1. Yes ive searched as well as i can
2. yes ive tried to diagnose the issue myself logically

Thank you for your time! Here we go:

Specs:
1998 Land Rover Discovery
80k miles

Issue:
I will describe the full scenario. Suppose you are on a strip of road and you are sitting wiht the gear selector in park, engine running. You then move the gear selector to Drive and release the brake and apply the accellerator. NO Movement. HOWEVER, if you move the gear selector to 1 and accellerate, the car moves. If you "manually" shift from 1, then 2, then 3, then Drive, (and back down again to restart after stopping) the car will drive and operate normally. Reverse also works normally. Fluid level is normal and smells/feels/looks uncontaminated and good. No check engine lights.

Thank you VERY much in advance for any insight!

 

You can try downloading the shop manual (rave cd) below in my signature if you'd like.

Page #435(pdf) of the workshop manual , zf trans , faults.

I don't think you'll like it.
I'd make sure all the linkage is good, also.

luck,greg

 

OK, ive done some work with the shop manual and here is my result.

FAULT- NO 2 FREEWHEEL

I have done full text searches and see something in the diagram. Can anyone shed more light on this subject or experiences?

 

That might be a tough one, as I rarely see posts re:zf trans other than oil change.

I think some BMW's use it FWIW.

Somebody may chime in.

How's the fluid?

Something may be sticking if it was ignored for long enough, Mine seemed to come alive when I changed fluid in it.

luck,greg

 

I would almost beleive its a bad solenoid in the valve body of the trans. Im not that familiar with the ZF trans to help out to much. I would pull the pan and see if one of the solenoids are stuck/bad.

 

I may be wrong about this, but given the OBDII nature of the vehicle, wouldnt I get a "Check Engine" light with a misfunctioning solenoid valve (or valve body malfunction in general).

Here is something else, and once again, i admit my newbie status. Hear me out:


The "4 wheel drive selector" (the stubby guy close to the HVAC controls) only moves in a Left and Right fashion. There is no ability, whether slowly rolling in NEUTRAL or stationary in NEUTRAL to move the 4WD selector anyway other than left and right. Is this normal? I DO indeed get an orange "4 wheel indicator" on the gauge cluster when i move it to the LEFT

any more insight?

 

Mopar - your linkage is frozen up. On your D1 it should move forward to neutral then low range as well as to the left to lock the CDL. The light comes on to let you know the CDL is locked.

 

I have the same issue with my 97 disco. What have you found out. Im getting ready to add "Lubeguard" elixer any info would be helpful. I strongly agree with your comment about no check engine light equates to no bad solenoids.

 

Haha,
I can NAIL this one.
ZF 4HP22.
Bad Sprag clutch.

Here is the proof:

I have a 4sp ZF, when I select "D" the vehicle won't move, when I select "1" the vehicle moves off. I can then select "D" and continue to drive normally. If I stop I have to start in first again. Why?
A sprag clutch has "inverted" and will need replacing. No further damage will occur if you continue to drive but you will need to select "1" every time to start moving. A rebuild is required to correct this.


From this site:


Ashcroft Transmissions - 4HP22 FAQ's


Slam! Dunk! Done.