I’m sure many readers who worked on the tools a few years ago will have fond memories of carrying out a routine service on the old-fashioned hydraulic automatic transmission. It usually involved removing the lower pan of the transmission, adjusting the bands, cleaning the oil pump strainer, reassembling, and adding new oil.
It achieved a similar result to manually adjusting brakes. Larger clearances would develop between the brake linings and the brake drum. This meant the brake pedal would often need a couple of good pumps to restore a firm under-foot feel when the brakes were applied. After adjustment, the brake pedal would need to be applied only once to get the brakes to work effectively.
It was a similar situation with the auto transmission. Tightening up the bands, fine tuning the shift cable, cleaning the strainer and adding new oil was money well spent. It breathed new life into the transmission but, equally importantly, it gave mechanics an indication of wear and tear, which they were able to pass on to customers.
If the transmission required an overhaul, it was generally a total strip down and rebuild using readily available parts. It was a job that was a little bit specialised but one that many in-house mechanics could handle with relative ease.
Automatic specialists were (and still are) available to carry out the necessary repairs if required.
The bottom line was, most automatic transmissions were serviceable and repairable and at a reasonable cost.
In recent times things have changed dramatically, with the introduction of more electronics and the drive to reduce tailpipe emissions and fuel consumption. The automatic transmission is now a major player in achieving those reductions in mainstream passenger vehicles.
The old-fashioned hydraulic transmission was easily maintained and repaired, but it also soaked up a fair amount of lost energy as the power was being transferred from the engine to the road wheels.
Modern transmissions are more direct and operate under the heavy influence of electronics to help achieve those fuel savings and less pollution.
The industry in general is divided on which of the new generation automatics best suits their needs. Some use a Constant Variable Transmission (CVT), which is basically a varying pulley and belt/chain system. Others use a Direct Shift Gearbox (DSG), which is best described as a manual without a clutch.
Others stick with a heavily modified version of the more conventional transmission.
They all achieve their maker’s goals, but they also bring complexity to the industry and often a harsh financial burden to owners when things start to go wrong. Many manufacturers deem them unrepairable.
Servicing of these transmissions has also changed significantly. It’s basically an oil change occasionally and a scan of the electronics to ensure all is well.
So what can owners do to ensure their automatic transmissions last a reasonable distance?
Not a lot. Using genuine or manufacturer’s recommended transmission fluid is probably the most critical when a change is carried out and also staying within recommended towing loads.
It seems owners have to accept the motor industry is heading down the pathway of replace rather than repair, regardless of the cost these days.
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