[Healeys] Transmission?

[Fred Wescoe]

Listers,

Last week I backed my BJ7, with overdrive, out of the garage and got a
short sound of scream/grind from what I thought was the rear end.  I pulled
back into the garage.  I drained the transmission and overdrive oil as well
as the differential oil thinking either could be low and in need of a
change.  I pulled an axle and checked it.  Nothing apparent.  No oil
showing on the brake drums.  I checked the u-joints and there was no
looseness seen.

I refilled the transmission, overdrive and axle with Red Line oils.  The
car was on jacks all the way around.  I started the engine and let it warm
up and then put it in gear.  I tried 1st, third and reverse.  No sounds of
problems with or without the overdrive switched on.

This morning, I backed out of the garage and went a few miles.  I stopped
at a friends home to pick up something.  Put the car in reverse and
instantly got the scream/grind sound.   I made sure the overdrive was
switched off and tried again with the same results in both reverse as well
as all forward gears.  I turned the car off and tried again, this time no
sound.  I drove the car home with no problems.

What do I start looking for?  Is it possible that the overdrive is not
disengaging even with the switch off?

Help!

Thanks in advance,.

Fred