Tony Kerr

Member
Hi
New to this forum.
I have a 2002 Range Rover HSE 4.4 with 110000 miles on the clock.
I have problem with the reverse on the gearbox.
All forward gears work well and there are no warning messages.
When you put the car in reverse on flat ground the car goes back no problem under acceleration.
When you try to reverse up hill it feels like the clutch is slipping and sometimes clunks.
If you put it in low gear ratio it will reverse perfectly.

The gearbox was changed 4 or 5 years ago and oil and filter was changed a few months ago.

I do not understand how the reverse will work in one mode but not the other.

I will want to get it sorted but not sure where to turn.

Can anyone advise.

Thanks in advance :)
 
How many miles has the box covered since it was replaced?

It will work better in low range as the engine revs are higher, masking any slippage in the box....

I would be tempted to check the gearbox oil level first.
 
Couldn't say how many miles box has doe as was previous owner.

Have checked the oil levels and they are all ok.

If you put the car in reverse and slowly put your foot on the accelerator it is ok , its just purely if you accelerate hard or up -hill in reverse.
 
The problem could be caused by internal leakage in either the C clutch or F brake circuits. Is it worse when hot and better when cold, or does the fluid temperature make no difference?

Phil
 
The problem could be caused by internal leakage in either the C clutch or F brake circuits. Is it worse when hot and better when cold, or does the fluid temperature make no difference?

Phil
The temperature does no really make any difference.
Have been on long journeys and short and the car does same thing each time in reverse.
 
Couldn't say how many miles box has doe as was previous owner.

Have checked the oil levels and they are all ok.

If you put the car in reverse and slowly put your foot on the accelerator it is ok , its just purely if you accelerate hard or up -hill in reverse.
(Sorry if this seems insulting or sucking eggs) but you have checked the level correctly?

Engine running, Gearbox at 40degC, go through selections pausing briefly in each one and back to park, then check level...??
 
(Sorry if this seems insulting or sucking eggs) but you have checked the level correctly?

Engine running, Gearbox at 40degC, go through selections pausing briefly in each one and back to park, then check level...??
Lol, Hi yes I had my garage check the oil who changed the oil. They did it the way you are stating.
I even took it elsewhere to double check.
 
Lol, Hi yes I had my garage check the oil who changed the oil. They did it the way you are stating.
I even took it elsewhere to double check.
Fair game, have to ask and all that....:D

Bemble (also known as RRPhil - a stonking legend) is a master rebuilder of the ZF5 'boxes so I would certainly heed and act on any advice he gives....

Certainly sounds like it is an 'internal to the box' problem as he says, one or t'other hydraulic operated packs is slipping...the more gentle approach to applying power will allow the friction discs to maintain adhesion and allow drive....the harder acceleration will promote slippage in the friction discs making drive seem lost......really gunning it, will cause slippage, but the faster rotating components will make it seem like it is behaving...but this can cause massive over heating to the clutch plates, friction discs and eventually overheat the 'cages' (the bits that hold the clutch and brake packs together)...this can be bad in the long term!
 
Fair game, have to ask and all that....:D

Bemble (also known as RRPhil - a stonking legend) is a master rebuilder of the ZF5 'boxes so I would certainly heed and act on any advice he gives....

Certainly sounds like it is an 'internal to the box' problem as he says, one or t'other hydraulic operated packs is slipping...the more gentle approach to applying power will allow the friction discs to maintain adhesion and allow drive....the harder acceleration will promote slippage in the friction discs making drive seem lost......really gunning it, will cause slippage, but the faster rotating components will make it seem like it is behaving...but this can cause massive over heating to the clutch plates, friction discs and eventually overheat the 'cages' (the bits that hold the clutch and brake packs together)...this can be bad in the long term!
Thats great anything will help , many thanks
 
Did somebody say valve block?

I swear every time I don't visit the forum for couple of days the first post on top of the RR forum is always titled "L322 gearbox problem".
 
6 posts in, your joy just began believe me. I remember when I filled the registration form many many repairs ago :D You in safe hands. Good luck with your box.
 
6 posts in, your joy just began believe me. I remember when I filled the registration form many many repairs ago :D You in safe hands. Good luck with your box.
Oh believe me this is another on the list of repairs done and due to be done. lol
 
Reverse is very ‘direct’ in a hydraulic control sense because it doesn’t require the activation of any of the valve body solenoids. It is designed this way so that reverse is still available in transmission failsafe mode in the event of an electronic/electrical failure. The shift lever mechanism acts directly on the manual valve which guides pressure straight to the C & F clutches.

F clutch piston seal failures, while commonplace in the early years of the 5HP24, were sorted by the time the L322 came along

F-brakepiston1_zps2bf08bf1.jpg


so I’d be more inclined to suspect a fault in the C clutch circuit as this has four O-ring static seals, 2 PTFE dynamic seals and 2 phosphor bronze bushes (which also act as running seals) in the feed circuit. If these bushes are worn, or any of the O-rings split, or the PTFE seals worn, the resulting internal leakage could prevent the C clutch engaging fully.


A quick test of the C clutch circuit would be to temporarily unplug the 16-pin electrical connector on the back of the transmission to deliberately put the transmission into failsafe mode

16%20pin%20multiplug_zpsvs3ikloh.jpg


The EDS1 solenoid will then apply full pressure to the modulation valve whose pressure acts on the underside of the C clutch accumulator/damper piston, supplementing the spring force. This pressure prevents the C clutch accumulator moving against its spring preload which otherwise would allow the piston to move down its bore and cause the clutch to be fed through a Ø1.0mm orifice. This restriction in flow will prevent the C clutch engaging fully if there’s leakage in the circuit.

