Gearbox problem possibly........

Hope I re-posted this to the right section as advised by a gracious member

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Original post.

Hi, Have a problem.

I swapped one of my old S Type jags for a lovely looking P38 2001. Engine was diabled and had been for standing for six months. Got it home, fixed the drivers door lock and micro switches. Programmed new keyfob, cleared all warnings, WIndows etc. Coolant leak on u bend at rear of head.
Engine and vehicle really nice.

Problem is this.......It revs high in all gears and slows down on inclines as if slipping. Cleaned and checked filter, drained one load of ATF off. Refilled with correct procedure and slightly better but drive is not good.

My mate assures me it was fine when he parked it up. Oil was really dark brown but no great deposits of sludge or metals in sump.

Can standing cause the Gearbox Ecu's to play up or is there some possible grounding problems. I read somewhere that head temps sensors can cause all sorts of problems, is this correct in the cae of the drive.

Hope the box is not jiggered......only 102k miles and vehicle is in great looked after shape.

No.....not plugged in to get any gearbox codes as yet. obd is all clear using my icarsoft but it does not access gearbox unfortunately.

Any suggestions..........(Dont tell me new Box) not yet.......wrong time for that cost LOL).

Best wishes.

Best to change oil several times as tc stores some and this does not come out . About 3 changes then new filter with bottle of lucas transmission fix should help.

You need to change the filter.
Possible that the A-clutch (forward gears) is badly worn.
Does it reverse without any issues or is that slipping as well?

The P38 uses the ZF4HP24, but these that deal with the ZF4HP22 are worth a read. I found them both useful when I did my RRC's HP22:
http://www.cowdery.org.uk/zf.php
http://bmwe32.masscom.net/moswald/zf4hp22_rebuild/zf4hp22_rebuild.html

These were good for parts - order by phone - and the exploded diagrams are handy:
https://jpat.co.uk/zf.html#

Rubberknees said:

Best to change oil several times as tc stores some and this does not come out . About 3 changes then new filter with bottle of lucas transmission fix should help.

Click to expand...

Hi,

Thanks and yes intended to do as you advised. Weather is of course impeding that right now but will get onto that as soon as.

Thanks matey.

New Fluid and try some Lucas Transmission Fix fluid....could be a little sticky in there and needs a bit of loosening up!

Ratae said:

You need to change the filter.
Possible that the A-clutch (forward gears) is badly worn.
Does it reverse without any issues or is that slipping as well?

The P38 uses the ZF4HP24, but these that deal with the ZF4HP22 are worth a read. I found them both useful when I did my RRC's HP22:
http://www.cowdery.org.uk/zf.php
http://bmwe32.masscom.net/moswald/zf4hp22_rebuild/zf4hp22_rebuild.html

These were good for parts - order by phone - and the exploded diagrams are handy:
https://jpat.co.uk/zf.html#

Click to expand...

Hi and thanks for the reply.

Reverse appears to operate ok but of course not been reversing it like driving forward.

I'll take a look at the info you sent me.

Maybe just do the few oil changes. (I removed the filter and remanufactured it. The micron guaze in the filter had nothing but very very light substance in it. The oil was deep red but nothing like burnt sludge or contaminated with anything nasty).

Maybe my friend is not telling me the whole truth but he drove it the other day and said it did not drive like that prior to the keyfob falling apart on the forecourt and locking him out of starting the engine. He moved it onto a trailer some 15 -02- feet in nuetral......no fuse in location 11 as he did not know). It stood then for six months at his ex's until we fetched it).

My wonder is as to whether the TC is NOT locking in so that it's relying on the TC being in friction through the oil and thus not locking it is taking more rev's to get the speed.

So hopefully by more flushes and the additive advised on here perhaps it might just get the valve block or the TC to react better. It just missed that "OOOMPH" but that description in no way is meant to be against the engine performance. It sounds really well. Likewise if a valve is either not opening or closing off properly in the valve block then the whole hydraulic train could suffer pressure loss. Giving me the same outcome.

I'm a bit of a fiddler (Ex Toolmaker/Machinist) and not frightened to strip the whole box if necessary .......I would have thought that the condition of the vehicle, how it appears to have been kept and maintained etc, it would have provided more than 102 thousand miles before the box packs in through wear. But then again I have no idea of the previous owners or it's full service history. (Certainly don't subscribe to manufacturers claiming lifetime operation without services LOL).

Thanks for the links as well.

Just as an update.......Traction control light and the dash computer readout threw up Traction Control failure.......first time it's done that. Wonder if this is linked also ?

Regards.

Gonna have to get a read methinks and soon. Yet another expensive device that I'll have to keep the cost of from the missus or I'm toast. LOL.

Trac Control Light is commonly due to low battery charge

Saint.V8 said:

Trac Control Light is commonly due to low battery charge

Click to expand...

