336 gearbox - Clutch will not disengage.

[GavinT]

Thanks for the pics, Dave,
I don't understand what you mean by this:

   You can see that the 821 has something that stops the gearbox from moving about 1/2” forward
    The 843 has the cutout with no stop in place .

What is the "something that stops the gearbox from moving about 1/2” forward"?


My understanding is that all 821, 843 & 807 cranks are essentially interchangeable (while ignoring the timing ends are sometimes different).
Similarly, the flywheels and blocks are interchangeable in terms of the dimensions we're interested in.
To me, that means any flywheel bolted to any crank will see the clutch cover bolt face at the same position. Happy to be corrected on any of this.

So, I also don't understand this:

** I MAY HAVE THAT BACKWARDS THE 843 JUTS OUT 1/4-3/8''. SO WHEN YOU PUT AN 821 FLYWHEEL ON AN 843 CRANK THERE IS A DIFFERENCE.

   That may be where the 1/2” story fall occurs.  Cranks are the same but that spacer/stop may allow the slop in the clutch pedal.

What is the "spacer/stop" you refer to?


My curiosity was peaked because this issue arises from time to time and is in contrast to my own experience. I merely purchased a clutch kit for an R16-TS and bolted it on with no issues.
It seems to me, somehow, some folk appear to be either getting different clutch parts or the stock engine parts are different and we haven't collectively figured it out.

Additionally, I've never seen the pronounced round faced release bearing you're using in any other 807/821 etc. related clutch.
The bearing seems short but I presume RD know what they're doing. Did you ever enquire with them?

[Pfreen]

I don't if this is relevant, but I looked in the Dave Bean catalog, which has a lot of Lotus tech drawings. 
Although they don't show the Renault engines explicitly, they state the round faced throwout bearing actuates a finger spring pressure plate where as the flat faced throwout bearing actuates a flat faced pressure plate spring.
You have not shown a photo of your pressure plate, at least I have not found it.
If your pressure plate looks like the one in the Lotus s2 parts book, the release baring should have a flat face.

[dakazman]

 Gavin,
 It seems the rear of the crankshafts are different. I will compare the flywheels and see how they are machined to sit on the crankshafts . That is probably the area of concern where the dimension of the pressure plate sits inside the housing and dimension to release bearing.
  Another dimension I would like to know is after the bearing touches the pressure plate to complete disengagement.  Which is probably equally important.

 I only have one Renault bellhousing so I cannot compare from that side which cannot be changed anyway because the length of the gearbox doesn’t change.

The KIT works fine in an unaltered drivetrain. After we figure this out and only then I can make a statement  on original cars .  My information was or is the same as yours, at the time, that the cranks are the same.

 I have a TC housing but I’m not bringing in something else , but it was attached to a 336 gearbox.

 
   Pfreen,
  Posted the pic of the pressure plate and will check drawing. 

[Pfreen]

That looks correct as far as the throwout bearing and pressure plate.  It does not look like the Lotus parts manual though.

[Bryan Boyle]

That looks correct as far as the throwout bearing and pressure plate.  It does not look like the Lotus parts manual though.

The OEM pressure plate and original flat face throwout are NLA, and have been for a while (I do have an unused  set, but it's been promised to someone...)

[dakazman]

  Thanks Bryan, I have a good bearing.

 Paul,
  This pic shows the parts in the manual.
 
 Gavin , you’re correct the crankshafts are the same( the pilot bearing was out which made it look different than the 821 with bearing in . the flywheels are in question . I checked my flywheels both were for the 821 wedge engines  the cross flow (843) crank and flywheel are in the car.
Now.  I remember comparing it years ago but can’t find the thread just yet.
  So anyone out there with a crossflow engine with a 336 have the new clutch kit?

[GavinT]

Dave, a coupla things.

1. That pic of your new pressure plate - are the fingers slightly curved towards the middle and not straight? I'm wondering if that has something to do with the bold round faced release bearing.

2. I wonder what RD might comment as to the issues you've encountered.

3. In the name of science, I dragged out my 336 gearbox for a photo shoot.
This gearbox was attached to an 807 from a R-16TS. Long ago I sold the engine to a needy Europa punter so I don't have a pic of the clutch. The clutch was new when I rebuilt the engine and was of the later type with bare fingers and not the older type with the circular 'pad' on the diaphragm spring (at least, that's how I remember it).

I measured the distance from the face of the release bearing to the forward face of the bell housing where it bolts to the engine.

70.25 mm = 2.77 inches = 2 3/4 inches

Does this narrow anything down?

[dakazman]

 Hi again Gavin,

 Thanks for answering so soon.
  I don’t have an extra s2 housing to check or another 807 flywheel. I’ll pull the gearbox out after I road test it .
 
 I’m going to put finding an answer for awhile, I just want to finish the A/C lines then charge up. Test and close up the firewall. Bleed brakes and install the interior. Than the windscreen .
Dakazman