2015 3.8rwd 5th gear to 6th gear slippage

[carguy75]

I don’t have a tool myself. Not sure if some of the shops will have it either. Reading thru other threads it seems like I need to ask for a g scanner.

EDIT:
I used the thinkscan tool from a friend's shop and it's not supported (the A/T Reset). I was able to reset some other modules though.

FYI: If you guys ever get the vehicle to spin while on the lift, it may have an effect on the front left/right modules which then has an effect on the electronic stability control (my car was a little wonky in terms of suspension prior to the reset).

Sounds about right. I ended buying a Xtool D8 scan tool to cover all my cars that need high end programming or functions. Most newer cars need a bi-direction scan tool like a G-scanner or Xtool D8 to perform functions like transmission adaption relearn.

 

[Husam]

What aftermarket fluid did you use?

I am starting to think that the filling process for aftermarket fluid may need to be adjusted to account for a different amount of fluid expansion when the fluid is warm compared to the OEM fluid.

I used a aftermarket fluid that is formulated like the stock fluid so I did not have any issues, but universal fluids may be formulated different enough that the fluid may need to be filled at a different operating temperature for a proper fill up. Just speculation.

I used CERMA ATF, about a gallon and added Hot Shot's Secert Shift Restore additives.

It is said that CERMA ATF takes about 1000 miles for it to work! Not sure though.

I made sure that the Level is accurate while adding ATF and checked it at 60 degrees Celsius.

Expansion properties of the ATF may be a factor like you said.

 

[carguy75]

I used CERMA ATF, about a gallon and added Hot Shot's Secert Shift Restore additives.

It is said that CERMA ATF takes about 1000 miles for it to work! Not sure though.

I made sure that the Level is accurate while adding ATF and checked it at 60 degrees Celsius.

Expansion properties of the ATF may be a factor like you said.

Interesting choice of transmission fluid you used. The website claims Cerma transmission fluid works in all transmissions except CVT and SVT units. Red flag. No one transmission fluid works well in "every" automatic transmission. The Hyundai 8 speed seems like it is very sensitive to what transmission fluid is used in it.

I would drain the Cerma fluid and use OEM or a specific OEM equivalent transmission fluid. Just my take on the issue.

 

[Husam]

Interesting choice of transmission fluid you used. The website claims Cerma transmission fluid works in all transmissions except CVT and SVT units. Red flag. No one transmission fluid works well in "every" automatic transmission. The Hyundai 8 speed seems like it is very sensitive to what transmission fluid is used in it.

I would drain the Cerma fluid and use OEM or a specific OEM equivalent transmission fluid. Just my take on the issue.
View attachment 51086

Update with CERMA fluid:

After about 500KMs (not miles) of driving, the transmission shift feel improved more than 60% to 70%. I still get hard shifts, but less and less over time, from 2nd to 3rd on low throttle and from 4th to 5th. However there is an undeniable improvement. No more problems from 5th to 6th.
I've also noticed that the RPM shift points are higher, shifting happens over 1500 or 1700 RPM which makes me believe that the transmission oil pump is/was to blame.

 

[carguy75]

Update with CERMA fluid:

After about 500KMs (not miles) of driving, the transmission shift feel improved more than 60% to 70%. I still get hard shifts, but less and less over time, from 2nd to 3rd on low throttle and from 4th to 5th. However there is an undeniable improvement. No more problems from 5th to 6th.
I've also noticed that the RPM shift points are higher, shifting happens over 1500 or 1700 RPM which makes me believe that the transmission oil pump is/was to blame.

Hard to say really. We could speculate on the cause, but the universal fluid would be my first point of concern for the abnormal transmission performance.

I would try OEM or OEM equivalent transmission fluid before looking into a new transmission pump.

 

[Husam]

Hard to say really. We could speculate on the cause, but the universal fluid would be my first point of concern for the abnormal transmission performance.

I would try OEM or OEM equivalent transmission fluid before looking into a new transmission pump.

I actually did. My initial drain and fills were with OEM ATF and then Amsoil ATF with which the hard shifts persisted. I also did a TCM relearn and reflash, no luck.

 

[carguy75]

I actually did. My initial drain and fills were with OEM ATF and then Amsoil ATF with which the hard shifts persisted. I also did a TCM relearn and reflash, no luck.

It seems like your transmission need the new shift solenoids located in the TSB that is suppose to address hard shifting.

 

[Husam]

It seems like your transmission need the new shift solenoids located in the TSB that is suppose to address hard shifting.
View attachment 51174

Yes and I've done that too.

 

[skipgen]

Hard to say really. We could speculate on the cause, but the universal fluid would be my first point of concern for the abnormal transmission performance.

I would try OEM or OEM equivalent transmission fluid before looking into a new transmission pump.

Mine went back to (mostly) normal smooth function after my drain & refill with new trans pan / filter. I still get the occasional 2nd/3rd flare & botched downshift. My suspicion is that I need another drain & refill and resetting of adaptive values to set it right... Weird thing is that it'll shift normally for a few weeks & "act up" for a few days and then go back to "normal" - Rinse, repeat. Note: I didn't reset adaptive values after the previous service - probably should have.

