well it's been a while since anything has broken (all but a rear brake adjuster cable causing the rear to lock up every time I touched the brakes), so I'm looking at the 91 again, the one that slipped, lost drive, regained drive, lost OD regained OD for a while, lost drive, regained drive and no longer has OD, a year ago the box was rebuilt to cure an oil leak as the seal let go in a big way, also oil pump replaced. The van is being used in 3 gear form now and is without trouble however I'd like to get OD working again, first up would be the unit held in by a circlip, would that be the first thing to play with, I have a known good gearbox on the garage floor and although I don't want to pull it apart, if it proves whats wrong I don't mind doing it and then if it works buy the new component for the van and put spare box back together as it was. If I do this and it doesn't work would it be fair to go pulling the sump and going for the servo??
if I'm on the right track, which one is the OD module one nearest the engine or the one behind it?
Thanks in advance

 

First, are you getting a CE light, or any code for that matter?

 

opps, sorry forgot, nothing shows up whatsoever, my wife just drives and drives it, no warning lights no jerky gear change, no slipping, loads of power throught the first 3 gears (up to 130 km/h) sometimes I have to manually slip to 3 just to see if the OD is still not working.
Just thought, if I pull codes it will show something wrong as this is the one I have put the switch to select 50-50 lock on, this is the solenoid thought rather then the gearbox as with a manual selaction it works great.

 

Hi X.L.R.8.

If you don't have OD, I would suspect the 3-4 shift solenoid is busted, or there is something wrong with the valve body. The 3-4 shift solenoid is the one toward the middle of the valve body, not the one right at the edge (which is the Torque Coverter Clutch Solenoid).

For your specific question, the OD assembly is the one closest to the engine. You should see it immediately once you removed the bellhousing. I don't think there is any retaining ring. Just make sure you label all the thrust washers and put them back in their proper place after you are done.

 

many tranny codes will not set CEL
must run full KOEO and KOER tests for all codes

check and clean the 4 wire electrical connector on the tranny....one circuit controls 3/4 shift from ECU and other is torque converter lockup....easily damaged and exposed to corrosion

from Ford Service cd A4LD

PINPOINT TEST A: DIAGNOSTIC TROUBLE CODES: 86/566 SHIFT SOLENOID 3-4/4-3 CIRCUIT FAILURE


Diagnostic Trouble Codes 86/566: Shift Solenoid 3-4/4-3 Circuit Failure

Pinpoint Test A is intended to diagnose the shift solenoid electrical system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

l Engine

-- Performance, Cooling, Brakes

l Electrical

-- Battery, Input Sensors, Wiring Harnesses

l Transmission

-- Internal Transmission Components, Linkages, Cooling

This Pinpoint Test is intended to diagnose the following components:

l Transmission Wiring Harness, 3/4 Shift Solenoid, Vehicle Power (VPWR)

l Powertrain Control Module.






² A1: A4LD ELECTRONIC DIAGNOSTICS
² A2: CHECK ELECTRICAL SIGNAL OPERATION
² A3: CHECK CONTINUITY OF SOLENOID SIGNAL AND VPWR HARNESS CIRCUITS
² A4: CHECK SOLENOID/HARNESS FOR SHORTS TO POWER AND GROUND
² A5: SOLENOID FUNCTIONAL TEST
² A6: TRANSMISSION DRIVE TEST
² A7: CHECK RESISTANCE OF SOLENOID/HARNESS
² A8: CHECK SOLENOID/HARNESS FOR SHORT TO GROUND
² A9: A4LD INTERNAL ELECTRONIC DIAGNOSTICS
² A10: CHECK INTERNAL A4LD HARNESS CONTINUITY
² A11: CHECK INTERNAL HARNESS FOR SHORTS TO GROUND
² A12: CHECK SOLENOID RESISTANCE AT SOLENOID
² A13: CHECK SOLENOID FOR SHORT TO GROUND