Automatic transmission doesn't change-up

Dear Sirs, my Volvo 940 - 1994 automatic transmission was recently
serviced and a new gasket kit replacement done and oil filled. However,
now the automatic gear doesn't change-up. It sticks in the 2nd gear only.

The workshop is now recommending a transmission box overhaul!

Need your help. I want a checklist or a guide to go thru with the
mechanic before I spend anymore money.

Any assistance is appreciated.

thanks.

 

First make sure that the fluid level is correct. Then look at the cable
that leads from the throttle pulley down to the transmission - if
there's any slack that'll be your problem.

--
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.)

 

In an earlier contribution to this discussion,

Surely a slack cable would have the *opposite* effect - by causing the
tranny to hold onto *higher* gears, and not change down when required?

The fault-finding chart in VADIS suggests problems with either the governor
or a sticking 2-3 shift valve - both of which are hydraulic devices. I'd put
my money on your 'workshop' having got some crud mixed up with the oil. Do
they know what they're doing? Unless you're totally confident in them, I'd
take it to an expert - and then invite the original outfit for pay for the
remedial work necessitated by their efforts!

 

Opening the throttle pulls the cable out of the transmission. If the
cable sticks (the return spring inside the transmission is not very
strong), then the part of the cable near the throttle pulley is very
slack at idle. Then the transmission "thinks" that the engine is
running at a high power setting, and delays upshifting. At light
throttle, it seems that the transmission won't upshift.

--
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.)

 

In an earlier contribution to this discussion,

Sorry! See what you mean! I thought you were talking about a cable which was
slack because it was incorrectly adjusted - in which case what I said would
be true.

 

Dear Sirs, thank you for your comments. It seems I still need your valued
assistance...

The problem started when I was driving my car and started losing 'drive'.
The car was acting like the 'worn out clutch' in a manual car. It was
making a whining noise and it was slowing down going up inclines. I got
worried so I pulled over. When I stopped the car, I found that I had to
rev really high to move the car again. So I shifted to N, waited for a
minute, shifted into D, the car was not moving at all. I was on flat road.

I was really worried. I had not replaced the transmission oil in a while
although I checked that the oil level was OK. After I waited for about
half hour, I started the car, shifted into D and it moved normally. I
drove to a service outlet nearby and had them replace the transmission
oil. I drove away and about 3 km away the whining noise started again
going up a gradual incline and I started losing 'drive' again.

I drove the car home and the next day being a Sunday, relatively traffic
free. I drove the car over to the mechanic's workshop. By the time I was
reaching the mechanic's workshop about 15 km away the transmission was
acting-up again.

The mechanic mentioned that oil might be 'dirty' and he will need to
service the valve body. Servicing the valve body means that he will need
to replace the gaskets, so the gasket kit was purchased, replacement done
and new oil filled.

I went to him with your suggestions. He promptly informed me that he has
replaced the transmission oil and that in fact no matter the rev, the gear
doesn't up-shift from 1st gear and not 2nd gear as earlier mentioned.

Any advice is appreciated.

thanks.

 

I don't think there's any doubt now... you need a new transmission.
There are dozens of good used ones around.

--
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.)