I've had a problem selecting certain gears on my Focus for a while now.  I
think something in the linkage is broken rather than a problem with the
gearbox itself - when selecting 2nd, 4th and reverse (i.e. at the
'bottom') it feels like there's something loose/broken and getting in the
way.  At times these gears are completely unusable only to be fine the
next day. It's as if the lever is only barely moving far enough and is not
quite engaging properly.  1st, 3rd and 5th work perfectly all the time.
Can't get any sense from mechanics at dealers - it never has the problem
when I take it in and they say they need to take it apart to look and
that'll cost a fortune even before parts.  Don't want to be ripped off as
I think it's just something broken/bent (hopefully something cheap!)
especially due to it only being intermittent.
Anyone had similar problems?
Sorry for the non-technical description - I'm a bit out of my depth when
it comes to this stuff.  Can anyone point me to a site that explains to
the layman what happens between gear-knob and gearbox?

ok,  what year focus is it?

a common problem with the early focus(before 2002 ish) is the neutral gear
spring snapping, only costs about 3 quid for the part and about 1/2 hour to
renew, its under the gear lever gaiter a bit fiddly but can be done

at the front of the  gearbox (looking from underneath)there's a black
cover, inside here is where the gear shift cables are attached, check
these for seizing and correct movement could be a cable problem and not
inside the 'box

Thanks - it's an older one - 1999 and yep, the return spring snapped when
it was about a year old.  That was never a problem until recently though -
just meant you had to be careful not to select first instead of third!
About a year ago I actually heard something 'snap' when making a quick
gear change and that's when the problems started. Do you think this could
have been caused by the lack of return spring?  A few people I've spoken
to reckon this is the problem, but I'm sure there's more damage - probably
as a result of me not getting it fixed back then.