[Healeys] FW: New clutch query

[Bob Spidell]

A bit off-topic, but while the bell housing is on the bench it might be 
a good idea to install thread inserts in the threaded holes that fix the 
slave cylinder bolts. These tend to get bunged-up with repeated R&R of 
the slave cylinder, and it's steel bolts into aluminium holes. I don't 
think I'd be comfortable with cutting the upper bolt's head off either; 
the slave cylinder is secured by tension and if any threads are exposed 
this could cause fretting on the slave cylinder hole (probably not an 
issue the way our cars are driven now, but over a hundred thousands of 
miles or so).

Not mentioned so far is the lever that operates the release bearing; the 
shaft on which said lever pivots gets worn over time, allowing some side 
play. My BJ8's lever had noticeable side play at over 200K miles; my dad 
didn't think it was a big deal, but I figured it would keep me up at 
nights if I didn't replace it. It ended up being a bigger job than it 
should have been, given the parts available from the 'usual suspect.'

Shipwright's Disease in action.


On 9/19/2021 10:07 PM, m.g.sharp--- via Healeys wrote:
>
> Simon, hate to say it, but the clutch should work perfectly after it 
> is installed, there is no “break-in”.  The trouble you had getting the 
> g’box in is troubling.  If everything is aligned it  should slip in 
> easily.  I presume, when installing, you put it in gear and rotated 
> the drive flange to get the shaft splines to align with the clutch 
> plate.   I would never pull it together by winding it on with bolts. 
>  Your description that the graunchy noises when shifting are expensive 
> sounding is likely correct, so it sounds to me that the gearbox should 
> come out again and a thorough inspection is warranted.
>
> In addition to checking that the clutch disc slides on the first 
> motion shaft splines _before _assembly, I also always check that the 
> pilot bush fits correctly on the end of the shaft.  If these fit 
> correctly and the alignment is good, the g’box should slip in easily.  
> Now, you may have to destroy the bush to get it out of the flywheel, 
> but they are inexpensive and the peace of mind (never mind the effort 
> to re&re the g’box again) makes it worthwhile to do. The pilot bearing 
> should be lightly greased before assembly – I use a molybdenum grease, 
> which I also use sparingly on the splines – don’t put so much on that 
> it flies off and contaminates the clutch plate).  I agree with Richard 
> that a spare first motion shaft is a better alignment tool than a 
> plastic substitute.
>
> Also, ensure that the bell housing to engine bolts are correctly 
> located.  There are two special bolts called “dowel bolts” (they have 
> their own part number that is different to the other bolts) that are 
> more precisely machined to locate the bell housing/gearbox accurately 
> on the rear engine plate. They can be identified by a shallow groove 
> that is machined into the shank just below the head.  They go in the 
> top left (11 o’clock) and bottom right (5:25) holes (looking at the 
> rear on the motor).  See the note on page 97 of the Originality Guide 
> (2018) for a full description.  I don’t think the workshop manual 
> adequately describes these, thinking it is covered under “replacement 
> is the reverse of removal”; but you have to be pretty observant to 
> note these two bolts on removal!
>
> Three years ago I had an issue with a new Borg&Beck clutch plate and 
> had my g’box in and out 3 times, so I know how you are feeling, but 
> something is wrong and you need to get it right.  When it is together 
> again, bolt the driver’s seat back in and test drive it before putting 
> the rest of the interior in; it saves a bit of work if there is a problem.
>
> Lastly, don’t cut the head of the top slave cylinder bolt.  I can 
> guarantee you that if this was acceptable engineering practice the 
> accountants at the factory would have insisted it be done.  The slave 
> cylinder needs to be securely fastened to the bell housing and one 
> bolt is not sufficient.  I have probably had mine off 4, maybe 5 times 
> in 45 years of ownership, so if it takes me an extra 10 minutes to 
