Adaptation and Shift Learning
Adaptation: One dictionary defines it as “the act of adapting or fitting one thing to another.” That very well describes what we have to do sometimes when we repair today’s modern transmissions. We have to adapt them or “fit them” to their new environment.
I was doing some testing for the research-and-development department of Valve Body Pro that required me to install different 09G valve bodies in a 2005 VW Jetta. Each valve body had different criteria to be tested, so I expected the transmission to engage and shift differently every time it had a different valve body.
A Disappointing Reality
One recent week, Luis was having a problem with an 01M in a 2002 VW Jetta (see Figure 1). It had a slight bind-up on the 3-4 shift. It didn’t make a harsh shift; it was more like a dragging shift that lasted for about 1 second and then suddenly released when it finally went to fourth. Typically, what we see on the tech lines is more of a 3-4 shift flare rather than a dragging shift. This flared-shift complaint is usually due to either an incorrectly assembled K1 or B2 clutch pack or a leak in the K1 pre-fill pressure circuit causing the clutch to release too soon. However, a dragging shift also could be due to an incorrectly assembled K1 or B2 clutch, or a valve-body problem.
