2018 G80 Sport Transmission bumps in middle of gears

[Gearhead2018]

Feeling a bump in the middle of gears 2-5 during all types of acceleration. New plugs/COP’s and no CEL. Dropped it off at the dealer they drove it twice and labeled it early stages transmission failure after 2 days, due to hard shifting . They can’t tell me what they think is failing and it shifts just fine buts feels like multiple miss in the middle of the gears. This is under dry mild acceleration or hard acceleration. Anything to try without throwing a $5k transmission in?

 

[TinsleyC]

I assume you bought it used, otherwise it would be covered by the 10 year drive train warranty. I'm sure it was manufactured before Aug 2018.

 

[Gearhead2018]

I assume you bought it used, otherwise it would be covered by the 10 year drive train warranty. I'm sure it was manufactured before Aug 2018.

Yes, not covered under any warranty since I’m the 2nd owner.

 

[5.0KDM]

Did you try the shift solenoid tsb?

The mystery about transmission hard shift is finally revealed (TSB for HARSH 2~3, 3~4 OR 4~5 UPSHIFT)

Not sure if this was addressed in another post and if yes, accept my apologies. The mystery about transmission hard shift is finally revealed. Hyundai issued a TSB for HARSH 2~3, 3~4 OR 4~5 UPSHIFT back in November 2021. The culprits are two solenoids which Hyundai upgraded and they need to...

genesisowners.com

 

[Gearhead2018]

The shifts are fine it is bumping during the 1300-2300 rom pull in the middle of these gears. It feels like a bad coil and the engine missing but I have new COPs and plugs (gapped at 0.028”). On the Highway it is fine because it is in higher gears.

 

[bubbaG80Sport]

@Gearhead2018
Is your "bumping" a shudder/slip feeling?
Is your 2018 g80 sport AWD/HTRAC?

If so, consider change the AWD transfer case fluid.

My 2018 G80 Sport AWD 3.3T was experiencing a slip/shudder accelerating from ~20->50mph. Took to dealer and they diagnosed a bad torque converter. Entire tranny replaced under warranty but did not completely eliminate the issue. Doing research led me to change TC fluid. Dealer will likely not do this. Genesis TSB/service manual indicates replacing TC not fluid if there is an issue. . I changed the TC fluid a second time about 5K miles later.

There is an extensive thread "Long term reliability of HTRAC AWD transfer case due to inability to change the transfer case fluid?" on this topic. My post on the TC fluid is here.

 

[KCArt]

Feeling a bump in the middle of gears 2-5 during all types of acceleration. New plugs/COP’s and no CEL. Dropped it off at the dealer they drove it twice and labeled it early stages transmission failure after 2 days, due to hard shifting . They can’t tell me what they think is failing and it shifts just fine buts feels like multiple miss in the middle of the gears. This is under dry mild acceleration or hard acceleration. Anything to try without throwing a $5k transmission in?

I've been trying to find info on the same problem. I found this service bulletin, which was issued in 2021 and only covers models up to 2016.

 

[KCArt]

That bulletin came from https://static.nhtsa.gov/odi/tsbs/2021/MC-10204249-0001.pdf

Like Click and Clack used to say, when told they all do that: "Then they all need to be fixed; let's start with this one."

 

[Gearhead2018]

I've been trying to find info on the same problem. I found this service bulletin, which was issued in 2021 and only covers models up to 2016.

I’ve seen this TSB and other discussion about the shift solenoid. I don’t think any of those are relating to the issue I’m having… Shifts aren’t hard or jerky and it definitely is in the middle of the gears. I’ve ordered fluid for transfer case…. Having a clutch basket in there seems the most logical point of failure right now. Thinking it’s releasing and then relocking the front wheels, hoping there just aren’t damaged friction plates/spacers/spring washers in there.

 

[Gearhead2018]

@Gearhead2018
Is your "bumping" a shudder/slip feeling?
Is your 2018 g80 sport AWD/HTRAC?

If so, consider change the AWD transfer case fluid.

My 2018 G80 Sport AWD 3.3T was experiencing a slip/shudder accelerating from ~20->50mph. Took to dealer and they diagnosed a bad torque converter. Entire tranny replaced under warranty but did not completely eliminate the issue. Doing research led me to change TC fluid. Dealer will likely not do this. Genesis TSB/service manual indicates replacing TC not fluid if there is an issue. . I changed the TC fluid a second time about 5K miles later.

There is an extensive thread "Long term reliability of HTRAC AWD transfer case due to inability to change the transfer case fluid?" on this topic. My post on the TC fluid is here.

So I completed my 1st TC fluid exchange and my issue has disappeared! I purchased a 100ml syringe and the Triax TC Fluid off Amazon. I pulled 400-450ml out and the fluid was very dark but didn’t have any burnt odor. Pushed the new TC fluid in and noticed improvement on my 1st drive. I’m going to give it a few weeks and try and get another ~400ml out. With the multidisc clutch in the unit I’m not sure why they wouldn’t recommend changing the fluid more often? Thanks for the recommendation! I’m kicking myself for not trying it sooner.

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