Mastering the Mysteries of Synchronizers
In a transmission we have a sequence of events that must take place in a precisely timed manner to get a smooth, effortless, clash-free shift. Let’s follow these events to understand the theory of operation and with that knowledge find the solutions that will fix and prevent further shift problems.
4T65-E’s and the Mysterious Code P0730
A 2001 Buick Century Custom came to a transmission shop with a complaint of jerky shifts. A road test of the vehicle showed that all shifts were harsh, and a scan check registered the generic gear-ratio-error code P0730. Since code P0730 does not illuminate the malfunction-indicator light, the harsh shift was the customer’s only clue that anything was wrong.
June 2004 Issue
Issue Summary:
Some 1997-2002 vehicles equipped with the 4T40-E or 4T45-E transaxle may exhibit harsh engagements and/or harsh upshifts and may have trouble codes PO112, PO113, P1111 and/or P1112.
Since the introduction of the THM 4T40-E transaxle in 1995, there have been three different design levels of the accumulator springs and their locations.
Some 2003-model THM 4T65-E transaxles come equipped with a newly designed input and third pawl-clutch assembly instead of the previous-design input and third sprag clutch.
Beginning in June 2002 Hydra-matic changed the design of the oil-pump assembly on 2002 and 2003 models of the 4T65-E transaxle.
I See It, But I Don’t See It!
Incorrectly installed 4T65-E internal mode switch causes shift problems
I got a call from a technician who was working on a 4T65-E. It seems that after the freshly rebuilt transmission was re-installed, the car would not start in park or neutral and the transmission would make a wrong-gear start and shift only once. I came to find out that this was not an original problem, which means it was created during the repair process.
Rich or Poor, It’s Nice to Have Money!
When you have money, you’re in control. When you don’t, other people are in control of you. You work because you owe. That is never a comfortable position to be in. Cash is king. When you have it and others don’t, you can compete on a higher plane.
A New Way of Looking at Things
If a 1998 or newer Kia enters your shop with code P1624, MIL request signal from TCM to ECM, and/or P1121, TPS signal malfunction from ECM to TCM, here’s a new approach to diagnosing and solving the code.
I Don’t Like the Cold
The past winter months brought to surface a condition of no upshift from first gear when cold with the SAAB/Volvo 50-42LE transmission. When it warms up, all shift sequences are restored. The time in which this occurs varies.
Why Don’t They Make Any Money?
I spent the past two evenings presenting an advanced sales seminar and one on figuring the cost of doing business to a group of owners and managers of transmission and general-repair shops. One shop owner showed up with his entire crew – a service writer and three technicians. As I was speaking with him after class, he told me that his main reason for bringing them all was to show them where the money is supposed to be made, how it gets paid out and what’s supposed to be left over as profit. He also wanted them all to realize that everyone in the shop eventually comes into contact with customers in one way or another, meaning that they all play a role, no matter how small, in making the sale.
Miracles Do Happen
A 1995 Jeep Grand Cherokee was brought to a Cottman Transmission shop in Jennings, Mo. The customer‘s complaints were typical for this model transmission and correct for the mileage of the vehicle. A complete transmission and converter rebuild were sold and, because of the chronic cooler-line problems, a cooler-line update was sold for added security.
May 2004 Issue
Beginning at the start of production for some 1999 models, BMW introduced a new five-speed automatic transmission (see Figure 1) that is designed and manufactured by General Motors Powertrain division in Strasbourg, France. This new transmission is designated the A5S 360R in BMW 3-and 5-series applications and the 5L40-E in Cadillac CTS applications.
The 5L40-E transmission is a completely new-design rear-wheel-drive unit and was designed to be a four- or five-speed. The same case and components are used for both applications with the exception of the 2nd clutch and the 2nd sprag clutch, and the use of a smaller Ravigneaux planetary carrier assembly in the four-speed version.
Six-Speed Solutions
The T56 now is found in Camaros, Firebirds, Dodge Vipers, C5 Corvettes, Aston Martins, the Australian Holden, Mustang Cobra R’s, the new Pontiac GTO and the just-released Cadillac CTS-V. Tremec also developed an aftermarket T56 unit that replaces the T5 units used in earlier Mustangs, Camaros and Firebirds. This unit is a direct bolt-in, which will require some modification to the cross member, driveshaft and, on Mustangs, the exhaust system.
When Is a Stick Not a Stick?
Which brings us to the meat of this article, which is BorgWarner’s DualTronic™ six-speed transmission, otherwise known as a DSG (direct shifting gearbox) or AMT (automated manual transmission), which was adopted by Volkswagen and Audi when the VW Golf R32 and the Audi TT 3.2 made their debuts.