> remove, so what?  If extracting inaccessible bolts is a big issue, 
> don’t buy an English car!  (I just had to re&re the rear drain pipe 
> from the intake manifold – that is another fun one!).
>
> Good luck! Mirek
>
> *From:*Healeys <healeys-bounces at autox.team.net 
> <mailto:healeys-bounces at autox.team.net>> *On Behalf Of *richard mayor 
> via Healeys
> *Sent:* September 19, 2021 7:52 PM
> *To:* Michael Oritt <michael.oritt at gmail.com 
> <mailto:michael.oritt at gmail.com>>
> *Cc:* Healeys <healeys at autox.team.net <mailto:healeys at autox.team.net>>
> *Subject:* Re: [Healeys] New clutch query
>
> My first thought was that if you were having to force the gearbox when 
> it was 3 to 4 inches away from home, it may be the spines in the 
> clutch disc and the input shaft were causing some interference.  This 
> should have been an easy slip fit.  Did you lubricate the spines?  
> Test fit the disc on the input shaft? Installing a gearbox should not 
> be a tedious affair.  Or, you did not get the disc properly aligned 
> using the little plastic tool.  There is a lot of wiggle room for 
> error. I've found that an old input shaft works better than the 
> plastic ones for getting good alignment.
>
> That brings me to my next observation. If for some reason the clutch 
> disc is hanging up on the input shaft it will not disengage as 
> smoothly as it should.  Is this your problem?  It's not clear to me 
> what you mean when you say "difficult clutch".
>
> I  have never heard of any need to break-in a clutch.
>
> On Sun, Sep 19, 2021 at 2:15 PM Michael Oritt via Healeys 
> <healeys at autox.team.net <mailto:healeys at autox.team.net>> wrote:
>
>     Simon--
>
>     I cut the head off one bolt to make it easier to R&R the secondary
>     cylinder. I also fashioned a small door in the extension panel to
>     give access to the bleed nipple from inside rather than only under
>     the car.
>
>     Best--Michael Oritt
>
>     On Sun, Sep 19, 2021 at 4:23 PM Simon Lachlan via Healeys
>     <healeys at autox.team.net <mailto:healeys at autox.team.net>> wrote:
>
>         You’ll recall the Overdrive saga. Have decided not to
>         commission  a TV mini-series per someone’s advice.
>
>         1) The overdrive is in and works very well. I haven’t tested
>         the pressure yet – I will – but it clicks in and out very briskly.
>
>         2) The new clutch kit is in. Hard to get the old bits off
>         until I borrowed that magic tool. Used the black nylon(?) tool
>         from AHSpares as so much handier than the spare original shaft.
>
>         3) Putting the gearbox back in was pretty tedious. It would go
>         in all the way except for the last 3 or 4 inches. Took it out
>         again and checked the alignment was 100% which it was. Put it
>         back in, pushed, shoved and cursed. In the end we wound it on
>         with long threaded bolts. I don’t want to put in another
>         clutch. Ever.
>
>         4) Now, finally, the QUESTIONS:-
>
>         Initially, getting the car into any gear was very graunchy and
>         really the car would have been undriveable. Pedal pressure
>         felt the same as before but nothing was happening except
>         expensive noise.
>
>         Although there was no evidence of a loss of fluid – why would
>         there be? – I bled the clutch. I have fitted the extension
>         tube so it wasn’t tricky. That did make a difference but not
>         to the way it was previously.
>
>         So (1) Is it normal for clutches to be difficult at first? A
>         sort of “breaking-in” period??
>
>         (2) I’ll bleed it again but am drawn to getting a longer push
>         rod for the slave cylinder. Does that make sense? I do have to
>         push the pedal down pretty far. Comments?
>
>         (3) Slightly off topic……digging around in my files, I saw a
>         suggestion to cut the head off the top bolt that locates the
>         slave cylinder. Then to Loctite in permanently for use as a
>         dowel peg. ie that bolt is a bit of a PITA and one bolt would
>         suffice. Wouldn’t it??
>
>         All advice would be very welcome,
>
>         Simon
>
>

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