[Healeys] Overdrive pressure or clutch slip Step 2!

[Michael Salter]

Question  ... when you got home and did the pressure test I presume that
was AFTER you had put the valve with the "top hat", ball, spring and valve
rod cap and washer back into position?

M



On Thu., Apr. 25, 2024, 12:29 p.m. Simon Lachlan, <
simon.lachlan at alexarevel.plus.com> wrote:

> So, here is Michael’s “Step 1” completed. (See his email, below).
>
>    1. Removed the operating valve and, just for luck, disconnected the
>    two wires into 3rd/4th switch. Took the car for a spin. Up/down
>    longish/steepish hills, 10 miles on motorway. Various rpm…..no slippage at
>    all.
>    2. Had a puncture…..nail in tyre. Rear RHS. Flat as a pancake at once.
>    Nearly onto rim. Nail! I imagine the inner tube is shredded and the tyre
>    may be a write-off. (Usually are!). Anyhow, I bore you with this as I’m
>    convinced that I’d never have got the wheel off without the little scissors
>    jack which I carry to get the car up the first few inches until the Healey
>    jack comes into play. Just a suggestion…….
>    3. Got home and jacked car up to test pressure. Steady at 520psi
>    which, I recall, is plenty. Stayed at 520 across rev range. Dropped very
>    slowly once engine was off and dropped to zero as I engaged/disengaged OD a
>    few times. Which is normal I think?
>    4. Solenoid makes a robust “click” when it should and engages the OD
>    when activated.
>
> So what’s a sensible “Step 2”??
>
> I have been urged to check the setting of the Throttle Switch (TS).
> Assuming that the slippage returns (and why wouldn’t it?), I’ll short the
> TS out to see if that fixes it. If it does, I’ll check the adjustment.
>
> Suggestions would be more than welcome……I do dread having to take that box
> out again. I’ve got a very adequate ramp and a very strong volunteer(?)
> but, regardless of all that, it’s still quite a task. And, like a few of
> us, I’m not as young as I once was. I’ve always enjoyed the lines from the
> manual which I reproduce, below. “Gently ease”!?!
>
>
>
> Thanks, Simon
>
>
>
> *From:* Michael Salter <michaelsalter at gmail.com>
> *Sent:* Monday, April 22, 2024 3:21 PM
> *To:* Simon Lachlan <simon.lachlan at alexarevel.plus.com>
> *Cc:* Healeys <healeys at autox.team.net>
> *Subject:* Re: [Healeys] Overdrive pressure or clutch slip
>
>
>
> *Correct diagnosis is 1/2 the repair!!*
>
>
>
> First you need to confirm whether the clutch (on the flywheel) or the
> overdrive is causing the slippage.
>
> To do this you ABSOLUTELY MUST disable the overdrive as a badly
> misadjuster overdrive operating valve can produce similar symptoms.
>
> To do this I would remove the overdrive operating valve completely. (There
> are other ways but this is absolutely definitive).
>
> Now drive the car up a long hill where you are amle to use full throttle
> at around 3000 RPM (maximum torque) for a few seconds. If it is the clutch
> (on the flywheel) that is causing the slippage these operating conditions.
> Test this a few times to be sure.
>
> If there is no slippage we have confirmed that the overdrive clutch is at
> fault.
>
>
>
> Step 1 completed. Please report results. MS.
>
>
>
>
>
>
>
> On Mon., Apr. 22, 2024, 8:08 a.m. Simon Lachlan via Healeys, <
> healeys at autox.team.net> wrote:
>
> You may recall the very extended overdrive and clutch saga last year. Long
> story short(ish)…
>
> OD was slipping in and out depending on oil temperature.
>
> Correctly diagnosed pressure. Checked with gauge.
>
> Attempted rebuild…going only so far as accumulator and related seals.
>
> Stymied as could not get pump out. Turned out to have been “fixed” at some
> stage with some form of “chemical metal” which was coming loose/apart.
>
> Took it up to OD Spares who fixed it..new housing etcetc
>
> Why not a new clutch I thought? Sensible while you’re in the area looking
> at a 30+ yr old item.
>
> New clutch…no good. Noisy, wouldn’t engage/disengage/play at all.
>
> Gearbox out again.
>
> Refit clutch. Presumed I’d made some beginner’s mistake.
>
> Refit gearbox…no good. Same
>
> Can’t recall whether I tried again. Lost count and enthusiasm by now.
>
> Turned out that the new clutch kit was defective. (Thanks Mirek) (Genuine
> B&B from AHSpares).
>
> New one did work.
>
> Saga over until yesterday.
>
> Same sort of symptoms…..
>
> All’s well for first 10 or so miles. Then the dreaded slippage(?) starts.
> But it’s not quite the same. Reminds me more of a slipping clutch. (But NO
> smell)
>
> Symptoms continue if it’s in or out of OD.
>
> Symptoms reduce at speed.
>
> Yes, plenty of oil. Over the full mark. Looks very clean. Pretty sure it’s
> 40wt non-detergent topped up with 30wt non-detergent. (Or vice-versa). Am
> confident in state of the filter, magnets etc.
>
> No, I have not pressure tested it yet and yes, I dread restarting the
> whole bloody process all over again. I’m not sure I can face taking the box
> out again once, let alone multiple times.
>
> What I want and experience tells me I’m unlikely to get is a miracle cure!
>
> One initial question…..do OD relays either work or not work? ie, can the
> relay hover between on and off which might lead to the OD coming in and
> out? I think that could happen if the switch is off but the unit still
> hasn’t got the message to disengage from the bulkhead switch.
>
> And a supplementary….how do I bench test the relay?
>
> Simon
>
>
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