This accumulator/damper system is the reason why reverse engages smoothly from stationary by providing fast initial clutch fill and then a restricted rise in clutch pressure followed by unrestricted flow once again when the damper piston bottoms out. The A clutch also uses the same damping system for smooth forward gear engagement from stationary.

A%20amp%20C-clutch%20Dampers_zpsdfzwrcyz.jpg


Summary
1) Disconnect electrical connector, transmission will go into failsafe mode - see if car will now reverse properly.
2) Reconnect electrical connector, failsafe will disappear – check car will no longer reverse properly, like before.
3) Report back.

Phil
 
See....fecking legend.....told ya.....

Well Done once again Phil for a fantastic and informative post.....your legendary knowledge on these things astounds me....God love you my good man, if he feels it right to do so.!! :D:D
 
Reverse is very ‘direct’ in a hydraulic control sense because it doesn’t require the activation of any of the valve body solenoids. It is designed this way so that reverse is still available in transmission failsafe mode in the event of an electronic/electrical failure. The shift lever mechanism acts directly on the manual valve which guides pressure straight to the C & F clutches.

F clutch piston seal failures, while commonplace in the early years of the 5HP24, were sorted by the time the L322 came along

F-brakepiston1_zps2bf08bf1.jpg


so I’d be more inclined to suspect a fault in the C clutch circuit as this has four O-ring static seals, 2 PTFE dynamic seals and 2 phosphor bronze bushes (which also act as running seals) in the feed circuit. If these bushes are worn, or any of the O-rings split, or the PTFE seals worn, the resulting internal leakage could prevent the C clutch engaging fully.


A quick test of the C clutch circuit would be to temporarily unplug the 16-pin electrical connector on the back of the transmission to deliberately put the transmission into failsafe mode

16%20pin%20multiplug_zpsvs3ikloh.jpg


The EDS1 solenoid will then apply full pressure to the modulation valve whose pressure acts on the underside of the C clutch accumulator/damper piston, supplementing the spring force. This pressure prevents the C clutch accumulator moving against its spring preload which otherwise would allow the piston to move down its bore and cause the clutch to be fed through a Ø1.0mm orifice. This restriction in flow will prevent the C clutch engaging fully if there’s leakage in the circuit.

This accumulator/damper system is the reason why reverse engages smoothly from stationary by providing fast initial clutch fill and then a restricted rise in clutch pressure followed by unrestricted flow once again when the damper piston bottoms out. The A clutch also uses the same damping system for smooth forward gear engagement from stationary.

A%20amp%20C-clutch%20Dampers_zpsdfzwrcyz.jpg


Summary
1) Disconnect electrical connector, transmission will go into failsafe mode - see if car will now reverse properly.
2) Reconnect electrical connector, failsafe will disappear – check car will no longer reverse properly, like before.
3) Report back.

Phil
Phil

I had a week of the car reversing perfectly hence the time its taken me to do this.

I eventually got it today to start playing up in reverse.

Disconnected the plug and it reversed properly but started jumping at higher revs ie the revs started going up and down (best way I can describe it), lower revs was perfect.
Reconnected the connector and it went back to slight jump occasionally and a bit slipping.
Rechecked fluid again today and it is correct.

Hope this is the info you need.

Regards

Tony
 
Hi Tony,

If you select 1st gear in manual (steptronic) mode do you get engine braking? (showing that the F-clutch is working properly)

If so, it does sound like you have an internal leak in the C-clutch circuit, which unfortunately would mean that the transmission would have to come apart to fix it. Because of the costs involved it’s often difficult to decide whether or not just to put up with it. I fixed a 5HP24 for a guy with a Range Rover with exactly the same issue as yours (though his was even worse by the sound of it) and he’d managed with it like that for 9 months. He said he’d become an expert at parking the car so that he wouldn’t need reverse and it was a hard habit to break even after I’d fixed his ‘box.

Phil
 
Hi Tony,

If you select 1st gear in manual (steptronic) mode do you get engine braking? (showing that the F-clutch is working properly)

If so, it does sound like you have an internal leak in the C-clutch circuit, which unfortunately would mean that the transmission would have to come apart to fix it. Because of the costs involved it’s often difficult to decide whether or not just to put up with it. I fixed a 5HP24 for a guy with a Range Rover with exactly the same issue as yours (though his was even worse by the sound of it) and he’d managed with it like that for 9 months. He said he’d become an expert at parking the car so that he wouldn’t need reverse and it was a hard habit to break even after I’d fixed his ‘box.

Phil
Phil

Tried 1st gear in manual and yes had engine braking.

I could put up with it but to be honest with the amount of work I have done so far I would most likely want to get it repaired, bit of a perfectionist lol.

If there is an option to get the box repaired then I would look at that to be done if you have an idea of price.

I can always take the rangy of the road to remove the box as its coming to summer holidays so kids are off school (god help me :0 ) so I can use our other car.

If you want to email me direct to discuss this please contact me on given

Regards

Tony
 
Last edited:
Okay Tony, I've got your address and I'll email you. You might want to delete your email address from your post now so that you don't receive loads of spam.
Phil
 

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