Automatic gearbox issue - jerk - downshift

[Stanley008]

Hi,
any idea what could cause jerk/small kick in automatic gearbox when downshifting? It is more obvious when the engine/gearbox is cold(less obvious or it even dissapears when the gearbox gets warm) and the thing happens only when downshifting and it seems that it only happens from 3 to 2nd gear around 40kmh/ 25mph? You can hear and feel the jerk / kick pretty obvious. But only from 3 to 2nd gear, other gears are OK. Any idea? Solenoid? Or it is just completely failing? The gearbox has 120 000km/ 75000 mil .

[steve-45]

When was the last time the gearbox oil was changed ?

[SD1too]

Originally Posted by Stanley008

Solenoid?

Possibly, but rule out the basics first. Engine tune can have a surprisingly odd effect upon automatic transmissions luring the unsuspecting owner into believing that the gearbox is about to fail. Has the fluid been changed recently? Is the level correct?

Or it is just completely failing?

No. There is always a reason for a fault, it’s just a master of finding it. Rough changes are usually related to fluid or the engine not running properly.

I notice your mysterious location. Are you based outside the UK?

Simon

[Stanley008]

Originally Posted by steve-45

When was the last time the gearbox oil was changed ?

It was not as it should be lifetime and many services do not want to change it and even don't know..... many of the jatco automatic gearboxes failed because not knowing how to properly change the oil.

I wan't to fix the jerk and than find someone who nows what he is doing to change the oil. Not worth to change the oil if the gearbox is failing... 200-300 pounds down the trash.

And the issue is only between 3 - 2nd gear = should not be related to oil, otherwise other gears would have issues too.

[Stanley008]

Originally Posted by SD1too

Possibly, but rule out the basics first. Engine tune can have a surprisingly odd effect upon automatic transmissions luring the unsuspecting owner into believing that the gearbox is about to fail. Has the fluid been changed recently? Is the level correct?

No. There is always a reason for a fault, it’s just a master of finding it. Rough changes are usually related to fluid or the engine not running properly.

I notice your mysterious location. Are you based outside the UK?

Simon

Oil was not changed as mentioned above your post. There is only 1 rough change between 3-2nd gear... it is obvious when slowing down to a junction, no need to be on the gas pedal, slowly braking and suddenly a jerk / kick in the gearbox around 40km/25mph.

I am faaar away from UK, Czech Republic .

[rustymotor]

Unless there is an oil leak the level won't be a problem. Could be sticking valve or partial blockage etc. You need to know when the oil was last changed? Oil change is the least cost option to try but, it has to be the correct ATF, correct temp (35 to 45' C ) for checking levels and to ensure the oil is properly distributed around the box, go from P through all the gears with a pause between each and back to P then recheck level via the level plug.

[Stanley008]

I'll probably check the solenoids first.... but I can't really see the right connector where it should be checked? Where is it hidden?

I've already got the scheme with pins and related resistance from a land rover website for the exact same auto box - should be the same.

It seems like the connector is all the way down.... bit of a an issue in 2.5V6.

[rustymotor]

Check this thread out may help:

LINK

[Stanley008]

Originally Posted by rustymotor

Check this thread out may help:

LINK

It seems like the most common problem is 2/4 Brake Duty Solenoid.

Any idea If I will have access to the solenoid conector the 18pin after removing the air filter box completely? Or do I have to go under the car?

I was looking for the connector but from top.... no chance, even idea where it exactly lies.

[rustymotor]

Hi, sorry I have no idea about that but, there will be someone with more knowledge than me come along I'm sure..