Transmission taking too long to shift

[Longtrail]

This seems like a new behavior today although I've had my suspicions about the transmission for a while, I'm noticing the engine revs are a little higher than I'd like and the transmission is taking longer than I'd expect to shift to the next higher gear. For example, while in second gear the engine is at 1,500 to 2,000rpm range and it seems to hold this too long before shifting to third gear... I'm seeing this across all gears. Just passed 100K miles; 2012, V8; six speed transmission.

Any suggestions?

 

[itsaguything]

That’s funny…. I interpret gear changes at 1500 - 2000 rpm as missing the power band and too early.

Horsepower and Torque curve for 2016 Land Rover LR4 SCV6 (aut. 8) offered until December 2016 for North America

Engine horsepower and torque curve for Land Rover LR4 SCV6 (aut. 8) in 2016, the model with 5-door sport-utility wagon body and V-6 2995 cm3 / 182.9 cui, 253.5 kW / 345 PS / 340 hp (SAE net) offered until December 2016 for North America .

www.automobile-catalog.com

What RPM Should You Shift: Optimal Gear Changing for Enhanced Performance - Ran When Parked - Car, Vehicle & Truck Guides and Repair Journals.

When we talk about driving a vehicle with a manual transmission, knowing when to shift gears is crucial for both performance and fuel efficiency. The moment

ranwhenparked.net

But out of interest, I do change my diff, transmission and power transfer fluids every 50,000 miles. There is currently no lag issue.

 

[scapistron]

Clear the transmission adaptions with the GAP tool and see if that helps.

 

[txfromwi]

For a similar issue, a Rover dealership (that I trust) advised me to disconnect the battery for half an hour to allow things to reset.

 

[itsaguything]

Well, that would be contrary to how the TCM works on a jag. (Edit: Just consulted the workshop manual. A software reset IS necessary) A system reset will not affect the TCM. Those adaptations can only be reset with software.

But delayed shifting is one of those indications that something is amiss.
So…. When was the last fluid and filter change? Transmission fluid quality is paramount to good transmission operation.

 

[Jimmy Brooks]

For a similar issue, a Rover dealership (that I trust) advised me to disconnect the battery for half an hour to allow things to reset.

This clears the adaptations.

 

[Longtrail]

That’s funny…. I interpret gear changes at 1500 - 2000 rpm as missing the power band and too early.

Horsepower and Torque curve for 2016 Land Rover LR4 SCV6 (aut. 8) offered until December 2016 for North America

Engine horsepower and torque curve for Land Rover LR4 SCV6 (aut. 8) in 2016, the model with 5-door sport-utility wagon body and V-6 2995 cm3 / 182.9 cui, 253.5 kW / 345 PS / 340 hp (SAE net) offered until December 2016 for North America .

www.automobile-catalog.com

What RPM Should You Shift: Optimal Gear Changing for Enhanced Performance - Ran When Parked - Car, Vehicle & Truck Guides and Repair Journals.

When we talk about driving a vehicle with a manual transmission, knowing when to shift gears is crucial for both performance and fuel efficiency. The moment

ranwhenparked.net

But out of interest, I do change my diff, transmission and power transfer fluids every 50,000 miles. There is currently no lag issue.

Thanks for the input; I bought the car at about 94,000 miles, I don't know the history of the transmission fluid so I've long suspected this may be on the radar. I don't know how to explain what's happening other than my gut is telling me it's not right (I generally have pretty decent instincts with mechanical things)... The important thing is I'm not requesting acceleration; this is on a very neutral throttle, going slowly on country roads, I'm not in a hurry and it just lingers in the gears for too long.

 

[Longtrail]

Well, that would be contrary to how the TCM works on a jag. (Edit: Just consulted the workshop manual. A software reset IS necessary) A system reset will not affect the TCM. Those adaptations can only be reset with software.

But delayed shifting is one of those indications that something is amiss.
So…. When was the last fluid and filter change? Transmission fluid quality is paramount to good transmission operation.

OK, Thanks. I'll get out the GAP tool and take a look. As mentioned above, I suspect the fluid needs changing! I still have the timing chains and crossover pipes to do so I guess I'm looking for a little more time on this job! I've read the other stories and don't relish lying under the LR4 to do this work! Front and Rear diffs have been done along with the transfer case; this is the last big one on the underside.

 

[itsaguything]

Hmmm... maybe.
All the documentation from ZF is clear... DO NOT reset the adaptations until the DTCs are read and dealt with.
And the number one cause of transmission failure is poor quality/ or non compliant fluid.
And only perform the adaptation reset once DTC's are not thrown AND after a many kms driving effort following a fluid change.
The D4 workshop manual states using software. As does the Jag workshop manual. (And Bimmer, for that matter)
And that the ECM and PCM may be reset with a battery disconnect ... but not the TCM. So I humbly defer to others that wish to ignore these very clear instructions.
Incidentally ZF says this for the 6HP:

https://www.rangerovers.net/attachments/lr3-trans-adaption-pdf.106417/

 

[Longtrail]

Hmmm; some more!...

It did throw a transmission fault perhaps a few months back (driving on the highway) but I've not seen that particular code come back (or any others for that matter). If and when I tackle this job I'll only ever buy the correct fluid based on doing some decent research; I know not to cut corners here (or any anywhere with this vehicle!)... So, also, don't do the adaptation until the fluid has been changed and some miles/km's have been accumulated, OK. Will go do some more research.

Can someone confirm that the transmission model is 6HP26? Is it the same as the one in the LR3 in which case this video is somewhat interesting and aligns to a degree with the pdf mentioned in the previous post:

Have others attempted the relearn procedure, it's sort of implied that people just drive after changing the fluid, am I missing something?

Is this the kit that others are using?

https://www.roverparts.com/transmission/kits/ATFCKOME/