auto trans problem

Hello All,

I've got a 90' 740 GL (automatic transmition) and it all has just
over couple of hundred thousand miles. It seems to be shifting good
normally but every once and a while it just shifts down like you have pushed
the O/D button into the off position, on it's own. The light comes on that
is on the dash to indicate it has been moved but I have done nothing with
the button. But I push the button and it shifts into O/D and continue on.
I'm afraid I will damage the tranny if this continues so if anyone among you
have seen or had this happen and can tell me how to correct this I would
appriciate it very muchly.

Bruce

 

It won't harm the transmission. The O/D relay's gone flaky.

Bob

 

http://www.brickboard.com/FAQ/700-900/TransmissionAuto.htm#AW7071OverdriveRelaySwitch

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

More likely that the kickdown wire has come out of adjustment or you are
being a little leadfooted when driving.

Cheers, Peter.

 

Thanks to you all for this valuable information, I'll check the wiring and
the relay out asap and let you know which problem it was. Thanks again!
Bruce

 

there is an orange arrow on the dash pointing upwards . does this arrow
flash unexplainably ? if so that means the transmission has a code in it and
needs to be tended to

 

<snipped>
Not on a 740!! There are no codes storable as transmission is purely
mechanical.

Cheers, Peter.

 

Peter, the arrow on the dash does come on when it unexplainably shifts down
but there has never been any blinking of the arrow that I have noticed.

Bruce

 

You've got a bad connection inside the overdrive relay. If you can solder
it's easy to fix, otherwise a new relay is about $50 and is easy to change
out.

 

That was it I guess, I heated up one spot that looked bad on the board and
it hasn't done it since. Thanks, Bruce