overdrive problem

[rusty260411]

Have to manually shift my 99 ford ranger with the overdrive on to get it to shift through the gears but it shifts fine with the overdrive off also don't have reverse with it on or off

 

[jballard81]

From my very meagre knowledge of the A4LD, this could be a number of things:
-vacuum regulator gone bad
-worn out OD solenoid
-need of band adjustments

others with more knowledge than me might be able to clarify.

 

[RonD]

1999 Ranger 2.5l or 3.0l will have the 4R44E automatic
1999 4.0l will have the 5R55E

But in either case no Reverse is usually a Pressure issue
All automatics work based on fluid pressure in the Valve body

Forward requires 80-100psi
Reverse requires 130-150psi
So if you are losing pressure in the valve body then Reverse is the first to go

"Trans fix" additives do work to increase pressure if gaskets and seals are leaking, but leaks just get worse over time


The pump provides the pressure and it spins at engine RPMs
So if REVing the engine caused Reverse to slam into gear, in the past, its a pressure issue
The fluid from the pump flows to the valve body where it is routed to the clutches and bands that select the ratio(gear) required
R or D(2,1) are mechanical "valves" no solenoids involved, the solenoids are only used for shifting into 2, 3, 4, 5 so forward ratios only

But there is an EPC(electronic pressure control) solenoid which could of course effect internal pressure, but I don't think its capable of effecting low side of pressure, just the high side

There are two external pressure ports on any automatic for testing internal pressure, to see if pressure is an issue
Need a pressure gauge capable of 400psi to be safe

Article here that has pressure readings expected: https://atracom.blob.core.windows.net/gears/2003/2003-05/2003_5_50.pdf

A trans shop can do these tests of course, but they would only do a full rebuild if there was a problem, because of warranty issues
But could recommend that YOU replace the valve body to "maybe" get a few more years of service
If you are at or near 200k miles on this trans then probably best to get it rebuilt
Clutches and bands wear out at 200-250k, some can get up to 300k but that's high side rarity, lol