2001 Discovery Automatic Transmission Issue

jastutte

Well-known member
Nov 10, 2009
350
33
This is my son's daily driver. Well, it was until recently.

He called me the other day and said he heard a bang and then the Rover stopped moving. It would rev but wouldn't move.

He was able to get it home by shifting into 1st gear and driving slowly back.

He and I drained the fluid in the transmission, it was old and brownish but not burnt smelling and there were no metal flakes.

We put in fresh fluid following the RAVE manual. Whoever decided to remove the transmission dipstick should be poked in the eye.

The truck is drivable but only if we start in 1st gear and manually shift through the gears.

Does this point to internal damage or shift solenoids? Are there fuses I should be checking?

I know very little about automatic transmissions, so any help is appreciated.
 

p m

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Apr 19, 2004
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If I can hop onto this thread without creating a new one...

4HP22 from an 88 RRC installed in a 95 RRC.

Symptom: starts in 2nd, and downshifts into the 1st upon takeoff. Harsh if gas pedal is punched hard. It does not happen if the gear shifter is in 1 or 2; if the gear shifter is in 1, it'll keep in the first gear, 2 - it'll start in the 1st and upshift to the 2nd normally.

Before the transmission was installed in the truck, the governor was removed and Viton O-rings replaced with new.

Any ideas or suggestions?
 

Flyfish

Well-known member
Oct 29, 2004
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Out of curiosity. Any idea what is broken internally?
A common problem with all ZF 4HP22/24 boxes is the failure of the oneway ‘sprag’ clutch. Once the cams in this one way sprag clutch ‘flip‘ the unit will slip both ways resulting in the vehicle only pulling off with the shifter in position ‘1’ not ‘D’ and driving OK when shifted up to position 2,3 and D until you stop then you need to pull it back to ‘1’ to start off again.
 

special ed

Active member
Apr 11, 2012
31
2
Elsinore
If I can hop onto this thread without creating a new one...

4HP22 from an 88 RRC installed in a 95 RRC.

Symptom: starts in 2nd, and downshifts into the 1st upon takeoff. Harsh if gas pedal is punched hard. It does not happen if the gear shifter is in 1 or 2; if the gear shifter is in 1, it'll keep in the first gear, 2 - it'll start in the 1st and upshift to the 2nd normally.

Before the transmission was installed in the truck, the governor was removed and Viton O-rings replaced with new.

Any ideas or suggestions?
Most of the time, what your experiencing is cracked governor seals. Easy to repair once tcase is pulled. Fluid is bypassing the governor and the valve body thinks the car is still moving so it does not shift back into 1st unless manually selected.
 
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Flyfish

Well-known member
Oct 29, 2004
1,143
103
49
St. Louis
If I can hop onto this thread without creating a new one...

4HP22 from an 88 RRC installed in a 95 RRC.

Symptom: starts in 2nd, and downshifts into the 1st upon takeoff. Harsh if gas pedal is punched hard. It does not happen if the gear shifter is in 1 or 2; if the gear shifter is in 1, it'll keep in the first gear, 2 - it'll start in the 1st and upshift to the 2nd normally.

Before the transmission was installed in the truck, the governor was removed and Viton O-rings replaced with new.

Any ideas or suggestions?
How loose/tight is your kick down cable? Sounds too tight.

And also, when the kickdown cable is attached inside the valve body, the spring cam it attaches to has to be preloaded by 1 turn before connecting the cable. Wasn’t sure if that had been removed or not.
 

p m

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Apr 19, 2004
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Most of the time, what your experiencing is cracked governor seals. Easy to repair once tcase is pulled. Fluid is bypassing the governor and the valve body thinks the car is still moving so it does not shift back into 1st unless manually selected.
It may be... but the governor seals were brand new when the transmission was installed.
I got myself a set of steel seals just in case - Viton ones become hard to find.
How loose/tight is your kick down cable? Sounds too tight.

And also, when the kickdown cable is attached inside the valve body, the spring cam it attaches to has to be preloaded by 1 turn before connecting the cable. Wasn’t sure if that had been removed or not.
I loosened it up quite a bit; can't say if it made things better (it didn't make things worse).

Really not in a mood to pull the transfer case again...
 

Flyfish

Well-known member
Oct 29, 2004
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St. Louis
I loosened it up quite a bit
Hopefully you kept track of how much you loosened it. Maybe do one turn at a time on the adjustment knob for a few turns to see what difference you notice. If nothing or worse, go back to the original setting and do the tests except tightening.
 

p m

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Apr 19, 2004
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Hopefully you kept track of how much you loosened it. Maybe do one turn at a time on the adjustment knob for a few turns to see what difference you notice. If nothing or worse, go back to the original setting and do the tests except tightening.
It's a kickdown cable - no knob on it, just two 13-mm jam nuts.
I found that, the looser is the kickdown cable, the less-frequent and less harsh is that 2->1 downshift at the start.
Maybe indeed I need to pull the pan and filter and check/replace the kickdown cable.
It doesn't mean the O-rings on the governor don't need attention...
 

Flyfish

Well-known member
Oct 29, 2004
1,143
103
49
St. Louis
It's a kickdown cable - no knob on it, just two 13-mm jam nuts.
Lol. Sorry, had two conversations going at the same time, but correct.

Proper fluid level and small adjustments are the key. The kd cable generally doesn’t need replacement unless it started to fray. You should be able to tell if the cam is spring loaded by seeing that it’s not slack and/or pulling on the cable at the throttle linkage.

Hopefully that helps.