Advanced Clutch Diagnostics
Clutch replacement is a common shop repair that is a profitable and relatively simple job if you follow proper inspection and installation procedures. About 50% of all manual-transmission failures or wear-related problems begin with a worn or damaged clutch.
August 2004 Issue
Allison World Transmissions are fully computer-controlled transmissions that come in three truck models and four bus models. The model designations are AD, MD and HD, and each is rated for different gross vehicle weights (GVW).
Morning Sickness – Well, Sort Of
At ATSG we have received several calls on the 5R55N/W/S transmission in the new Lincoln LS, Jaguar, Ford Explorer or Mountaineer concerning a complaint of delayed or no engagement. The condition occurs most often during first morning startup, under extreme cold-temperature conditions, and the transmission may engage if the throttle is snapped wide open.
What Is a Rebuilt Transmission?
A silly question to be asking people who have been in the transmission rebuilding business for so long, isn’t it? It does, however, seem to get a lot of different replies. If you ask 100 rebuilders you might get 10 different interpretations. That could be why some states have adopted regulations for the minimum standards to which a transmission can be rebuilt and still be called a rebuilt, reconditioned, overhauled or remanufactured transmission. The words all mean the same thing in these states because the lawmakers didn’t want shops to get around the regulation by calling the rebuilt something else.
It’s an Inside Job
The 2003-and-up Audi A4 and the 2002-and-up A6 with a 1.8- or 3.0-liter engine use a continuously variable automatic transmission known as the Multitronic® 01J (see Figure 1) and also referred to as the VL300. The core of this article is not that this transmission is a CVT. The focus is on what’s inside the transmission other than the drive- and driven-pulley set.
July 2004 Issue
Issue Summary:
Before or after overhaul, vehicles equipped with the 4L30-E transmission may exhibit a binding sensation on take-off in Drive or on the 2-3 upshift.
Hyundai vehicles equipped with the F4A42/51 transaxle may come in with complaints of erratic and/or harsh shifting, third-gear failsafe and one or more codes for open or shorted solenoid circuits.
After overhaul, Mitsubishi vehicles equipped with F4A40 or F4A50 series transaxles may exhibit shuddering engagements or harsh upshifts.
Before or after overhaul, Mitsubishi vehicles equipped with F4A40 or F4A50 series transaxles may exhibit a flared or harsh upshift into third gear.
Broken Brakes: Answers to Some Parking-Brake Problems
Bolt-on parking-brake assembly on some ZF manual transmissions requires careful handling.
Ford light-duty trucks have been equipped with ZF five- and six-speed manual transmissions since 1987. The ZF S542, S547, S547M and S650 have been used behind gas and diesel engines and are manufactured in two- and four-wheel-drive versions.
Orbiting the World of Saturn’s CVT
The VT20/25-E CVT transaxle, otherwise known simply as VTi, is a transmission built in the Fiat GM Powertrain Plant in Hungary and is on the road in the United States in Saturn’s Vue SUV and in the Ion Quad Coupe.
No Lockup for No Reason?
Here’s a real-life example of a problem that came into our shop. A 1998 Chevrolet pickup with a 4L60-E was brought in with complaints of no reverse, no 2nd and no 4th gear. We figured this was a routine job. In fact, it’s usually a “gravy” job. We started the job by scanning for codes and found P1870 and P0300.
‘Sleight of Hand’
Another problem area also can be the throttle-pedal cable. This cable is so long that it eventually stretches (see Figure 1). When you step on the throttle, the TPS responds by lowering the voltage (yes, lower voltage; the TPS ranges from 4.5 to 0.5 volts), at which time the injector-pump lever has not been moved.
A Penalty for Excellence!
The outcome of this trial could influence how states that have regulations on auto-repair practices might dictate by what means work is priced in the future.
Ford 4F27E Shift Strategy – a Different Way of Doing Things
The 4F27E transmission uses two on/off solenoids and three PWM solenoids to produce each of the shifts and converter-clutch apply, as the chart in Figure 1 shows. The EPC solenoid is used to control line pressure relative to engine torque. So far this sounds easy, but from a strategy standpoint, it progressively moves toward a “different way of doing things” when compared with what we are accustomed to.
