E

eldescans

senior member
Hi been having problems with my box for sometime now I have asked for help before but have not received a satisfactory answer the problem is I have no drive in any gears first thing in the morning for about 2 to 3 minutes then it will suddenly drive and everything is OK until I stop and leave the car for any amount of time and then the same thing happens again no drive for about 2to 3 minutes has anyone any ideas as to what might be the problem it has been suggested to me that it might be either the govenor or the pump, at the moment I have the valve block off looking for possible faults any help would be very much appreciated. Also could anyone point out to me where the govenor is thanks
 
If it's a P38 there is no governor. Oil pressure is controlled by one of the valves. James Martin is your man.
 
Engagement is done manually only the changes are electronic. If you have the valve block off good luck you will need it if you open it. Everything in there HAS to go back in the same place, different rate springs Etc. Don't even think about it unless you have a service sheet if you have not done one before. Favourite would be a blocked filter under normal circumstances. But if it still does it when oil is warm maybe you have a sticking shuttle valve in the block. What colour was the fluid?
 
Unless I have missed something, my ZF diagnostic guide tells me that selection is manual but engagement of all gears is electronic via the ECU and the solenoids. The only direct manual activation is the parking pawl?

Eldescans, I can send you the ZF4HP22/24 diagnostic guide, PM me with an Email address if you want it.
 
If a fluid /filter change doesn't cure it, go to a gearbox specialist. It costs but it's cheaper than breaking your gearbox, don't mess around with autoboxes unless you know what you're doing
 
Datatek said:
Unless I have missed something, my ZF diagnostic guide tells me that selection is manual but engagement of all gears is electronic via the ECU and the solenoids. The only direct manual activation is the parking pawl?

Eldescans, I can send you the ZF4HP22/24 diagnostic guide, PM me with an Email address if you want it.
Click to expand...

No Keith there is a manual valve that engages drive and sends oil to the valve block. The selected drive 1 2 3 D R positions are sent to the ECU electronically. But the manual valve engages drive in all positions except park and neutral.
 
Saint.

I think I have seen your old p38 advertised by the dealer you p/x with. He is asking £3k.

Hope the L322 is still being enjoyed..
 
stemac33 said:
Have a look here


Are you having a laugh.:)

Torque converter housing
On 2.5 litre Diesel models a 260 mm (10.2 in)
diameter torque converter is used. On 4.0 and 4.6 litre
petrol models a 280 mm (11 in) diameter torque
converter is used. On 4.6 litre petrol models up to
99MY the torque converter is longer than the torque
converter used on 4.0 litre petrol models. From 99MY,
both the 4.0 and 4.6 litre petrol models use the shorter
torque converter previously used on up to 99MY 4.0
litre models.
The torque converter housing attaches the gearbox to
the engine and contains the torque converter. The
torque converter is connected to the engine drive
plate and transmits the drive from the engine to the
gearbox input shaft. When engaged, a hydraulic
lock-up clutch in the torque converter prevents
slippage, to give a direct drive from the engine to the
gearbox for improved efficiency.
Intermediate plate
The intermediate plate supports the gearbox input
shaft and provides the interface between the
transmission fluid pump and the lubrication circuit.
The pump attaches to the front of the intermediate
plate and is driven by an impeller in the torque
converter. The pump pressurises transmission fluid
drawn from the sump on the gearbox housing. The
pressurised fluid then circulates through the torque
converter and gearbox housing components for
cooling, lubrication and gear shift purposes. Ports
around the outer periphery of the intermediate plate
provide the inlet and outlet connections to the fluid
cooler and a pressure take-off point for servicing.
On ZF4HP24 gearboxes, the intermediate plate is
15 mm (0.6 in) thicker than fitted to the ZF4HP22
gearbox to accomodate a larger fluid pump unit. To
compensate for the increased length of the
intermediate plate, the rear extension housing is
15 mm (0.6 in) shorter than that fitted to the ZF4HP22
gearbox.
Gearbox housing
The gearbox housing contains two epicyclic gear sets
on input and output shafts. Hydraulic clutches on the
shafts control which elements of the gear sets are
engaged, and their direction of rotation, to produce the
P and N selections, four forward gear ratios and one
reverse gear ratio.
Gear ratios
Gear Ratio
1st 2.480:1
2nd 1.480:1
3rd 1.000:1
4th 0.728:1
Reverse 2.086:1
The lock-up and brake clutches are operated by
pressurised transmission fluid from the valve block in
the sump. A manual valve and four solenoid valves,
also known as Motorised Valves (MV), control the
supply of pressurised transmission fluid from the valve
block:
• The manual valve controls the fluid supply for P,
R, N and D selector positions. The four solenoid
valves operate accordingly to operate shift
control, lock-up and shift quality.
• Solenoid valves MV 1 and MV 2 control the
supplies that operate the brake clutches for shift
control. They are also used to prevent accidental
engagement of reverse when moving forwards
and a forward gear when moving backwards.
• Solenoid valve MV 3 controls the supply that
operates the lock-up clutch.
• Solenoid valve MV 4 modulates the pressure of
the supplies to the brake clutches, to control shift
quality.
Operation of the manual valve is controlled by the
selector lever assembly. In the gearbox, a selector
shaft engages with the manual valve. The selector
shaft is connected to the selector lever assembly via
the selector cable and a selector lever on the left side
of the gearbox. The selector shaft also operates a
mechanism that locks the output shaft when P is
selected.
Operation of the solenoid valves is controlled by the
EAT ECU.
Click to expand...
 