Thanks once more. Yep. Sitting fiddling and not running charging etc is not helping ......I have run it down to be fair.
Thanks.

The temp sender for the ECU on the side of the head can cause the torque lockup to engage and disengage but only at 50mph and over. I replaced both after one sensor had a loose head and the other had green stains around it.
Get all the wheels off the ground to check you don't have any of the running gear or brakes sticking??

It's not in sports mode is it?

Mark Piercy said:

The temp sender for the ECU on the side of the head can cause the torque lockup to engage and disengage but only at 50mph and over. I replaced both after one sensor had a loose head and the other had green stains around it.
Get all the wheels off the ground to check you don't have any of the running gear or brakes sticking??

Click to expand...

Mmmm....Interesting. It had a massive coolant leak which I traced to the U bend pipe at the back of the head.......used my hand and boy was it hot.....LOL. Maybe ssome overheat could have jiggered those senders. Worth changing as well. Will check the sticking of running gear as you suggest too.

Thanks.

Wazzajnr said:

It's not in sports mode is it?

Click to expand...

Hi.....

No it's not in sports mode if the indicators on the shifter are correct.......
My understanding of the lights on the shifter is as follows.
On Startup......Gated to High ratio, the manual light is not lit but when you press the sport mode it lights red.
If you go over to Low ratio the sport light does not light but you can press the switch so the manual light lights and this illuminates only in Low ratio.
All lights on the shifter operate fine and the dash menu light is exactly replicating the gearbox with no discrepancies.

Ordered two packs of the Lucas Magic oil this afternoon ready to the second change of oil as advised by members on here.

My garage pal is trying to get a reader to read the transmision ECU's which will help rule out some stuff I suppose.

Probably I was wild off the mark regarding the TC especially if the lock up is at 50mph as suggested earlier today.

Cheers. matey.

Try this also.
Not an official test and not for very long either!!
In drive and running.
Handbrake on.
Foot on brake as well.
Try very briefly to rev the engine while in gear past 2000rpm. It should resist like hell.
If it surpasses 2000rpm with ease then you may well have issues in the box.
Please do not repeat this test needlessly, it may well lead to damage as the box is pressurised ready to move the bus!!!

On flat level ground the car should creep forward with no throttle imput and brake off etc..

Try parking the car on a hill in D and see if the G/box can hold her stationary without rolling back, no throttle just on idle.

If it rolls then suspect a worn box, and if it does check to see at what RPM she stops and begins to move forward and vice versa.

You'll need Nanocom or similar to read codes. Full battery volts or you'll be chasing ghosts.

Is this a diesel?

Mark Piercy said:

Try this also.
Not an official test and not for very long either!!
In drive and running.
Handbrake on.
Foot on brake as well.
Try very briefly to rev the engine while in gear past 2000rpm. It should resist like hell.
If it surpasses 2000rpm with ease then you may well have issues in the box.
Please do not repeat this test needlessly, it may well lead to damage as the box is pressurised ready to move the bus!!!

Click to expand...

Will Do.........(Again)......funny you should suggest that. I did it last night but got interrupted ...........From the short try I did, it appeared to resist fiercely.

Will get on that right away.

Best Wishes.

Grrrrrr said:

You'll need Nanocom or similar to read codes. Full battery volts or you'll be chasing ghosts.

Is this a diesel?

Click to expand...

Thanks matey. (nanocom.....sounds expensive). I've heard the name whilst reading different threads.

Yes it's a diesel 2.5.

Regards.

Henry_b said:

On flat level ground the car should creep forward with no throttle imput and brake off etc..

Try parking the car on a hill in D and see if the G/box can hold her stationary without rolling back, no throttle just on idle.

If it rolls then suspect a worn box, and if it does check to see at what RPM she stops and begins to move forward and vice versa.

Click to expand...

Hi, On the level it does. Not tried that tbh on an incline so will do. Plenty of inclines on Biddulph Moor where I live LOL.

Regards.

Might be a member with diag nearby on the Landyzone International Rescue Map. Have a search on there.

Diesel will have the HP22 unless someone has swapped it.

When it slows on the incline do the revs slow too? Thinking lift-pump although changing fuel filter and air filter and flushing the intercooler might help. There's a How To in the Technical Section by Wammers on how to check lift pump is delivering enough fuel.

Ratae said:

You need to change the filter.
Possible that the A-clutch (forward gears) is badly worn.
Does it reverse without any issues or is that slipping as well?

The P38 uses the ZF4HP24, but these that deal with the ZF4HP22 are worth a read. I found them both useful when I did my RRC's HP22:
http://www.cowdery.org.uk/zf.php
http://bmwe32.masscom.net/moswald/zf4hp22_rebuild/zf4hp22_rebuild.html

These were good for parts - order by phone - and the exploded diagrams are handy:
https://jpat.co.uk/zf.html#

Click to expand...

Only the 4.6 uses the HP24, the diesel and the 4.0 use the HP22e