1969 L89 with automatic

[Steven B.]

Re: 1969 L89 with automatic

I had a 1969 Camaro 396/375 HP auto. The heavy duty transmission was mandatory When you drive one there is no doubt that its a different one than the standard. Damn thing was scary the way it shifted. I assume the Corvette used the same one.

Right you are Ken. In college I had a couple of friends who bought '69 375 HP Camaros. One ordered the auto and the other bought a 4 speed off the floor. The guy with the auto wanted to add a shift kit and at the time the J&G Speed Shop told him it was not the "normal" TH400. It shifted like it had a kit right off the truck.

Steve

[Ronald R.]

Re: 1969 L89 with automatic

Ralph's car was one of the last 69CY, do you have the SN?

[Ralph S.]

Re: 1969 L89 with automatic

My 1969 Corvette is VIN #38161 Q11 12.11.69

[Richard M.]

Re: 1969 L89 with automatic

Another interesting piece of info. about the CY 400:


Concerning the CY transmissions that came in the Gibb Nova's, there was a special bulletin sent out to GM dealerships dated July 12, 1968. It reads:

NEW HEAVY DUTY TURBO HYDRA-MATIC TRANSMISSION

A new heavy duty or "high speed" version of the Turbo Hydra-Matic transmission will be available with the 425 HP 427 V-8 for Chevrolet models, the 396 375 HP Chevelle, Camaro, Chevy ll's and the 430 and 435 HP V-8 Corvette's. Previously only manual transmissions were available with these engines. The new transmission includes modifications to accept the greater engine torque, higher RPM, and generally more rigorous operation anticipated with these high output engines.

To accomodate engine speeds up to 7800 RPM, 1600 RPM higher than normal operational speeds, a special torque converter assembly is used, with all pump and turbine blades welded rather crimped in place. The converter assembly is bolted to the engine flywheel at six points, double the number of the standard unit.

Because of the higher torque loads experienced during hard acceleration, premimum quality driven plate facings are used in the intermediate clutch, which is applied to accomplish the 1-2 upshift. Firmer upshifts are obtained through modifications to the accumulators in the itermediate 1-2 and direct 2-3 clutch apply circuits to reduce cushioning action. Govenor calibrations are also revised to raise the maximum upshift point from 5100 to 6300 RPM.

All other design details, including converter ratio and gear ratios, are common with the Turbo Hydra-Matic use with regular high displacement engines.