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  1. The AKPPro Magazine
  2. Tools

Useful tools for transmission repair

OBD diagnostic and error codes

Each transmission repair starts with the diagnostics. This process includes checking of level and quality of the oil, pressure measurement, stall testing, and computer-aided diagnostics to determine transmission control problems. The electronic control unit ECU (PCM, TCM, ECM) can detect malfunctions by means of reading out and processing the information related to the transmission operation.

Gear Ratios

This ratio tool is broken down into Simpson, Ravenaux, overdrive and undersrive gear sets. The tool allows you to calculate gear ratios on a wide range of transmissions. The basis of the calculator is the three-speed Simpson or Ravinaux gear set. Many late-model transmissions use a combination of these gear sets and the overdrive (or underdrive) set to achieve the various ratios. Once you understand the combinations of gear sets being used you easily calculate all the ratios of the transmission. This tool comes in handy for performance applications where you`re considering a change in gear sets and need to know the ratios for each range.

Pressure Analyzer

The Pressure Analyzer is a tool for calculating pressure regulator output. It allows you to consider different springs and boost valves and then allows you to calculate regulator pressure output through a range of EPC/TV pressure input. It works with valves having only one reaction area and those with two. Begin by entering the reaction diameter(s) of the regulator valve. Next, enter the spring force (at its working height). The working height is the height at which the spring is compressed while the valve is regulating. If you`re unable to measure the valve`s working height use the optional method, though it`s less accurate. Measure line pressure in neutral with ZERO EPC/TV pressure and enter it in the `Pressure Regulator Output" field; The program will calculate the spring weight. Now you can use a scale and caliper to compress the spring to that weight and measure the height. Now enter the remaining valve dimensions in the system (reverse and EPC/TV boost). With this data, the program will calculate regulator pressure at zero EPC/TV pressure all the way through maximum (generally 90psi or so). If the system you`re testing has different boost valves and springs available you can substitute them into the program and calculate regulator pressure output. Once you`ve input all teh data you can use the Pressure Graph to draw the pressure rise through its entire range.

Orifice Calculator

The Orifice calculator allows you to increase or decrease an orifice two ways: By adding or subtracting an orifice dimension or by percent. For example, if you create an orifice in an apply piston, such as a servo, in order to allow cross-leaking oil to escape when the servo isn`t applied you can add that orifice dimension to the feed orifice to make up the difference of the leak you created by adding the orifice in the piston. Or, if you`re experimenting with orifices for performance enhancements you can increase or decrease the original orifice size based on percent. This allows you to use an accurate dimension as you experiment with orifice size for performance.

Standard Gear Ratios

Just fill in the gear tooth counts and the program will calculate the ratios.