Kleetus said:
Yep... I think it picks a different set for the towhaul mode on braking if memory serves me correct.
I would concur on the braking,
the down shift to 1 and 2(or what ever is pretty agressive, its very low and you slow down NOW,
i remember reading something about the 1st unlock and 1st locked(tqconv) or 2nd locked and unlocked, and it took to much time to shift, unlock lock then shift
that was a while ago,
i knew i had it somewheres
TorqShift Transmission:
The 5R110W, or TorqShift, automatic transmission is a redesign of the E40D/4R100. Basically, the gear ratio for first gear was lowered from 2.71 : 1 to 3.09 : 1. To get second gear the overdrive clutch is engaged to give a ratio of 2.2 : 1. Third gear is now the same ratio as the old second gear, 1.54 : 1. The TorqShift is advertised as being a 5 speed automatic, when actually it has six forward speeds. On cold engine operation (below 0 degrees) the overdrive clutch is engaged in third gear for a ratio of 1.09 : 1. The transmission will shift directly to sixth from fourth and fifth is skipped. On a warm engine the shift pattern would be 1st, 2nd, 3rd, 5th (direct drive), 6th.
Shift performance has been improved through completely redesigning the control valve bodies. The E4OD/4R100 used an electronic pressure control solenoid to adjust apply pressures to the clutches and band depending on load and throttle position. This would give you soft, slipping shifts on light acceleration and harsh shifts on hard acceleration. There was no feedback to the computer for EPC--it was also assumed that the EPC was operating as commanded.
There were two shift solenoids that would divert fluid flow to various shuttle valves to engage the clutches and band for each gear. There were also solenoids to control torque converter clutch and coast clutch operation. The problem with this design was having to time the disengagement and application of each apply component so as to not have too long of a lag between gears, or even worse, two gears applied at one time. There was also limited feedback to the computer as far as whether the components were operating as commanded, other than electrical faults. The computer could see if there was no RPM change at the shift points and set a code, but it could not determine if the problem was hydraulic or mechanical in nature.
On the TorqShift there are pressure control solenoids that directly control each hydraulic apply component with no shuttle valves. There is also pressure sensors to provide feedback so the computer knows whether it needs to increase current to a specifc solenoid to get the necessary hydraulic pressure, making each solenoid its own EPC. Since the computer is directly controlling and monitoring the hydraulic flow and pressure to each component, there are no lags between shifts and each shift is very positive without feeling harsh.
Another new feature on the TorqShift is the Tow/Haul mode. Unlike previous transmission models, this does not deactivate overdrive and immediately turn on the coast clutch. You still have all five active gears. Tow/Haul is a second transmission strategy in the computer. When activated, upshifts will occure at a higher road speed for a given accelerator position for better acceleration. Also, when releasing the accelerator on an upgrade, upshifting is delayed to prevent shift hunting.
The torque converter clutch will lock up at a lower vehicle speed for a given accelerator pedal position to provide improved transmission cooling. It will also stay locked longer on deceleration to provide engine braking. Engine braking is also provided on deceleration through the coast clutch. On the older transmissions EPC would always be minimal with the accelerator in the idle or coast position. This would result in slippage during deceleration on steep down grades, especially with a load. When the Tow/Haul mode is selected on the TorqShift, the computer commands sufficent pressure to the apply components to prevent this slippage.
Finally, to help maintain vehicle speed when desending a grade and help increase brake pad longevity, the transmission will downshift automatically. If the computer senses vehicle speed increase with the accelerator released, it will downshift to the next lowest gear. If vehicle speed continues to increase, the computer will command the transmission to downshift again. The grade braking downshift mode will be deactivated if the Tow/Haul mode is deactivated or the accelerator is depressed.
The TorqShift transmission uses a new fluid--Mercon SP. This is not interchangeable with Mercon (Dextron), Mercon V, or synthetic Mercon. Since there is no torque converter drain, servicing is ment to be done by automatic flush machine. The external filter--mounted on the cooler lines near the radiator--needs to be replaced at the service. Ford has no service interval for the internal pickup filter. I think it is a good idea to replace the internal filter at the service intervals as cheap insurance against a failure. There is a second transmission filter screen that is part of the valve body gasket, but it does not need to be replaced unless the transmission is being repaired. If a flush machine is not available, the trans pan does have a fluid drain. You can either drain and refill the transmision pan, start the engine to circulate the fluid, then drain and refill again. Or, drain and refill the pan, then remove the cooler return line and direct it to a drain pan. Start the engine and as fluid is expelled from the cooler line, add fluid to maintain the level in the pan. It may be more advantagious to have a someone helping you for this method. Replace the external filter after changing the fluid. The external transmission filter is installed on a by-pass, so it only filters 10% of the fluid flow. I would be advantageous to install a secondary filter to capture any contaminates the factory one misses.
Charles David Ledger; dieselmann©2003
inteliidog
