Strange and mysterious transmission issue....

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wirry1423

Hello again. I wanted to take a moment to post about an od
transmission "event" which happened a couple of months ago. Backgroun
info: I have a 1986 Volvo 240 DL sedan with an automatic aw7
transmission. The tranny was rebuilt in early 2002 due to damag
caused by "rocking" the car out of a snow drift, as well as lack o
servicing (I acquired the car in 2000). Since the rebuild, th
transmission has functioned perfectly (with one exception) other then
dead overdrive relay which I have just replaced successfully, and I hav
had regular transmission servicing. However, two months ago, I wa
driving on a city street. I fully stopped at a red light and wa
waiting for it to turn green, when without warning, the alternato
died. I put the car in neutral and pushed it to the curb, then put i
in park while i waited for the tow truck. I had the car towed vi
flatbed tow truck (with it in neutral for the tranfer onto and off th
truck) to the shop. The shop also had to put it in neutral to push i
from the parking spot into the bay. According to my dash clock, th
battery was disconnected for over two hours while they worked. When
picked up the car, everything was apparrently fine. But as I drov
home, my heart sank when the car failed to shift into third gear at it
usual 27 mph. It shifted into reverse, park, first gear and second gea
absolutely fine, but would not go into third gear. I even drove it u
to 50 mph to see if i could force it into gear all to no avail. Nex
morning, I took it back to the shop. All told I drove it for over on
hour at various speeds and turned it off and on without it shiftin
into third once, but all other shifting was fine. When I took it back
they asked about the tow truck (flatbed with car in neutral) and the
asked if i was moving when the alternator failed (I was not). Th
mechanic then asked to take it for a test drive with me as passenger.
We drove for the first couple minutes without it shifting into thir
gear. But after some hard accelerating along with the mechani
shifting from drive into 2 and 1 climbing gears, the car finally poppe
into third a little late and with a little thud. After the first time
it shifted into third and back for the rest of the ride normally. The
then checked the fluid, which was fine. They said they did not kno
what happened, but that maybe the computer reset itself. I though
that the alternator failure caused a solenoid to short out (but tha
was not it because the car did shift after some time) Since thi
incident several months ago, the car has shifted absolutely normall
with not one problem. I even recently changed out the OD relay (whic
had died several years ago) and it shifted into OD like norma
immediatly. My question is what do you think caused the car not t
shift into third gear for that first day after the alternator repair?
I am simply very curious and frankly still a little concerned. Than
you very much for reading that lengthy post and for any thoughts yo
can provide
 
wirry1423 said:
Hello again. I wanted to take a moment to post about an odd
transmission "event" which happened a couple of months ago. Background
info: I have a 1986 Volvo 240 DL sedan with an automatic aw70
transmission. The tranny was rebuilt in early 2002 due to damage
caused by "rocking" the car out of a snow drift, as well as lack of
servicing (I acquired the car in 2000). Since the rebuild, the
transmission has functioned perfectly (with one exception) other then a
dead overdrive relay which I have just replaced successfully, and I have
had regular transmission servicing. However, two months ago, I was
driving on a city street. I fully stopped at a red light and was
waiting for it to turn green, when without warning, the alternator
died. I put the car in neutral and pushed it to the curb, then put it
in park while i waited for the tow truck. I had the car towed via
flatbed tow truck (with it in neutral for the tranfer onto and off the
truck) to the shop. The shop also had to put it in neutral to push it
from the parking spot into the bay. According to my dash clock, the
battery was disconnected for over two hours while they worked. When I
picked up the car, everything was apparrently fine. But as I drove
home, my heart sank when the car failed to shift into third gear at its
usual 27 mph. It shifted into reverse, park, first gear and second gear
absolutely fine, but would not go into third gear. I even drove it up
to 50 mph to see if i could force it into gear all to no avail. Next
morning, I took it back to the shop. All told I drove it for over one
hour at various speeds and turned it off and on without it shifting
into third once, but all other shifting was fine. When I took it back,
they asked about the tow truck (flatbed with car in neutral) and they
asked if i was moving when the alternator failed (I was not). The
mechanic then asked to take it for a test drive with me as passenger.
We drove for the first couple minutes without it shifting into third
gear. But after some hard accelerating along with the mechanic
shifting from drive into 2 and 1 climbing gears, the car finally popped
into third a little late and with a little thud. After the first time,
it shifted into third and back for the rest of the ride normally. They
then checked the fluid, which was fine. They said they did not know
what happened, but that maybe the computer reset itself. I thought
that the alternator failure caused a solenoid to short out (but that
was not it because the car did shift after some time) Since this
incident several months ago, the car has shifted absolutely normally
with not one problem. I even recently changed out the OD relay (which
had died several years ago) and it shifted into OD like normal
immediatly. My question is what do you think caused the car not to
shift into third gear for that first day after the alternator repair??
I am simply very curious and frankly still a little concerned. Thank
you very much for reading that lengthy post and for any thoughts you
can provide.
It sounds like a fairly common problem; a sticky or otherwise deranged
kickdown cable. More often it manifests itself in all gears, but it can
certainly show up just in certain ranges - more commonly in the lower gears.
Essentially, it fools the transmission into thinking the throttle is open
wider than it really is.

Open the hood and (with the engine off) rotate the throttle wheel where the
cables wrap around it, by just rotating the wheel while watching the cables
where they wrap around the wheel. If you have cruise control, two will wrap
one way and one will wrap the other - you are interested in the one that
wraps the other way. If no cruise control, watch the one that tightens as
you open the throttle. That one is the kickdown to the tranny. It should
move smoothly and not try to ride up as you open the throttle. A squirt of
graphite into the cable can't hurt. But from your description I'd guess a
bit of debris got in the way when the alternator work was done and it
eventually fell out, or the cable was misaligned (same cause) and eventually
popped back into place.

Mike
 
Thank you for replying. The Kickdown cable also came to mind when th
event occurred. I actually remember mentioning the KC to the shop whe
I brought the car back, just before the test drive. The mechanic wasn'
sure, but the owner of the shop thought that it was a possible culprit
I just finished checking the cable and it seems tight and well aligne
from my inspection of it. Is there any possibility that my driving fo
that day with the Kd cable out of shape/misaligned caused any long ter
tranny damage, or am I in the clear now? Thanks again for th
response
 
wirry1423 said:
Thank you for replying. The Kickdown cable also came to mind when the
event occurred. I actually remember mentioning the KC to the shop when
I brought the car back, just before the test drive. The mechanic wasn't
sure, but the owner of the shop thought that it was a possible culprit.
I just finished checking the cable and it seems tight and well aligned
from my inspection of it. Is there any possibility that my driving for
that day with the Kd cable out of shape/misaligned caused any long term
tranny damage, or am I in the clear now? Thanks again for the
response.
No damage from that, it just confuses the shifting for a while. The AW-70 is
a remarkably rugged tranny so I think you are out of the woods.

Mike
 
Thanks, thats kinda what I thought, but i just wanted to get anothe
opinion on it. No-harm-no-foul I guess. Take care
 
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