Concerns about resetting transmission adaptive values

[denver6161]

Just curious to see if anyone has any opinions or advice on this matter. I have my 06 LR3 in the shop currently for a look over, oil change, transfer fluid change, etc. I had mentioned to them that I was experiencing a 'thunk' like noise and knock when coasting towards a stop light and then accelerating. It seems pretty common and I assumed that the truck needed to have the software updated as mentioned in other threads. Spoke with the shop today and they noted that they had completed the software update and while there was a lot of improvement the thunk issue was still evident. They recommended resetting the adaptive values on the transmission itself. The truck has 90,000 miles on it and I completed the transmission fluid change approximately 1300 miles ago.

It feels weird to reset the learned transmission adaptive values on a truck with 90,000 miles. Is this a minor risk? Major risk? Other than this minor thunk (and the need for a new compressor drier) the truck is running brilliantly.
Any thoughts or opinions you all could offer? I can still call the shop tomorrow morning and not have them complete the service.

Thank you in advance.

 

[soflorovers]

Just curious to see if anyone has any opinions or advice on this matter. I have my 06 LR3 in the shop currently for a look over, oil change, transfer fluid change, etc. I had mentioned to them that I was experiencing a 'thunk' like noise and knock when coasting towards a stop light and then accelerating. It seems pretty common and I assumed that the truck needed to have the software updated as mentioned in other threads. Spoke with the shop today and they noted that they had completed the software update and while there was a lot of improvement the thunk issue was still evident. They recommended resetting the adaptive values on the transmission itself. The truck has 90,000 miles on it and I completed the transmission fluid change approximately 1300 miles ago.

It feels weird to reset the learned transmission adaptive values on a truck with 90,000 miles. Is this a minor risk? Major risk? Other than this minor thunk (and the need for a new compressor drier) the truck is running brilliantly.
Any thoughts or opinions you all could offer? I can still call the shop tomorrow morning and not have them complete the service.

Thank you in advance.

So...my advice may not apply directly to you, but I had the same question because I have a separate transmission/drivetrain issue where the revs begin to flutter/bounce at constant throttle around 1500 rpm or so when in "drive". When I switch to manual shifting, the fluttering/inconsistent revs disappear; that leads me to believe that this is due to the transmission adapting to some drivetrain issues.

I spoke with a tech regarding resetting adaptations and I was advised against it with my current mileage (174k). However, the tech advised me against it because he's seen trucks with as low as 40k miles which respond poorly to resetting the adaptive values. Ultimately, I may reset mine and see what happens. I'm curious to see what everyone else on here has to say. My advice was received from a respected LR tech who is very familiar with the AJV8 powered vehicles and has been working on them for over a decade. As such, I tend to weigh his advice more than my own personal guestimates.

 

[Carson G]

I wouldn’t reset the adaptations unless I was changing the mechatronics assembly. Or at a minimum the solenoids.

 

[RR876]

I had a thunk for about 70k miles of ownership that only went away when I changed the solenoids. The solenoids eventually failed putting my vehicle into a limp mode.

I highly recommend changing the solenoids when any high mileage vehicle has a transmission service, if they have not been changed previously. They are messy but straight forward to change. The cost of the solenoid kit was about the same as the oil and filter for a service which you need to replace for a solenoid change anyway.

 

[soflorovers]

I wouldn’t reset the adaptations unless I was changing the mechatronics assembly. Or at a minimum the solenoids.

Could you explain why? Genuinely curious. What occurs when the adaptations are reset?

 

[soflorovers]

I had a thunk for about 70k miles of ownership that only went away when I changed the solenoids. The solenoids eventually failed putting my vehicle into a limp mode.

I highly recommend changing the solenoids when any high mileage vehicle has a transmission service, if they have not been changed previously. They are messy but straight forward to change. The cost of the solenoid kit was about the same as the oil and filter for a service which you need to replace for a solenoid change anyway.

Hmm. Thanks for this. I'll add it to my list.

 

[Carson G]

Could you explain why? Genuinely curious. What occurs when the adaptations are reset?

I’m no expert when it comes to these specific transmissions but from the reading I did when I was researching about it for my own truck most people said it generally makes it worse. I personally haven’t figured out why yet. I also wouldn’t replace just the solenoids in a vehicles I was gonna keep a while, there’s several other rubber components that break down in the valve body that cause it to shift funny. Solenoids are just the first symptom. My personal opinion is to rebuild the whole mechatronic assembly if your gonna keep it for the long haul. If your not gonna keep it that long you could probably just swap the solenoids and it might work better for awhile.

 

[RR876]

I forgot to mention the rubber tubes and seals when removing the mechatronic unit. In fact, it’s one of these rubber tubes that leads to the down shift thunk. I did not take the mechatronic unit apart and only replaced the valves and seals plus oil and filter. The transmission is shifting very nicely now.

There are many forum posts on the topic and so I won’t repeat them here except for one point. When I did the mechatronic remove and replacement, much more oil came out than with a standard oil drain and filter replacement. I refilled with 8 litres and is still a little low. I suggest having plenty of oil on hand, otherwise your vehicle may be stuck waiting for more oil.

 

[03Evan]

If you have a gap tool, there is a software update to address the “ca stop” bump.

I did a full service (new seals between the mechatronic and transmission body, cleaned solenoids, new fluid and new filter) at 295k miles. Re-adapted and drove VERY carefully. Runs perfect now.


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