Transmission –
The 700R4 transmission is a fully automatic 4 speed transmission with a lock up torque convertor that, when engaged, locks the transmission completely and gives the same fuel economy and performance as a car with manual gears.
During the life of this transmission various updates were made correcting problems as they were discovered. With these updates the 700R4 is a strong and reliable transmission.
I think the Corvette auto transmission is brilliant. The shifts are so smooth it’s hard to know they’ve happened. The 4th gear is called overdrive, it’s a big gear designed for high speed although it will lock in with light throttle at a low 61kph. At this speed the revs of the big V8 motor drop to just above idle – incredible ! This gear is a real help to the fuel economy, compared to the previous C3 Corvette Stingray’s which only have a 3 speed auto transmission.
I discovered information about the update kits and decided that it would help keep the transmission healthy for a long life. I researched the various update kits and found one that was highly recommended by Corvette enthusiasts – the Transgo Shift Kit. This comes in 3 stages covering everything from normal street driving to drag racing with high horsepower engines. I didn’t want to loose the super smooth shifts so I had the normal street driving kit – SK 700 fitted at the next transmission service in March 2004.
Dave at GTS, 145 Scott St Cairns fitted the kit and gave the entire transmission a service, including inspecting U joints etc. There was an instant ‘seat of the pants’ feeling of improvement when I drove away afterwards. Hard to explain, the shifts are still super smooth but also firmer. I was very happy.
Unfortunately during the next few months the transmission began to show signs of some internal damage. I decided to have the gearbox completely rebuilt by a recognised expert on these transmissions – Neil Maxwell of Precise Automatics, Beenleigh, Qld.
I sent my Corvette down to him by road transport and he did a full recondition on the transmission, including installing a heavy duty drive shell, rebuilt pump, etc and set the valving up so that the gearbox shifted smoothly at low revs and firmly at high revs.
Neil said the new transmission was ‘better than out of the factory’ and should last a long time
January 4th, 2011 at 9:26 pm
Hi Rob,
Thank you for sharing your rebuild experience with the C4 Automatic transmission. I believe mine is still factory original. Thanks also for the TV Cable adjustment advice too. For other C4 folks with the automatic transmission out there, do not mess around with your TV cable. If you have messed around with it, I would reset it ASAP as per the factory manual.