September 2015 Archives - Transmission Digest
There’s No Excuse

Great people throughout history have chalked up numerous failures before succeeding at whatever their chosen profession or goal. Is it OK to fail? Sure it is, and sometimes often and quite miserably, before finally reaching your ultimate triumphs. Business owners don’t always make it on the first try or the second or third for that matter. Inventors often try and fail hundreds of times before finding a solution. Did you know that the famous artist Van Gogh only sold one painting in his lifetime, all the rest sold after he died, but that never stopped him from painting? Henry Ford went bankrupt five times. Albert Einstein was expelled from school for being a terrible student. Winston Churchill lost every election in which he ran until he became prime minister at age 62.

ZF9HP48 FWD Nine Speed, Part 2

ZFhas outpaced other transmission manufacturers with the nine-speed ZF9HP48 (Chrysler 948TE) FWD. The unit is extremely compact, considering what it does. Unlike the 8HP family, the 9HP is not a mechatronic design. The 9HP uses a torque converter; however, a hybrid version, the 9P48H, will utilize an electric motor instead. The unit, which weighs in at nearly 200 lbs., can be equipped with a mechanical or electronic pack arrangement.

September 2015 Issue

In This Issue
6R140 pump seal installation
Ford Focus takeoff shudder
5R110W low/reverse clutch repair

Diagnosing Solenoid Performance Faults in A761, AB60 & A960 6-Speed Units

The Toyota/Lexus A761, AB60 and A960 6-speed transmissions have been showing up in shops more frequently over the last couple of years. Warranties are expiring and people seem to be hanging on to their vehicles longer these days. Even so, there are a number of different issues with these transmissions, including torque-converter clutch failure that is especially chronic with AB60 Tundra applications. Common to all these units is a problem that sticks out a bit more than the others, though: on-off solenoid mechanical fault codes. You’ll see these as P0751 S1 solenoid performance, P0756 S2 solenoid performance, P0761 S3 solenoid performance and P0766 S4 solenoid performance codes.

Evolution of the T56

BorgWarner designed the T-5 5-speed transmission that became one of the largest by volume of production. Using a very simple single-rail shift mechanism, the T5 was lightweight, came with a 5th-gear overdrive to add to fuel economy, and had a torque rating useable in engines of the period. The first T5 models used brass synchronizer rings and straight roller bearings to support the countershaft. BorgWarner refined the design and created “The World Class T5,” which used synchro rings lined with the same kind of paper material used in automatic transmissions, and went to tapered roller bearings for the gear train. The weak point of the T5 was its small size, which was easy to package in the diverse models of cars that used it, but with such a small centerline between the input and the countershaft, torque was limited to a high of 330 lb.-ft.