Thread: Autobox hard changes after Ashcroft torque converter upgrade

Oops, didn't see that. Yeah that's a questionable choice

I'd try resetting the adaptive values as well, you mentioned earlier you had a Nanocom...they will do that just fine.

But that said, it's a long shot as it will re learn as you go along anyway, but it does take some time.

As mentioned, probable that some material had got where it shouldn't.

I read you said it was full, wowed you get the correct level?

Heres an excellent video on servicing replacing fitter etc and the correct fill process Atlantic British Presents: Transmission Service Performed on Land Rover Discovery Series II - YouTube

Originally Posted by simonmelb

So you installed a new torque converter in the same transmission?

Was the transmission disassembled, inspected and rebuilt (again).

I would imagine the cause to be the failed clutch material you found has contaminated parts of the tranny ( valve body etc) causing harsh shifts.

Some Good rebuilders won’t even warrant their work unless you change the transmission cooler due to possible contamination for example.

Originally Posted by aaact1

I really know nothing about autoboxes, but after reading the forums and seeing suggestions for others with similar harsh change issues to rebuild the valve body I watched an instructional video on how to do it. Now that I know what it looks like in there, I'd have to agree with you - it is the likely issue. All we did was flush the oil cooler lines, dump the tranny fluid, and replace the filter - so it is likely still floating around in the galleries and causing drama. Now to decide whether to pay for it to be done, or have a crack at it myself...

I too think the problem is due to friction material floating around in the box, and as it moves around you might find the fault changes, or more faults appear, it pro'ly needs a full rebuild.

i recall that in the old days auto transmission had a vacuum device fitted to make the gearshift changes smoother. There may be something in the tranny that is built for this purpose. You will need to have a read of a workshop auto rebuild manual and see if you can find the cause of the harsh shifting.
are the gearshifts harsh all the time or only under hard accelaration ? at what revs are the shifts occuring ?
Have you contacted Ashcrofts to see if they have an ideas as to what is occuring ?

Ian
Bittern

Originally Posted by ian4002000

i recall that in the old days auto transmission had a vacuum device fitted to make the gearshift changes smoother. There may be something in the tranny that is built for this purpose. You will need to have a read of a workshop auto rebuild manual and see if you can find the cause of the harsh shifting.
are the gearshifts harsh all the time or only under hard accelaration ? at what revs are the shifts occuring ?
Have you contacted Ashcrofts to see if they have an ideas as to what is occuring ?

Ian
Bittern

The old day transmissions were not electronically controlled. So there were two ways to control transmission pressures.

It was either using a cable which was often incorrectly called a kick down cable , or a vacuum modulator was used.

Through engine vacuum, the tranny could work out throttle position to adjust tranny pressure to suit.

So no, you won't find one in or on a ZF.

Hi all,

Thanks for your input and assistance with this - we got it going today. I ordered a secondhand valve body from a rover wrecker who suggested it would be in good working order. The plan was to simply remove mine and fit the replacement and see what difference it makes. The secondhand unit wasn;t looking so crash hot - the tranny fluid had turned black, and there was quite a bit of grey sludge and metal filings. When we removed my valve body, it looked immaculate. We decided to get to work on that instead. We didn't separate the two halves to reveal all the journals and plungers, we just removed the solenoids and the journal/plunger assemblies that accompany those. We tested each solenoid (all working), and removed the plungers but they all seemed clean and working smoothly. We then found what we believed to be the issue - the pressure control solenoid has a very small mesh filter in the end, which was completely blocked with the fibrous material from the old torque converter. We cleaned that out thoroughly, put everything back together, replaced the tranny fluid, and closed her back up. We also replaced the XYZ inhibitor (which was not always recognising drive, and not allowing me to engage 1st), and reset the adaptive values. Great success - it drives like a dream now. To anyone who hasn't done the Ashcroft TC upgrade, I really highly recommend it - she drives like a different vehicle...smoother, more pickup, more responsive...just far more pleasant to drive. I am certain to get a speeding ticket!

Thanks again, your suggestions really helped steer me in the right direction.

Originally Posted by aaact1

Hi all,

Thanks for your input and assistance with this - we got it going today. I ordered a secondhand valve body from a rover wrecker who suggested it would be in good working order. The plan was to simply remove mine and fit the replacement and see what difference it makes. The secondhand unit wasn;t looking so crash hot - the tranny fluid had turned black, and there was quite a bit of grey sludge and metal filings. When we removed my valve body, it looked immaculate. We decided to get to work on that instead. We didn't separate the two halves to reveal all the journals and plungers, we just removed the solenoids and the journal/plunger assemblies that accompany those. We tested each solenoid (all working), and removed the plungers but they all seemed clean and working smoothly. We then found what we believed to be the issue - the pressure control solenoid has a very small mesh filter in the end, which was completely blocked with the fibrous material from the old torque converter. We cleaned that out thoroughly, put everything back together, replaced the tranny fluid, and closed her back up. We also replaced the XYZ inhibitor (which was not always recognising drive, and not allowing me to engage 1st), and reset the adaptive values. Great success - it drives like a dream now. To anyone who hasn't done the Ashcroft TC upgrade, I really highly recommend it - she drives like a different vehicle...smoother, more pickup, more responsive...just far more pleasant to drive. I am certain to get a speeding ticket!

Thanks again, your suggestions really helped steer me in the right direction.

Really well done, I admire that.

Is your Td5 engine modified? Which mods?