automatic tranny rebuilt 7 years ago but only 4,000 miles as truck is not daily driver. yesterday tranny bucked & OD light started flashing, wouldn't go into 3rd gear, made it home but seemed to be slipping enough that i don't want to drive it, I've read about solenoid valve & replacing band . Is this something I could attempt myself?

 

Welcome to the forum

I would first get an OBD2 Reader that can scan for Transmission codes, not all can read transmission codes
OBD2 readers work on ANY vehicle, 1996 and newer, so not a Ford thing, a worthwhile tool to have at your disposal

The Flashing OD light means Transmission codes have been set
Look here: https://www.therangerstation.com/tec...II_codes.shtml

Scroll down to P0700 codes, those are "some" of the transmission codes, and they can be very specific or general, but the EXACT code(s) need to be IDed AND the codes the computer did NOT use help as well

Yes, you can change solenoids or the whole Valve Body while transmission is in the vehicle

1998 Ranger 4.0l will have a 5R55E model transmission, 3.0l will have a 4R44E model transmission but they are basically the same so what repair info you see/find applies to BOTH

When was the transmission last serviced?
New fluid and filter

 

The codes are PO733, PO734 & PO735 which are shift code failures, P1832 which is pressure control solenoid & B1352, ignition key in circuit failure

I think the pressure control solenoid is the one to start with

Transmission oil & filter changed recently, fluid is clear, full & not burnt

 

P1832 is a very obscure Ford Code for EPC fault

The other 3 codes do point to a pressure issue, "incorrect ratios" means there was no shifting by clutches and bands, which can be from lower pressure

It would just be a wild guess to change the EPC solenoid with just the above into, changing the whole valve body would be a better approach, i.e. using a shotgun vs a bullet, lol

If you can take the vehicle in and have the line pressure tested, or test it yourself, that may give you more info

 

The scanner I used had a pressure reading, which showed increased pressure when in gear, would having the line pressure tested give more info? I don't think it should be driven so don't have a way to bring it to be tested

 

Have a look here: https://atracom.blob.core.windows.ne.../2003_5_50.pdf

Pressure readings are on page 2

 

Thanks for your input Ron, I adjusted the control solenoid by turning the allen in 3/4 of a turn as described in an ATRA tech seminar article on Ford transmissions, this changed the shifting, smoother in 1-2 , the shift into 3rd or 4th is better, but takes too long & is not correct. I have to drop the pan again to change filter & fluid & think I should replace that solenoid

 

Drove a few more miles & the OD light started flashing

 

The problem with automatics and diagnosing problems is that there are so many interrelated systems

All automatics run on fluid pressure, this pressure is what engages and disengages the clutches, and what engages and disengages the Bands(brakes)
Pressure needs to be above a set point to HOLD clutch's and brakes, and below a set point to not blow out seals and gaskets

The pressure comes from the pump at the front of the transmission, its connected directly to torque convert's outer case and torque converter is connected directly to engine, so pump spins at engine RPMs always
So the pressure created by the pump is directly related to the RPMs of the engine, so pressure goes up and down based on engine RPMs
The pump does have a high pressure valve that will be pushed open if pressure gets too high, just like oil pump's high pressure valve

The pressure goes to the Valve body, in pre-solenoid days as the pressure rose higher with engine RPMs the valve body "changed gears" to lower the pressure/RPMs using springs and ball valves, this is the "automatic" part of an automatic transmission, and this works OK but not great, especially if you want OverDrive
When solenoids were added it got much easier to select the correct "gear" for speed and RPMs, PLUS load on engine, i.e. pulling a trailer or going uphill

The EPC(electronic pressure control) solenoid was used to try and keep the pressure in a narrower range to reduce seal or gasket issues, also slipping by clutches and brakes

When there is a problem with an automatic 90% of the time it is a pressure issue, but there are MANY places and reasons for pressure loss, seal, gasket, solenoid, clutches, bands, filter, fluid level, even the pump

So there will be no "this is the problem" diagnostic on pretty much any automatic, not a Ford thing, ANY automatic, lol

The Valve Body pretty much covers most pressure losses "normally", but not ALL reasons for pressure loss

Other 10% is mechanical failure in the rotating part of transmission, that's usually easy to detect on a fluid change and seeing metal bits at the bottom of the pan