 

[carguy75]

Mine went back to (mostly) normal smooth function after my drain & refill with new trans pan / filter. I still get the occasional 2nd/3rd flare & botched downshift. My suspicion is that I need another drain & refill and resetting of adaptive values to set it right... Weird thing is that it'll shift normally for a few weeks & "act up" for a few days and then go back to "normal" - Rinse, repeat. Note: I didn't reset adaptive values after the previous service - probably should have.

Like mention above in post#27, you may need to consider the TSB fix.

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[carguy75]

Yes and I've done that too.

Well, you used OEM fluid which did not fix the issue. You actually claim to swapped out the solenoids per the TSB; still no fix. The problem could be mechanical in nature like the pump that you suspect, so I suggest you have a transmission shop inspect your transmission.

 

[skipgen]

Like mention above in post#27, you may need to consider TSB fix.

My shifts were never particularly harsh - more like just a bit "discombobulated" and ill timed. It shifts fine 85% of the time after my fluid drain - much improved from before.

 

[carguy75]

My shifts were never particularly harsh - more like just a bit "discombobulated" and ill timed. It shifts fine 85% of the time after my fluid drain - much improved from before.

It could be that your transmission still has some old fluid in the system. It will take a few more fluid changes to remove all the older fluid out the system. The performance may improve after another drain and fill. The updated shift solenoids could not hurt, but I would not go that route unless I get a trouble code.

 

[skipgen]

It could be that your transmission still has some old fluid in the system. It will take a few more fluid changes to remove all the older fluid out the system. The performance may improve after another drain and fill. The updated shift solenoids could not hurt, but I would not go that route unless I get a trouble code.

That was my thought.... some clots of old stuff still circulating. My guys said about 6 quarts came out - so, I guess the remaining 40 - 50% is "old" & doesn't have proper shear characteristics.

 

[koovoodoo]

Updated in regards to my situation:

I changed the oil with Ravenol SP IV-RR and it's still the same problem. Even checked the ohms of the solenoid, spray them all with mass flow cleaner while intermittently activating the solenoid with a 9v battery to get at the crevices. Ultimately same result and not much difference in terms of driving thru other gears.
FYI refill took around 8 liters for me haha a lot more than what other people have been posting about refill.

Tomorrow (crossing fingers) OBD2 tool comes that can help me reset the AT and start the gear learning? We'll see how that turns out.

Thanks to all other posters sharing their info too!!!

 

[carguy75]

Updated in regards to my situation:

I changed the oil with Ravenol SP IV-RR and it's still the same problem. Even checked the ohms of the solenoid, spray them all with mass flow cleaner while intermittently activating the solenoid with a 9v battery to get at the crevices. Ultimately same result and not much difference in terms of driving thru other gears.
FYI refill took around 8 liters for me haha a lot more than what other people have been posting about refill.

Tomorrow (crossing fingers) OBD2 tool comes that can help me reset the AT and start the gear learning? We'll see how that turns out.

Thanks to all other posters sharing their info too!!!

No problem. Seems like you will do all that you could to fix the problem without having an transmission shop crack the unit open.

I am now starting to see(or hear about) more and more high mileage(near or over 100k miles) Hyundai 8 speed transmissions having performance problems; so it may be a mechanical issue with these units due to running the transmission fluid too long before a change or maybe some design flaw that appears with age.

What brand and model of scan tool did you buy?

 

[koovoodoo]

No problem. Seems like you will do all that you could to fix the problem without having an transmission shop crack the unit open.

I am now starting to see(or hear about) more and more high mileage(near or over 100k miles) Hyundai 8 speed transmissions having performance problems; so it may be a mechanical issue with these units due to running the transmission fluid too long before a change or maybe some design flaw that appears with age.

What brand and model of scan tool did you buy?

I bought the Thingdiag. I messaged the company and they said that the function was supported. It never hurts to try things is my Moto. Good learning experience.

 

[Husam]

I bought the Thingdiag. I messaged the company and they said that the function was supported. It never hurts to try things is my Moto. Good learning experience.

Before you go towards AT overhaul, do the AT reset and drive it for about 100 miles. If the issue persists then remove 1 quart of ATF and add 1 quart of Hotshots Shift Restore additive.

 

[carguy75]

I bought the Thingdiag. I messaged the company and they said that the function was supported. It never hurts to try things is my Moto. Good learning experience.

If you meant Thinkdiag(or Thinkdiag2) it seems to be a good scan tool for the price that appears to include transmission adaption learning for some cars. Hopefully it work for Hyundai models. Post some pics of it working on your Genesis please

 

[Husam]

If you meant Thinkdiag(or Thinkdiag2) it seems to be a good scan tool for the price that appears to include transmission adaption learning for some cars. Hopefully it work for Hyundai models. Post some pics of it working on your Genesis please

It works and it does AT reset for Genesis, I have the same tool.