Freelander 1 Td4 Jatco 3rd to 4th Flaring, Slip- Solved

The 30k miles TD4 auto 2000 my is exhibiting the above.
When it changes from 3rd to 4th, sometimes, not always, it revs up between changes like its missed a gear or like a clutch slip on a manual.

I'm thinking maybe the 22 year old fluid needs a change but anyone else come across this please??

andyfreelandy said:

When it changes from 3rd to 4th, sometimes, not always, it revs up between changes like its missed a gear or like a clutch slip on a manual.

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Mine did that.
Will it scream to the red line, or does it just speed up momentarily as it changes up?

It just speeds up for a moment before selecting 4th. Doesn't loose drive though.

Not due to old fluid then!!???

Just checked with Pscan. No fault codes.
Not sure if a sticky solenoid would show a code??

Will switch on data logging and try to capture fault on the data.

andyfreelandy said:

It just speeds up for a moment before selecting 4th. Doesn't loose drive though.

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That's called flair, and is a sign of low pump pressure, or clutch wear. Mine started doing that, before it advanced to not selecting 4th at all under throttle, but backing off the throttle allowed it to select 4th for a while, then 4th disappeared altogether, and E4 came up on the dash every time it went into 4th.

Probs worth a fluid change. That could affect pump pressure. At 30k it hopefully isn't wear.
Did wonder if there was a slow to act solenoid.

andyfreelandy said:

Probs worth a fluid change. That could affect pump pressure. At 30k it hopefully isn't wear.
Did wonder if there was a slow to act solenoid.

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At 30k miles, I'd be expecting it to be perfect. Definitely change the fluid a few times, fingers crossed it's just gone off.

Somewhere I saw a table with the solenoids and what they were responsible for in terms of gear changes. Can anyone remind me where it is please??

Today am going to eliminate plug coupler connectors by cleaning, auto ecu connectors and then fluid change.
Will also test solenoids for continuity.
If I knew which solenoids did the 3rd to 4th gear change I could do a pscan data log on a drive but have a feeling that the solenoids may be working just maybe dirty?? This won't show up on a diag.

If anyone has a better memory than me please shout!!

Magic forum this!! As soon as I posted the above I found the table. Jf506E rebuild and repair manual.

Off to test......

andyfreelandy said:

Magic forum this!! As soon as I posted the above I found the table. Jf506E rebuild and repair manual.

Off to test......

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I tested my solenoids by activation using a fused feed through my DMM on 10A current range, direct from the battery positive (the solenoids are grounded through the gearbox case), each solenoid solenoid then clicks as they activate, and give a current reading on the DMM too, which can be checked for constant current draw.

The Pscan log shows all the selection solenoids working correctly as the vehicle is driven. Not all solenoids can be seen on the system. Low clutch, duty and A. B. C. Can be logged against gear selected which has proven all to be OK in the selection circuitry. It doesn't prove the solenoids are working but a resistance check shows all readings OK.
Will change fluid next.
If a solenoid is sticking it may be that I will need to pull then out to clean them.
The fault is more frequent with warm fluid so that might be a clue.

I suppose it depends on when the fluid was changed, if its been changed.
The ATF definitely thins out over time, when compared to new fluid. I like to use Carlube ATF-U, as it's nice and thick, and far exceeds the original ATF specification.

Been using Dexron 3. Seems to be, as you say, above spec too.

andyfreelandy said:

Been using Dexron 3. Seems to be, as you say, above spec too.

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Yes D3 will be above the original LR spec. If you use a synthetic fluid, it has a longer service life, which is why I use ATF-U.

Which solenoids would you look at for a 3rd to 4th change problem?

andyfreelandy said:

Which solenoids would you look at for a 3rd to 4th change problem?

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The 2/4 duty solenoid is normally responsible for hash changes when it fails, so it stands to reason it could also be responsible for overly soft changes, if it's sticking open.

Have you applied power to them to see if you can hear them activating?

Nodge68 said:

Have you applied power to them to see if you can hear them activating?

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Thanks, not yet no. It clearly works as it changes into 4th most times, but when warm it revs but doesn't loose drive as going up hill it keeps speed, just revs go up as it shifts into 4. Can repeat fault in steptronic.

ATF arrived today. Change fluid tomorrow then will operate solenoid as you describe. Would you hear a slow operation perhaps when compared with another??
If that doesn't do it then it is solenoid out time.

I'm wondering if this is a fluid issue. It definitely needs changing, and you'll also be able to tell if the fluid is burnt, which is a sign of clutch slippage, which won't be good.

The solenoids should click very decisively when 12 Volts is applied, and can also be heard to click less loudly when de-energised. From memory they all sound about the same, so any that don't sound like the rest could be suspect. However keep in mind that the higher resistance solenoids don't click quite so loudly, as there's less power driving the armature.

Changed fluid, dark red brown and smelt a bit toasty but very very thin.

Tested solenoids, could only hear the low resistance ones but all operated and took same current within their resistance group.

Took car out for a long run. Think the symptom has changed a bit but still wrong!!

It changes smoother now. 1 to 2 fine, 2 to 3 fine, 3 to 4 changes smoothly then a few seconds after the change it revs then selects 4 again and no problems until the 3 to 4 transition again. No problems changing down in any gears.

Hoped it might be simple!! Will use it gently for a while and see what happens.
Any further suggestions gratefully received.
Can't see that the box is knackered at 31k miles. It has only had this fault for a few hundred miles, fine originally.

A mate has commented that he has seen this fault on low mileage cars used for pottering, usually solenoid he thinks!?

I'd give the box a few hundred miles, if you only did a partial fluid change, do it again after those miles. It could well be the clean fluid will flush out any dirt, which is causing a solenoid to stick.
I can't imagine there's much wrong with a box that has only the equivalent of 3 years motoring.