title as I didn't think anybody would answer this one!

 

That sounds like an absolutely horrible job

 

Am I right in saying that this pesky circlip is no. 24 in this picture... http://rdent.com/manuals/esprit/transmission/fe.htm ?

 

I also believe that when you remove the output shaft housings there are some shims in there somewhere that have to be put back exactly as they came out?

 

Could you nip over and give me a hand? Hahahaha

 

Thanks, Paul.

Paul the significance being that the gaskets are part of the pre-load calculations.

Oh good that's even better!! I've gone right off this bloody car!

Edited July 21, 2014 by Paul Coleman

[Paul Coleman]

Another thought - what are the consequences of not replacing the circlip? If I fit a new spigot bearing in the end of the crank so that it is flush by adding a spacer behind it to stop it moving then won't that cure the problem and mean the circlip is not needed?

[910Esprit]

You are correct.  Once installed the snapring (its not a circlip ;-)  serves no function at all.  It is purely there so to keep the shaft from ejecting due to the spring trying to push it out.   If you can keep all in place whilst assembling  - job done!

[giorgio67]

You must install the circlip Paul and the SJ spacer is useless....

best thing you can do is to order a new circlip from Harry Martens, DS Vitesse, it's a new design circlip built with different material and it's the best upgrade for the inputshaft/gearbox, it will never fail, the original does....

Also, the problem is more evident in the later esprit and turbo cars, as Tim Engel said, the new design of the input shaft is not good to retain the circlip due to a splines design change, so if you need to buy a new inputshaft don't buy the original Lotus  (later type) but buy again from Harry, his new shaft is machined to solve the problem..

Giorgio

[910Esprit]

Giorgio - As above the snapring has no function once installed!  Also, the original fails through rust, there is nothing at all bearing upon it in service  (as the input shaft bears upon the Nylatron washer)

 

(However, I agree the aftermarket spigot bearing spacer is useless and counter productive....)

Edited July 21, 2014 by 910Esprit

[Paul Coleman]

You must install the circlip Paul and the SJ spacer is useless....

best thing you can do is to order a new circlip from Harry Martens, DS Vitesse, it's a new design circlip built with different material and it's the best upgrade for the inputshaft/gearbox, it will never fail, the original does....

Also, the problem is more evident in the later esprit and turbo cars, as Tim Engel said, the new design of the input shaft is not good to retain the circlip due to a splines design change, so if you need to buy a new inputshaft don't buy the original Lotus  (later type) but buy again from Harry, his new shaft is machined to solve the problem..

Giorgio

To be honest Giorgio I don't really even see what the problem is that causes this!! Is the shaft not long enough or something?

 

Surely the spacer is useful in that it stops the spigot brearing from being pushed into the crankshaft - although why it gets pushed in there I don't know.

[giorgio67]

No function Steve?

There is a spring pushing the shaft mate....it fail because it's poorly designed and the spring pressure is the problem to solve for the snapring.

Had tons of chat with Harry and Tim about that during my gearbox rebuild, using original circlip and new style of shaft is asking for trouble....

Giorgio

Sorry Paul, I can't agree with you,

the spacer is totally useless, bought one and not installed....the problem as I said is the spring pushing the shaft.

If you want to do a definitive job, have the cranshaft machined and the end of the inputshaft too, to install a normal ball bearing from SKF like the renault set-up, it's a easy and not expensive job to do and it will solve the problem for ever, as the Harry circlip do...

 

Giorgio

[910Esprit]

No no no Giorgio - Think about it - do you believe the spring is forcing the input shaft against the snapring or the nylatron washer?  It cant be both.   Also look at the photo above, there is absolutely no machined precision lip for the snapring - it just bears against the chamfer - the idea that would accurately locate the shaft in service is not credible....     

[giorgio67]

Steve,

please see the attached pic.

As you can see this new shaft design is totally different from the original one....no chamfer (the problem...)

it's designed to retain the ring with a LIP, sorry Steve I would not be offensive and excuse my english but if a men working for a life on these gearbox has designed and produced this upgrade I think there is a reason... or not?

