[Healeys] FW: Overdrive pressure or clutch slip

[Simon Lachlan]

Should have added to all below
..electrics seem to pass the test which I
quote below:-
1. Make sure battery switch is ON and battery is charged.
2. Make sure overdrive dash switch is in OFF position. 
3. Turn ignition switch ON (but don’t start the engine). 
4. Keep your foot off the throttle.
5. Wiggle the gearshift, making sure you move it fully to the right each
time. You should not hear the solenoid actuate.  (If you do, see Note 1.) 
6. Move overdrive dash switch to ON position.  
7. Wiggle the gearshift - you should hear the solenoid engage and disengage
with each wiggle.  (If you don’t, see Note 2.) 
8. Depress the throttle about ½ way and hold. Wiggle the gearshift - you
should still hear the solenoid engage and disengage with each wiggle.  (If
you don’t, see Note 3.) 
9. Take your foot off the throttle. Move the overdrive dash switch to OFF.
Wiggle the gearshift - you should still hear the solenoid engage and
disengage with each wiggle.  (If you don’t, see Note 4.) 
10 Slowly start depressing the throttle while wiggling the gearshift at the
same time.  You should initially hear the solenoid engage and disengage
until the throttle reaches approximately 1/5 open position (workshop manual
spec.).  Then, while continuing to wiggle, you should not hear the solenoid
regardless of the throttle position.  (If you do, see Note 5.) 
If your car passes this test, your overdrive electrical system is OK.  If
not, the following notes, related to the Steps above, may be helpful.  
(Test, above, is an abbreviated version of, I think, Bob Poague’s work.) Not
thought out by me but used often enough to trust it.
Simon





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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