December 2011 Archives - Transmission Digest
December 2011 Issue

In This Issue
Nissan RE5F22A: Harsh downshift on throttle-up
Mercedes Benz 722.6: Bogs down in third gear

You Can’t Win Every Argument

I found myself in an argument the other day that I couldn’t win no matter how right I might have been. It was with two golf buddies who know I’m in the auto-repair business and chose to vent their frustration about the cost of car repairs on me.

End-of-the-Year Roundup

All markets historically rise and fall on the basis of demand cycles. The government has interfered with natural cycles continuously and created the situation that we now face. President Clinton revived the Carter years’ “Community Investment Plan,” which was supposed to make home ownership easier for the average citizen. This created a housing boom and a vastly overpriced and overbuilt real-estate market coupled with a complete regulatory failure of the mortgage industry and created the mess we now have to deal with. How hard was it to figure out that if you gave mortgages to people who could not pay their current rent, they eventually would default on their obligations?

Understanding the AW 55-50 Neutral Control

A 2001 Volvo S60 come into or shop with a smoked AW 55-50 transmission that needed to be replaced.

The AW 55-50 transmission has a feature that Volvo calls “Neutral Control.” What is “Neutral Control” and what is its function? To tell you the truth, I wasn’t really sure, but below is what I was able to both find and figure out about it.

Know Your Patient

One would think the easiest part about working on transmissions would be identifying the model you are working on. Nowadays, unfortunately, it’s not always that easy. I was helping via e-mail a technician on a transmission forum who reported having issues reaming a late-model Chrysler FWD valve body. Both he and I were thinking 41TE (A604), but that turned out to be incorrect. What he was working on was actually a 41TES, also known as 41TE VLP.

Serviceability Report: Dodge Dakota – Easy to Fix?

In 2000 the Dakota hit sales of more than 175,000 units, but last year it was a dismal 13,000. The V-6 is the best-selling engine because the RAM1500 gets about the same gas mileage as a Dakota with a V-8. Why write an article about a truck that appears to be dying? If Fiat can save Chrysler it will happen only if they sell vehicles, lots of them, so I think that if this truck stacks up well to the competition we should recommend it to our customers. We will compare the 2004 Dakota V-6 automatic 4WD to the 2011 model.

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.

CVTs – Do I Rebuild Them or not?

The question of whether to rebuild a continuously variable transmission (CVT) has increased dramatically this past year on our technical hotline, and I thought I might risk making a few comments about this subject.

The call comes to our technical hotline a few different ways. The question has been: “Why are people saying you cannot rebuild CVTs?” or, “Is it worth trying to rebuild one of these” or, “What am I getting myself into if I try to rebuild one? What tools do I need?”

My answers to these questions follow.

Front-Seal Blowout after Converter Replacement in 09D/T Transmissions

The Aisin AW TR-60SN/VW 09D/T transmissions are found in the 2002-2010 VW Touareg and the 2003-2010 Porsche Cayenne. There have been reports of the front seal blowing out after the torque converter and related parts have been replaced.

The root cause of the seal blowing out is the buildup of pressure because the drain-back passage that normally vents the area behind the front seal is blocked. This area is normally vented through the stator support/pump cover. The seal-blowout issue occurs when the pump (body and gears) is mated to an incorrect stator support (pump cover) and blocks the drain-back passage. To understand how easy it is to make this mismatch, you need to know the large number of possible combinations. Be aware that the seal-blowout problem is only one of several issues that you can create if you mismatch components.