Transmission makers are always throwing the repair industry curveballs. The challenges seem endless. Sometimes manufacturers will let us know of changes they are doing, while other times they let us figure it out as we go. I would like to go over a few examples we’ve encountered that may help you on a simpler installation
A Mazda with the “SKYACTIVE” FW6A-EL transmission uses pressure switches to monitor the clutch application. When engagement pressure is supplied to the applicable clutch and brake, the oil pressure switch contact point closes. The TCM detects that clutch engagement pressure is supplied to the clutch/brake by opening/closing the oil pressure switch contact point. There have
Complaint: A Ford with a 4F27E transmission was just overhauled and now has a complaint of a shift from second gear to neutral. Cause: This transmission needed to have the rear planetary that splines to the direct clutch hub, refer to figure 2, replaced, a planetary was taken from parts stock and installed. The planetary
You can now purchase the hardened splines to repair your TF81 differential.
An exploration of the one way clutch in Mazda SkyActiv FW6AEL.
You may remember back in the early days of the 41TE transmission (A604), the sun gear was known to shear off the shell. The result would be no reverse; it would take off in 1st gear but when it shifted into 2nd it would neutralize. With 2nd gear being failsafe, it would default to a neutral gear. The vehicle would then have no movement both forward and reverse. Once the ignition was cycled off to on, you could once again take off in 1st and shift into a no-move condition.
The phrase, “It’s the little things,” is often times pared with “that count” or “will get you.” Both are true when it comes to a loss of reverse after rebuilding a 4F27E. It is easy to overlook the little things that count and it will be the little thing that gets you.
A 2006 Mazda 3 with a 2.3L engine using a front-wheel-drive five-speed automatic transmission (FS5A-EL known as the FNR5 in Ford) comes into Bebes Transmitech shop in Puerto Rico. The A/T warning lamp is illuminated so codes were immediately checked. Only P0791 was stored in memory. It was logged and cleared before going on a road test where the code set immediately after take off.
Have you ever installed a TF80, TF81 or TF60 after overhaul and it has had harsh shifts or engagements, or maybe there has been a flare/bump upshift or harsh coast-down clunks? Most times, clearing the shift adapts and driving the vehicle to relearn the shifts will correct these annoying problems. After a good, long test drive to relearn the shift adapts, sometimes a shifting or engagement problem remains. Assuming that there is not excessive wear in the valve body and the linear solenoids are good, the clutch-control valves on the valve body can be adjusted to correct these problems.
On occasions technicians may find themselves fighting a loss of line-pressure rise with a GF4A-EL transaxle. The transmission has been unplugged and line pressure still does not rise, verifying that there is, in fact, an internal transmission concern. The pressure-control solenoid has been replaced, the pump and spool valve have been inspected and determined to be in proper working order, and the pan has not been pushed up into the newly installed filter.