Gear Shifting
#2
RF Veteran
iTrader: (1)
1990 4.0l will have an A4LD 4-speed with electronic controlled Torque converter and 3rd/4th shift.
There will be 3 wires connected to a D-shaped connector on the side of the transmission.
1 wire will have 12volts with Key On
Other 2 go to the computer, one locks torque converter, the other shifts the OverDrive(OD), the 3rd/4th shift.
But that's all it controls
Transmission in Drive should shift on its own from 1st to 2nd and 2nd to 3rd, if that doesn't happen then you have internal problems.
Automatics work on pressure, and higher RPM = higher pressure, when pressure gets high in one gear valves open and it shifts to the next gear, no shift means either valves are stuck or gaskets are leaking(no pressure build up).
But trans needs to come out in any case.
If the replacement trans was a rebuilt then it will be under warranty, if it was a used transmission you bought someone else's problem.
Good read here on A4LD:
There will be 3 wires connected to a D-shaped connector on the side of the transmission.
1 wire will have 12volts with Key On
Other 2 go to the computer, one locks torque converter, the other shifts the OverDrive(OD), the 3rd/4th shift.
But that's all it controls
Transmission in Drive should shift on its own from 1st to 2nd and 2nd to 3rd, if that doesn't happen then you have internal problems.
Automatics work on pressure, and higher RPM = higher pressure, when pressure gets high in one gear valves open and it shifts to the next gear, no shift means either valves are stuck or gaskets are leaking(no pressure build up).
But trans needs to come out in any case.
If the replacement trans was a rebuilt then it will be under warranty, if it was a used transmission you bought someone else's problem.
Good read here on A4LD:
When having an A4LD rebuilt, there are a couple of things that you need to make sure of. First and foremost, do not let a shop do a soft parts fix only (clutches, servos, and bands). This will almost ensure that you will have another repair needed right after the 1-year warranty is out. Other things you want to have replaced are: forward one-way clutch (always), overdrive drum (stamped tin, replace if out of round or heat damaged), pump (Ford only, rebuilds are prone to failure), and the converter (get the better converter with the improved lock-up clutch and brazed fins).
#4
RF Veteran
iTrader: (1)
There is a "vent" on the top side toward the rear, it should have a metal tube running across the top and then loop back to bell housing.
Picture here of Vent, Green circle: Ford Transit Forum ? View topic - A4LDe Autobox
On the Passenger side there is a "Vacuum" hose hook up, it should have a rubber vacuum hose running up to engine and then hooked to intake manifold
In above picture, just below the end of the green arrow you see a gold part, that's the vacuum modulator
Neither of these would cause the "no shift" problem
Picture here of Vent, Green circle: Ford Transit Forum ? View topic - A4LDe Autobox
On the Passenger side there is a "Vacuum" hose hook up, it should have a rubber vacuum hose running up to engine and then hooked to intake manifold
In above picture, just below the end of the green arrow you see a gold part, that's the vacuum modulator
Neither of these would cause the "no shift" problem
#7
RF Veteran
iTrader: (1)
#10
RF Veteran
iTrader: (1)
Yes and no.
First, on an automatic swapping bell housing is a complete rebulid, and it must be from same model trans, on most.
Second, '95 and up transmissions will need a computer to operate that model.
'90 A4LD just had 2 controls and OBD I(EEC-IV) computer, '98 and up needs a computer with more controls, it is also a OBD II(EEC-V) computer.
So yes, if you get a OBD II computer for '98 and up transmission(also must be for your engine size), and add some sensors OBD II requires that OBD I didn't, extra O2, Crank position, cam position, probably others I can't think of.
And no, if the above seems like a pain in the a$$, it does to me.
First, on an automatic swapping bell housing is a complete rebulid, and it must be from same model trans, on most.
Second, '95 and up transmissions will need a computer to operate that model.
'90 A4LD just had 2 controls and OBD I(EEC-IV) computer, '98 and up needs a computer with more controls, it is also a OBD II(EEC-V) computer.
So yes, if you get a OBD II computer for '98 and up transmission(also must be for your engine size), and add some sensors OBD II requires that OBD I didn't, extra O2, Crank position, cam position, probably others I can't think of.
And no, if the above seems like a pain in the a$$, it does to me.
Last edited by RonD; 09-10-2015 at 09:28 PM.
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CapeFear562
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01-28-2009 08:45 AM