Could be electrical, and should be the first thing to check anyway. Unfused
ignition (white) is fed to the manual switch on the dash, which feeds it
down on a yellow (my diagrams show it changing to a yellow/red at a bullet
connector) to the lockout switch on top of the gearbox, which when in 3rd
and 4th feeds it on a yellow/purple to the solenoid. I would be surprised
if that amount of oil made the difference between working and no-working, so
it (the problem) may come back. If you can cause it to switch in and out
just by pulling the lever around when in 4th it is almost certainly either
the switch on top of the gearbox being loose or worn, wear can be
accomodated by removing one of the shims. On the other hand if that amount
of oil *does* make the difference, then I would imagine there is something
marginal inside the o/d.
----- Original Message -----
From: "Mark Smith" <firstname.lastname@example.org>
Sent: Sunday, February 10, 2002 9:37 AM
Subject: Re: Overdrive problem.....
> Gurus of the MG list.....
> Whilst out motoring today my overdrive started dropping in and out. I'd
> blasting around for a few hours when this malady occured....The car was
> sitting at about 60mph and would suddenly drop out of O/D then back in. I
> tested it a couple of times with no ill effects. It proceeded as
> or another half an hour then dropped out and this time refused to come
> Consulting the trusty workshop manual revealed dire warnings about
> engines to access O/D units and the like..You know the sort of scary stuff
> you dont do unless you really have too. Anyway I noticed in the
> troubleshooting section a mention about checking the gearbox oil level as
> this can have a bearing on the operation of the O/D..Sure enough the level
> was a tad low.......I filled it up...adding about 300ml and its now
> fine. My question is in your collective experiance have I solved the
> or is there a serpent lurking in my gearbox waiting to strike my
> The car is a 68 MGB Mk1.....
/// email@example.com mailing list
/// or try http://www.team.net/cgi-bin/majorcool