March 2012 Archives - Transmission Digest
Toyota’s U660E Flex Lockup Control

Toyota’s six-speed U660E (Figure 1) uses a converter-clutch strategy called flex lockup control. A partial explanation of this flex control strategy by Toyota follows:

During acceleration, flex lockup-clutch control operates when the transaxle is in second gear or higher and the shift lever is in the D, S6, S5 or S4 range position. During deceleration, it operates when the unit is in fourth gear or higher and the shift lever is in the D, S6, S5 or S4 range position.

A New Look: 2012 Fiat 500

Long time no see! Fiat 500s are making their way across the Atlantic and into U.S. bays

“Fix It Again Tony” was the joke from the last adventure Fiat had in America. Well, thanks to Chrysler Motor Co. looking to the taxpayers for money, a deal was struck with Fiat to take it over and pay us all back. So far, so good. One benefit for Fiat is an instant dealer network that is now selling a small retro version of an Italian mini-car sold back in the ’50s. Is it any good? Or, more important, can the typical technician in the U.S. service this little vehicle, or should they stay away?

Only One Way – the Right Way

Those of you who read my articles know that from time to time I may bore you with gear-train operation. It’s a part of the transmission’s operation that has always fascinated me. Understanding it goes a long way toward diagnosing various complaints, especially those involving noise.

In this instance I’m going to talk about a one-way-clutch device in a 62TE transmission (figures 1 & 2). But I first need to go through my boring explanation of the “foot bone being connected to the ankle bone” type details of the underdrive centerline shaft known as the underdrive compounder assembly (Figure 3).

March 2012 Issue

In This Issue
Ford 5R110W: New-design pan and sump filter
Ford 5R55W/S 4X4: Metallic clank on engagements
Ford 4R75E: Transmission overheats
Ford 4R75E: Erratic operation with various codes
6L40/50/80/90, GM6, GA6L45R: Solenoid performance codes


No, not wheel alignment – people alignment; aligning yourself with the right people for the situation you happen to find yourself in at any given time.

All the books we’ve read and audio programs we’ve listened to about goal setting and achievement tell us that after we decide on what we want and set a goal we have to make and stick to a plan. Part of that plan has to be identifying and aligning ourselves with people in the right places who can help us get what we need.

Humming Along with the BorgWarner 4493/4494 Transfer Case

GM had great sales for a time with the Hummer brand. The economy has foreclosed on that segment of the market, and GM has sold the brand to a Chinese company. However, there are lots of Hummer H3s around and no dealer body to repair them, which sounds like opportunity for the transmission shop.

The Hummer H3 was available with either an automatic or manual transmission and used a 4493/4494 transfer case manufactured by BorgWarner. The 4493 and 4494 are operationally the same transfer case, a three-position, electrically shifted unit. The 4493 has a 2.64 low-gear ratio and the 4494 has a 4.1 low-gear ratio, which makes it a good rock crawler for the off-road guys. This obviously means that the internal gear trains will be different.

Quit Dimpling Those Converters

This all started with my looking at multiple converter failures caused by the converter bolts damaging the backs on Toyota A245E/A246E transmissions used with the 1.8-liter engine. We also see this in other Toyota applications, maybe more so than with other vehicle manufacturers.

My intentions were to order some factory bolts to get the proper dimensions and possibly send these reman units out with new bolts, either OE or an economical replacement bolt. I was hoping this would eliminate any confusion for the R&R technician as to which bolts were the proper ones to go into the converter, hence eliminating unwanted warranty repairs.

Clearing up Some Toyota Solenoid Confusion

Different terminology for the same part has been an ongoing problem in the transmission industry ever since I can remember. When I was learning to rebuild transmissions, Chrysler Torqueflite and Ford C-4 transmissions were always in the shop. These two transmissions had the same power flow, but all the internal components had different names.