 

Ciaoo

Giorgio

[910Esprit]

Final post from me as its now counter productive.   However, nothing whatsoever touches the snapring once the gearbox is installed....    After installation, what mechanical purpose do you think it serves Giorgio?  Who on earth would develop such an application without a thrust washer if that was being 'beared' upon by that splined shaft in service.  Look at any Nylatron washer - it always has the witness marks of the load of the input shaft.

[giorgio67]

Steve,

that's my first controversy here in 7 years as it's not on my taste.

What can I say more?

You are right, and Harry Martens Tim engel and me are 3 idiots....

 

Giorgio

[Andyww]

To be honest Giorgio I don't really even see what the problem is that causes this!! Is the shaft not long enough or something?

 

Surely the spacer is useful in that it stops the spigot brearing from being pushed into the crankshaft - although why it gets pushed in there I don't know.

 

The reason it gets pushed in is there is longitudinal pressure on the input shaft when the clutch is engaged. Force occurs when the clutch disc is driving the input shaft at the clutch bite point because the spines dont slide easily owing to the torque being transmitted and the driven plate is being pushed against the engine therefore the input shaft is also being pushed. This slight pressure/movement can add up and cause the bearing to move each time very slightly if its not very tight. Adding a spacer here to prevent this makes perfect sense.

 

There might be a view that the circlip is there to maintain a gap between the input shaft shoulder and the bearing to prevent this movement from pushing on the bearing but I would be very surprised if this is the case. I would say the circlip is simply an assembly aid to prevent the input shaft falling out of the gearbox. The reason the shaft is sprung would be to remove tolerance criticality on the whole engine/bellhousing/gearbox interface, and adding a circlip to maintain a defined gap would reintroduce a potential tolerance problem thus defeating the purpose of the spring.

 

Also the terminolology used, the nylon washer is described as a thrust washer therefore its intended to take the thrust. If there was a gap maintained it would not be a thrust washer, in fact there would be no purpose in fitting it.

 

I would say if the circlip has gone just ignore it. Fitting the spacer would be good.

[Paul Coleman]

I spoke to one of the mechanical engineering lecturers here at work today (I work in a college) concerning this problem. He has a background in the automotive industry and did his first degree in Mechanical Engineering followed by a PhD in something to do with engine design (don't ask me what!).

 

His opinion is that the snap ring is purely for assembly purposes only and plays no role other than that. He said that the snap ring breaking could be the result of rust or possibly a manufacturing problem with the quality of material they used. He mentioned that relying on a snap ring to take any kind of loading would be a very bad design.

 

He couldn't see that the loading on the crank spigot bearing was going to be that high as the type of spigot bearing is not designed to take axial loading. He also said that if there was a large force on the input shaft it wouldn't have made sense to have used a nylon washer on the end of it. He speculated that the bearing being pushed into the crank could have been the result of misalignment when the input shaft was pushed through the clutch and into the end of the crank.

 

For my personal situation his suggested cure was to add a spacer behind the spigot bearing, leave out the snap ring (as it's a lot of work to replace it) and use the input shaft as my clutch alignment method.

 

I did mention my reservations about fitting a spacer in the end of the crank in case I want to get the new spigot bearing out in the future and he suggested machining one from aluminium and tapping a coarse thread down the middle of it so that I could use a bolt to make up a puller. He also suggested machining away some of the material on the outside so that it looked like a cotton reel to keep the contact surfaces down, making it easier to get out if I ever needed to and fitting it with copper grease.

 

He looked at the picture of the replacement input shaft as shown above in Giorgio's post and he commented that due to the stresses on the shaft it is better to have a radius from the shaft to the splines (as per the original) rather than a right angle as seems to be the case in the replacement (if you look at the right hand side). He said that you don't want sharp edges as it causes a weakness at that point. The exception is when the splines are rolled onto the shaft as they do for things like rally cars (I think that's what he said).

 

I'm not very mechanically minded I'm afraid so I can't really comment on the above in any kind of technical depth but what he said seemed to make sense.

 

Interested to hear other people's opinions. I've got a PhD Physicist on the other side of me at work, shall I set him on it next hahaha

 

Paul.

Edited July 22, 2014 by Paul Coleman