1958 & 1959 Triple Turbine to Twin Turbine Conversion Kit

[Glassesguy]

I seem to recall the question had come up on the Forum at one time whether Buick issued a factory kit to convert a Flight Pitch or Triple Turbine equipped car to a Twin Turbine transmission. This should answer the question.
This is from my 1940-63 Chassis Parts Book.

Gr 4.005 All 1958 Part # 1396090 "Kit,3T Trans To 2T Conversion Parts".

Gr. 4.005 All 1959 Part # 1396091 "Kit, 3T Trans To 2T Conversion Parts".

Unfortunately there is no listing as to what the kit contained. The 58 kit was priced at $27.50 while the 59 kit was priced at $20.00. My guess would be a different stator and throttle linkage, shift dial indicator, and transmission mount hardware recalling my past experience doing one.

There is nothing like driving a Flight Pitch equipped car. Have yours rebuilt instead of converted if at all possible. Jim Hughes, BCA member here in Perrysburg does a superb job and is very knowledgeable on the trouble prone items.

[MartyWorld]

How does a triple turbine equipped car drive differently
than a twin turbine equipped vehicle? Take off? Passing
ability? With a twin turbine shifted into "low", would it
outperform the triple turbine?

Thank you,

Marty

[Glassesguy]

Marty:
Your question had forced me to really think about how to describe the differences. I have driven Limiteds with good Flight Pitches and two Limiteds that had been converted to Twin Turbines. Any of the Dynaflows are incredibly smooth as there is no mechancial step shifting as in other makes of transmissions. Yes, there are clutch packs in a Dynaflow but it is in the torque converter where the changes occur. The biggest thing that struck me about a Flight Pitch is you've got to be aware of at what speed you want to be cruising and back off on the pedal. These transmissions are so smooth that if you don't pay attention and the sensation of motion is so muted in these cars, that it's easy to be going faster than what you wanted. Twin Turbine not too far behind on this, but its slightly different "gearing" due to 2 forward speeds is slightly less motion isolated. Regarding the 2T engaged in Low vs 3T performance, I've never put a stop watch to this. The feeling off the line in "Low" is definitely stronger on the 2T due to the mechanical engagement vs the total hydraulic engagement of the clutches on the 3T. Many people misused the "G" range on the Flight Pitch as they assumed it was a "Low" gear range; however "G" was designed to be used on downgrades only. Chevy Turboglides faced problems here as well. Ya just gotta drive one!!

[MartyWorld]

Dave,

Thank you for your response. Why did Buick discontinue the
flight pitch in the 59 model run? Did Buick develop the
trans or Chevy, since the Turboglide is very similiar in design?

Thanks again,

Marty

[Centurion]

Marty, since we developed the '59 Buick website a couple of years ago, I have been quite surprised by the number of Triple Turbine '59 Buick survivors that have turned up. On Memorial Day weekend, we gathered five '59 Buicks at a local show in Bellingham, Washington, and it seemed quite remarkable to me that three of the five cars were Triple Turbine-equipped.

Dave's comments are certainly accurate regarding the performance of the Triple Turbine. I recently drove a fine, original '59 LeSabre with the regular Twin Turbine, so could compare its performance to that of my Triple Turbine. As some have written in these forums during the past, the Triple Turbine is a dream to drive when set up properly.

It is my understanding that Buick developed the Flight Pitch / Triple Turbine at great cost, but the Dunham / Gustin book on Buick history indicates that the transmission was really a corporate idea. The Chevrolet Turbo Glide was apparently derived from the Fight Pitch / Triple Turbine, but the Buick tranmissions utilized cast/machined components whereas the Chevy transmission utilized stamped/welded components. A mechanic friend of mine who has worked on these cars indicates that the Flight Pitch was clearly built with the intention that it would last for the life of the car, but says that the cheaper materials in Chevy's Turbo Glide almost ensured its failure.

Why was the Triple Turbine discontinued during the '59 model year? I can only offer a few theories, but I have heard that the transmission was significantly more expensive to manufacture. And, since it was difficult for most buyers to grasp the benefits of 3T, the option was not very popular. Problems with the early '58 Flight Pitch transmissions and the aforementioned danger of accelerating in the "Grade" range probably doomed the transmission's reputation.

1958 and 1959 were weak sales years for Buick, so, ultimately, it made little sense to offer two automatic transmissions that were completely unique to Buick.

[Glassesguy]

Marty:
Brian's comments echoed my thoughts and understandings on why Buick did what they did. The Flight Pitch was very expensive and really did not yield that great of a benefit to the customer. Too many troubles and weak sales probably doomed it. I've never driven a 59 3T. The transmission itself did differ from the 58 version as the 59 eliminated the rear pump. I'm curious if that made a difference in driving a car so equipped. Driving a 58 I always had the sensation that when you reached cruising speed and backed off the gas, the rear pump "caught up" with the front pump.
Whether or not that is true it just felt like it. Would be curious if 59 3T feels different. By the way you can identify a 59 3T from a 58 by the number of external plugs for testing oil pressures at various points. The 59 has fewer. The transmissions themselves interchange as complete units. The Buick Parts Product Bulletins so say.

[MartyWorld]

Dave and Brian,

Thank you for your responses.

Looking at the "flight pitch" manual for 1958 and the
Buick chassis manual for 1959, there is a difference in
starting torque; 58/4.5 and 59/4.7. Probably not much difference as far as "seat of the pants" response, although
pure speculation. I also wonder how that change occured since the gear ratios did not change from 1958 to 1959.

Thanks again,

Marty