AW4 NO REVERSE OR NUETRAL

[TALLRAM]

Newbe to this forum - 3rd XJ. My current 1993 4.0 AW4/NP231 loads up the engine in park - will not rev over 2000rpm, has no reverse though you can tell it is loading up, has no neutral and will drive forward. All forward gears and shifting are fine including 1st-(2) which is shared with reverse. No bucking slipping all good in forward high reving tire fry ing. Blockage in the valve body? I have changed the fluid & filter (Dex 3) as per dip stick & drain plug. Since the motor was loading up while idling I pulled the fuse on the tcc lock up - no change. I probably have more than one problem and am curious if a mechanical failure in the torque convertor would cause all this. The TPS and NSS are good, I have yet to ohm the Solinoids but have seen nothing about there function that would not allow reverse. HELP

[MoparManiac]

So you pulled the fuse in the PDC for the TCU?

If you did, then have you adjusted the shift linkage?

[TALLRAM]

I pulled the 10amp auto trans fuse from the box on the passenger fire wall. The first thing I did was put it up on blocks and eliminate the linkage question by pulling the cable and went thru the selector manually with while running with someone braking for me. When in reverse the trans output shaft would not turn. It is possible I have not taken the power from the locking torque convertor by removing the fuse. How do I open that circuit? Would the torque convertor being locked up all the time stop it from reversing?

[TALLRAM]

Will the throttle position sensor cable being out of adjustment affect the line pressure enough to keep me from having reverse? If I do not have neutral doesnt that point back to the valve body? Would a blockage in the valve body cause a loaded condition while idling in park? If the torque convertor has a natural stall speed and the engine is idling normally then why would the transmission cause the motor to load up in park unless the torque convertor is faulty?

Any pointers will be appreciated. I have searched the forum (OEM TECH) and found a multitude of AW4 problems but not this one.

[hidesintrees]

check out your nss (neutral safety switch) on the rear driver side of your tranny. clean it put diaelectric grease in it and see if that does something? or test it?

[yozsef]

Originally Posted by hidesintrees

check out your nss (neutral safety switch) on the rear driver side of your tranny. clean it put diaelectric grease in it and see if that does something? or test it?

thats not gonna affect anything.

NO REVERSE (D RANGES
OK)
1. Gearshift Linkage/Cable
Mis-adjusted/Damaged.
1. Repair or replace linkage parts as
needed.
2. Park Sprag Sticking. 2. Replace overdrive annulus gear.
3. Rear Band Mis-adjusted/Worn. 3. Adjust band; replace.
4. Valve Body Malfunction. 4. Remove and service valve body. Replace
valve body if any valves or valve bores are
worn or damaged.
5. Rear Servo Malfunction. 5. Remove and disassemble transmission.
Replace worn/damaged servo parts as
necessary.
6. Direct Clutch in Overdrive Worn. 6. Disassemble overdrive. Replace worn or
damaged parts.
7. Front Clutch Burnt. 7. Remove and disassemble transmission.
Replace worn, damaged clutch parts as
required.

CREEPS IN NEUTRAL
1. Gearshift Linkage Mis-adjusted. 1. Adjust linkage.
2. Rear Clutch Dragging/Warped. 2. Disassemble and repair.
3. Valve Body Malfunction. 3. Perform hydraulic pressure test to
determine cause and repair as required.

[TALLRAM]

I appreciate the help, since I have addressed the external I quess I will pull the valve body and inspect for trash/blockage or wear. I am still suspect of the torque convertor but all the failures I have seen on them lean to slipping not siezing. The AW4 as I understand it has no bands to adjust unlike the 3-spd. I am hoping for a simple cure meaning low dollar and would imagine someone has been thru this before. Thanks

[Blaine B.]

A simple and cheap cure would be a swap in of another AW4

[TALLRAM]

NOT what I consider simple or cheap.

[mahanja]

The swap isn't too bad. Cheap is relative. Check around for a good salvage.

[poorboy_616]

According to the paper work I recieved when I bought my 87 XJ, the PO bought a used trans from a wrecking yard for $150 US.

They are cheap to find, but you have look hard and in the right places...

[Shorty]

Originally Posted by TALLRAM

I am still suspect of the torque convertor but all the failures I have seen on them lean to slipping not siezing.

seized or not, the TC turns the same direction in all gears, so I'd have difficulty seeing it stop your reverse gear but function "tire fryingly" good in forward.

I'm leaning toward valve body plugged up/ gummed up

[Ecomike]

Sounds like a linkage problem to me!!!!! Especially with the forward motion in neutral.

[broqenjeep]

CLEAN OUT THE NEUTRAL SAFETY SWITCH

[Shorty]

Originally Posted by broqenjeep

CLEAN OUT THE NEUTRAL SAFETY SWITCH

a good idea...... but it doesn't have ANYTHING to do with his problem.