Last edited:
many thanks for your replies sorry I havent answered before but I have a back problem at the moment and it hurts to even think about anything. Wammers I cannot understand what you mean by splitting the valve block I have taken mine off and all there seems to be is solenoid valves no springs or anything else and no way of splitting it. Could you please tell me where the shuttle valve is so that when I am able I can check it The only thing I have ever found wrong is when I did the first oil change someone had fitted the filter without the O ring and so I dont know if dirty oil has been pumped through the system. I need to try and sort it by the 16th as it has to go for an MOT
 
wammers said:
No Keith there is a manual valve that engages drive and sends oil to the valve block. The selected drive 1 2 3 D R positions are sent to the ECU electronically. But the manual valve engages drive in all positions except park and neutral.
Click to expand...

That's what I tried to say Tony, not very well maybe but it amounts to the same, the clutches for the gears are operated electronically. No matter what you do with the lever, if the engagement solenoids stick/fail it will not move:)
 
Datatek said:
That's what I tried to say Tony, not very well maybe but it amounts to the same, the clutches for the gears are operated electronically. No matter what you do with the lever, if the engagement solenoids stick/fail it will not move:)
Click to expand...

Drive engagement to clutch 4 fwd and clutch 5 rev are selected manually. Drive to 4 and 5 is disengaged manually in P and N. All others are selected electronically by the ECU as required. :)
 
Last edited:
Hi All,

I have this exact same problem with my P38, have changed the oil and filter, but made no difference...

Did you resolve it?

Regards,

AB.
 
Wammers,
That is interesting info on the gearboxes.

It nicely summarises what I had to find out the hard way doing a HP22/HP24 swap.
Where did it come from might I ask?
 
eldescans said:
many thanks for your replies sorry I havent answered before but I have a back problem at the moment and it hurts to even think about anything. Wammers I cannot understand what you mean by splitting the valve block I have taken mine off and all there seems to be is solenoid valves no springs or anything else and no way of splitting it. Could you please tell me where the shuttle valve is so that when I am able I can check it The only thing I have ever found wrong is when I did the first oil change someone had fitted the filter without the O ring and so I dont know if dirty oil has been pumped through the system. I need to try and sort it by the 16th as it has to go for an MOT
Click to expand...
missing o ring would mean pump would find it harder to suck oil up from sump everytime it was switched off
 
Hi Datatek,

Do you know what is causing the problem? If it is common, and the gearbox is fine other than this fault, i would have thought that someone would be offering a 'quick' fix....

Regards,

AB.
 
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