63 LeSabre...transmission doesn't kickdown?

96roadmaster · 2 Weeks Ago

Our 63 LeSabre doesn't want to downshift on the 2-1 shift at WOT at any speed. It's a 4 Barrel car (factory option), carb was just rebuilt and is 100%, yet the car won't shift down at any speed. It used to shift down up until a couple months ago. The car has 12k miles on it.

Any ideas anyone can throw at me?

Pete Phillips · 2 Weeks Ago

Please explain how a 2-1 downshift is supposed to occur on a Turbine Drive or Dynaflow transmission. That is news to me. You have enough Dynaflow-equipped Buicks that you must know what you are talking about. I've owned and driven about 20 Dynaflow-equipped Buicks and never heard of a downshift on one of those, other than manually shifting the lever from D to L.
Pete Phillips, BCA #7338
Sherman, Texas
1948 model 71
1949 model 59
1950 model 76-R
1959 Electra 2-dr.
1962 Electra 225 4-dr. ht.
1963 Wildcat conv. 4-spd.

Centurion · 2 Weeks Ago

Pete, I was baffled by the "downshift" comment as well.

Perhaps he means that he's unable to "switch the pitch"!

96roadmaster · 2 Weeks Ago

Well yes, I wasn't thinking straight after a looong day at work yesterday. I know it's not an actual downshift but it's supposed to switch the pitch as Brian mentioned. It feels and sounds like a downshift, exactly like our '58 Super.

The '63 was fine up until a few months ago, now it just tries to pull off from a low rpm and feels like it's stuck "in gear" for a lack of a better term.

Not really an issue either way since I'm not racing it, but I'd just like all features to be working at 100%.

kaycee · 2 Weeks Ago

Hi,
Your Dynaflow trans. does'nt literally shift gears in Drive. If on heavy acceleration you 'floor it', the linkage coming off the carb. towards the firewall and down to the high accumulator on the transmission actuates the stator change in the converter(through oil pressure in the trans.), and it feels like a 'kickdown' or upshift until you let up on the pedal a bit, at which time the stator returns to normal position and it drives as if you just gradually accelerated from a stop but it does'nt 'downshift' and 'drag down' as if you manually downshifted. In Drive without really 'flooring it' you should'nt feel any shifting.
Check the linkage from the rear of the carb.( back by the firewall) down to the transmission to make sure everything is 'hooked up' top and bottom. You can tell by pulling all the way back on the throttle linkage and seeing that it works the rod in front of the firewall going down to the transmision. This linkage should be similar to all Buicks with Dynaflow back to '55 when they came out with the variable pitch stator which gave sort of a 'passing gear'.
If everything is hooked up including the 'bellcrank' on the accumulator on the trans., and you still have a problem, you probably have pressure leakage in the trans. at a gasket or valve body , so good luck.
kaycee

96roadmaster · 1 Week Ago

Quote:

Originally Posted by kaycee

Hi,
Your Dynaflow trans. does'nt literally shift gears in Drive. If on heavy acceleration you 'floor it', the linkage coming off the carb. towards the firewall and down to the high accumulator on the transmission actuates the stator change in the converter(through oil pressure in the trans.), and it feels like a 'kickdown' or upshift until you let up on the pedal a bit, at which time the stator returns to normal position and it drives as if you just gradually accelerated from a stop but it does'nt 'downshift' and 'drag down' as if you manually downshifted. In Drive without really 'flooring it' you should'nt feel any shifting.
Check the linkage from the rear of the carb.( back by the firewall) down to the transmission to make sure everything is 'hooked up' top and bottom. You can tell by pulling all the way back on the throttle linkage and seeing that it works the rod in front of the firewall going down to the transmision. This linkage should be similar to all Buicks with Dynaflow back to '55 when they came out with the variable pitch stator which gave sort of a 'passing gear'.
If everything is hooked up including the 'bellcrank' on the accumulator on the trans., and you still have a problem, you probably have pressure leakage in the trans. at a gasket or valve body , so good luck.
kaycee

Sweet. That's the type of info I was looking for. I'll give it a shot tomorrow. Thank you!!

kaycee · 1 Week Ago

Hopefully, you'll just find the linkage off at one end or the other. Again, good luck, and keep us posted.
kaycee

Patrick91914 · 1 Week Ago

Does the '63 have a vacuum modulator like the '65? If so, the vacuum line may have fallen off.

kaycee · 1 Week Ago

Hi,
No, the Dynaflow does'nt have a vacuum modulator like the later Turbo. 400's, starting in '64, and '63 was the last year that Buick had the Dynaflow. Do you have slipping in drive too, or just the problem with the 'passing gear'?
kaycee

kaycee · 1 Week Ago

96 Roadmaster,
Hi,
Did you solve the problem with your '63 transmission 'kickdown' problem?
kaycee