[Healeys] Overdrive solenoid

[Earl Kagna]

Piet:

I've had this happen a couple of times.

Turned out to be the gearshift lever switch on the transmission - the one 
that allows the overdrive to work only in the 3 -4 position.  The switch 
would engage - but barely - when the transmission was cold and then either 
drop out, or go in and out when everything warmed up.  The test for me was 
to apply momentary pressure to the shift lever (to the right I believe - it 
was a long time ago).  If the overdrive then shifts back in and holds, 
simply adjust the switch at it's mount by re-shimming it so that it's closer 
to the activation point so it closes reliably when the lever is in the 3-4 
position.

If this turns out to be the cause, you'll probably notice a wear spot on the 
ball end of the switch.  You haven't stated which Healey model you are 
referring to, but the situation can happen on either the side or top-shift 
transmissions.

Worked for me!


Earl Kagna
Victoria, B.C.
BJ8, BT7 tri-carb

-----Original Message----- 
From: Pieter and Linda
Sent: Monday, October 03, 2011 7:33 AM
To: Healey List
Subject: [Healeys] Overdrive solenoid

Hi Guys,
I have a perplexing problem with my overdrive. It is in good condition with
upgraded clutch, accumulator etc. It engages quickly but after a few minutes
of driving it starts to jump in and out of overdrive. I don't have a 
throttle
switch fitted. My only suspect it the solenoid. Since there are 2 windings,
one to engage the overdrive and one to keep it engaged, could it be that the
internal switch or winding fault is causing it to "drop out" and then the
stronger winding immediately re-engages the overdrive? Opinions?

2nd question is the replacement solenoid. There seems to be a wide variety 
of
prices for this part from all the usual suppliers. Are solenoids all the 
same?
Can anybody recommend which to buy or which to avoid?

Thanks as always,
Piet