Valve Body Archives - Page 6 of 6 - Transmission Digest
Adapting to the AW55-50SN Valve Body

Some things are less intimidating if you’re not the first to do it. That statement applies to both crossing a frozen lake and working on a problematic AW55-50SN. On the lake, heavy snow cover can prevent you from telling whether the ice is sufficient for support, and what you can’t see may end in a sink-or-swim experience. On the 55-50SN valve body, a clean core does not mean the valve body is functioning correctly.

Volkswagen’s Direct-Shift Gearbox Part 5

The DSG valve body is definitely one of the simplest we have seen in transmissions (see figures 1 through 5). It contains only five valve line-ups, two checkballs, three damper assemblies, two pressure senders (pressure sensors/transducers) and 13 filters (see figures 2, 3 and 5).

Toyota Matrix U341F

In rebuilding today’s transmissions one has to be very careful with the small parts that come in these valve bodies, such as checkballs, solenoid filters, springs and relief valves. These small parts might seem insignificant, but they play a vital role in the function of the transmission. Many rebuilders dread rebuilding valve bodies with all these intricate parts that are so easily misplaced or lost. On the 50-42LE found in many Volvo, Daewoo and Saab vehicles, if the valve-body filters are installed incorrectly they can cause problems such as no reverse or lockup issues.

TAAT Reverse Issues

A Saturn with the TAAT comes into your shop with a delay, slip/bang or no reverse at all. What is the first thing you do? Get a valve body. It’s always the valve body. The only thing that goes wrong with a TAAT unit is the valve body. We can do this in an hour or so.

Valve-Body ‘Kibbles & Bits’

In all the years of building transmissions, I think the worst thing that could happen is having the R&R guy, manager or owner come back after a road test and tell you, “It’s not working.” All of a sudden you get this knot-in-your-stomach feeling that makes you wish this were not really happening.

Building a Reaming & Inspection Station

As valve bodies continue to evolve and become more complex, rebuilders are finding it increasingly necessary to have a central location for bench reaming and inspection of valve bodies. Many transmission shops have found – to their surprise – that building an inspection and reaming station can be inexpensive and that a station can be put together from many items already available in the shop.

Getting VTi Leverage

This transaxle has a bi-directional ratio-control motor (RCM) on top of the valve body (see Figure 1). The RCM indexes with a lever attached to the variable-ratio-control valve in the valve body, as Figure 2 shows. The opposite end of this lever sits inside a pocket of a device called the drive-pulley follower, as shown in Figure 3 from the valve-body case side with the valve body removed.

Back to the 40s and 50s

The F4A42 hit the streets in 1997 in the Mitsubishi Mirage. Since then it has grown into a F4A51 and has found its way into larger Mitsubishi models as well as Hyundai vehicles. This month we’re going to explore some valve-body-related issues, look at valves that can be installed incorrectly and provide some explanations about valve function.