Lotus Elan and Lotus Elan Plus 2 Forums

Hi,

PLEASE CAN SOMEONE HELP!!!!
I am currently restoring a s3 elan I have re-built the engine and replaced the clutch. The gearbox has been checked and is ok.

The engine and clutch was completed a few months ago, fitted to the rolling chassis and has been left standing.

The body is still seperate to the chassis and engine.

I have attempted to start the engine only to find that the engine was solid and would not turn over even when the spark plugs have been removed to eliminate the compression.
The gear box is in neutral.
The starter motor is new but has also been checked to confirm it is not the issue.
When the clutch is activated (ie as if the pedal is depressed) the engine can be turned over without issue.

Can anyone please explain what is wrong? surley with the gearbox in neutral the clutch should not prevent the engine from turing over.

thanks!!!
Gazzamuffin

gazzamuffin wrote:Hi,

The gearbox has been checked and is ok.
I have attempted to start the engine only to find that the engine was solid
The gear box is in neutral.
The starter motor is new but has also been checked to confirm it is not the issue.
When the clutch is activated (ie as if the pedal is depressed) the engine can be turned over without issue.
Can anyone please explain what is wrong? surley with the gearbox in neutral the clutch should not prevent the engine from turing over.

Hi Gazza & welcome,
The engine should turn over if the g/box is in neutral and it should also turn over if the car is in gear providing the the hand brake is off and the rear wheels are not on the floor.
It would appear that something in the g/box is peventing it turning, are you sure the gearbox is ok? if there is a problem inside the gearbox it is possible that it could be in two gears at the same time which would prevent rotation.
Another thing that comes to mind (although unlikely) is that as you depress the clutch the crank is moving slightly forward and clearing something that is jamming?

Gazza, how are you disengaging the clutch with the body off?? Just curious because obviously you are, based on your diagnosis; just curious.

I agree with Brian, most likely the gearbox has two gears engaged. Does the stick 'find' all four gears and reverse?

Greg Z

Gazza,
I can confirm that it is possible to partly engage first and reverse gears at the same time, I have managed to do it somehow in the past, this can easily corrected however by removing the cap and gear lever and putting the selector rods back in the neutral position using a large flat blade screw driver then refitting the gear lever, nylon cup and cap.

Thanks To all for you replies!

I shall take a look and keep you all posted !

Thanks again!

Hi all,

I have an update, but not a positive one.

I have checked the gearbox and can engage each gear including reverse. however it is still impossible to turn the engine over when the clutch is engaged (foot of the pedal).

Just to confirm I am able to engage and dis-engage the clutch using studing and nuts inplace of the clutch slave cylinder.

I checked the gearbox by removing the top plate and rotation the propshaft (which is disconnected from the diff) to watch the gears as they rotate, then moving the gearlever to engage each gear.

So, I can only assume that the problem lies with the clutch, could i have fitted something incorrectly which would prevent the shaft from rotationg in nutral when the clutch is engaged?

again any suggestions would be most appreciated!

Thanks

Gazza

Have you checked that the clutch plate is installed the correct way round. Flywheel side actually facing the flywheel.

Mick G

Hi MickG,

That is one thing that I can not confirm if it is correcly fitted or not... I think my only option is to now remove the engine and box from the chassis to strip it and confirm that.


Thanks

I was going to ask the same question as MickG.

Also when the clutch is engaged are you able to turn the gearbox over from the propshaft (gearbox in neautral)

And with the clutch engaged and no slave (or studding in place) is the clutch fork floppy and free to move?

Simon

Your check of the gearbox does not seem conclusive.

Check if the gearbox is jammed, by jacking up the rear of the car, prevent one rear wheel from turning and then by hand turn the other rear wheel, with the clutch disengaged.

You should be able to rotate the rear wheel. Check each gear setting, it will be harder to turn the wheel in some gear settings. If it only rotates in neutral, then as you deduce it is a problem between the clutch & input shaft of the gearbox.

I suppose what might have happened is that the splines of the gear-box input shaft did not engage properly in the splines in the clutch and the shaft is in fact pressing the clutch into a jammed condition.

The cluch being jammed would result in permanent drive since it is self contained.

You have rulled out the starter motor.

Check that the clutch fork is free to move when the clutch is engaged - it is the only thing that is moves and therefore able to jam things up.

Then remains the axial force applied by the clutch fork -

On the engine side as types 26/36 mentions something could be locking/unlocking the crank - Measure the gap between the front cover and pulley with the clutch engaged/disengaged to check for movement.

On the gearbox side you say that the problem occurs even in neutral so that rules out operation of the gearbox components - the input shaft is separate from the mainshaft - Measure the gap between fourth gear and the gearbox case with the clutch engaged/disengaged to check for movement.


The above should help identify what is jamming with what.... which will hopefully lead you to identify why.

Good luck!

Simon

...when you turn the engine over... do the wheels turn - as if it's in gear?

I've had the clutch in the wrong way round (managed to blame it on being distracted by a four year old ) - the effect was the same as having no adjustment on the clutch ie: only massive amount of clutch arm movement moved the plate away from the flywheel - still dragged though.

Also had the spigot bearing break up when pulling away from the lights. Effect was same as being stuck in gear with no clutch at all (could still change gear with engine off and stationary - it was a while ago so memory dims) Transporter home

Good point from Simon - check release bearing didn't 'fall over' when you assembled everything.

not sure if any of the above helps.. just my 10cents

...actually, shouldn't take you long to seperate g/box engine with it sitting in the chassis and no body on

Hi all, as promised im back with an update.

The enginer and box is back out of the chassis !

I have detached the gearbox from the bellhousing and can confirm that the input shaft is stuck solid as if it is jammed.

There is enough play to pull the shaft forward enough to just about get hold of the bearing and roatate it, so the bearing does not seem to be the issue.

From the rear of the box - I can rotate the main shaft (output shaft) when in neutral and can engage all 4 gears and reverse.

So the problem seems to be at the input end.

I am planning to strip the box down this weekend to investigatge further so if anyone has any tips please let me know!!

(this being my first time ive ever worked on a gearbox im nervous to say the least!!)

while it is being stripped, can anyone recommend what I should replace as a matter of preventative maintenance?

thanks !!

Gazza

The input shaft sits in the front of the gearbox on its bearing and the mainshaft is supported in the centre of the input shaft.
The input shaft teeth mesh with the front gear teeth on the laygear, these are in constant mesh so if you say the input front bearing appears ok then I suspect that the laygear is not rotating for some reason.
There is obviously a slight amount of play between the constant mesh gears, if you hold the input shaft and rotate it forward and backward can you detect a very slight amount of play? if so then I think it would confirm that the problem is connected to the laygear and the input shaft is not the problem.
I think the disassembly procedure is covered in the manual so just follow it taking note where everything is even take pictures for reference.
Good luck.

In your first post, you indicated "the gearbox has been checked and is ok". Don't go back to this person for the rebuild

Pull the top cover carefully, as there are three detent springs that could drop in the box, and peer down to see if perhaps, earlier, something was dropped in and has now jammed the layshaft to keep it from rotating.

Greg Z