Confirmed ZF 8HP75 "Failure" due to Whining Noise

[voda.dubz]

Hey everyone, just wanted to document my experience for the group in case anyone else is chasing a mystery noise.

The Specs: 2022 Gladiator Rubicon EcoDiesel. Currently at 36k miles. I purchased it used from a dealer just 1 month ago with 35k miles.

The Symptom: Distinct metallic "whining" noise. It was RPM-dependent and sounded like a supercharger whine or a dry bearing. At first, I thought it was just part of the characteristic EcoDiesel noises... but after a few hundred miles, I started investigating and became concerned.

The Key Diagnostic Factor: The noise persisted in Park and Neutral. This ruled out differentials and axles.

The Process: I took it to the dealer to get checked. They initially diagnosed it as an idler pulley and replaced it, but the noise remained identical. Since the noise happened while stationary (Park/Neutral), we narrowed it down to the transmission—specifically the Oil Pump inside the ZF 8HP75, as it spins with the engine even in Park.

The Verdict: The dealer agreed the sound is coming from the transmission and advised they are submitting a claim for "internal transmission failure." Since these are "sealed for life" units (as they advised), they don’t perform internal repairs or even service the fluid/filter.

The Outcome: Full transmission replacement recommended under Powertrain Warranty (currently pending final approval). The bad news? I’m looking at a 1-2 month wait for a new 8HP75 assembly to arrive, with the Gladiator stuck at the dealer all that time.

I did a lot of research prior to buying an EcoDiesel Gladiator. I even read about a "whining noise" issue affecting the 8HP75s before buying... and sure enough, it got me.

That said, I am loving the EcoDiesel platform so far. My previous Jeeps were two (3.6L) JKURs... and the JL/JT platform is definitely a huge upgrade. I also have to mention that the dealer providing service has been very diligent and supportive. I just hope this gets sorted out and that I get a "good" 8HP75 this time.

Note on Fluid Changes: In the process of deciding whether to leave the Jeep at the dealer for a replacement or try to fix it myself, [this thread] (https://www.jeepgladiatorforum.com/...transmission-warranty-for-using-amsoil.60204/) helped me make the right decision (not venturing to change the ATF fluid/filter hoping the noise would be eliminated or "improved").


If you hear a whine that follows your RPMs in Park... get it checked ASAP.

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[ShadowsPapa]

specifically the Oil Pump inside the ZF 8HP75, as it spins with the engine even in Park.

They all do in all automatics........... driven by the torque converter in most cases.
These have a 2nd electric pump to maintain pressures and hold the thing in drive when the engine is off due to ESS, so there's that, too.

You can service them yourself - just use the recommended fluid if you ever want to consider dealer or warranty things.
As far as repairs - forget it. Yeah, it can be done, but dealerships aren't trained on them and the hourly rate would be killer - plus, then Jeep wouldn't cover it if it failed again, the dealership would have to.
You'll get a reman transmission with a good warranty and it's likely to be even better than the original.

 

[Hookr26]

Diesel Transmission exploding at 35k. Had that happen with my 2021 JLU Rubicon at 35k. One day working fine, next day some kind of whine coming from under the jeep. Got it home. Next day I headed to daily chores, turned around after a couple of clunks accompanied by a motion surge after the whine began again. Drove it strait to dealership. Took a few days and they said they thought it would need repair, Ya THink? A few days later they said Jeep told them to do a few other tests. So after second week Jeep decided it needed a replacement transmission. Took 2 months, good thing I had plenty of other vehicles to keep from needing a loaner. Sure Glad they followed thru. Nothing but good things to say about the dealer. This vehicle was about our 7th/8th vehicle we have purchased from them. Now at 70k, 35 past the last time it failed and no new problems since. Hope it stays that way.

Did do a little learning in the process and despite the "no need to do service" had some folks I've trusted for years suggest the oil/filter change at this transmissions 70-80k for extended longevity. I truly hope my 3.0 eco diesel makes the 150-200k. Was doing 8-9k oil changes, with every other O/C fuel filer, with latest info now working for oil/fuel swaps @ 5k-ish. Done all other listed services as well.

I have to admit, I like the platform enough I just bought a 2021 JT Rubi 3.0D with 26k miles about 6 months ago. I started the 5k-ish oil changes and adding the Archoil 6500 additive. One of my kids is borrowing my JLU at the moment but want to add the Archoil to its daily use as well.

 

[voda.dubz]

Did do a little learning in the process and despite the "no need to do service" had some folks I've trusted for years suggest the oil/filter change at this transmissions 70-80k for extended longevity. I truly hope my 3.0 eco diesel makes the 150-200k. Was doing 8-9k oil changes, with every other O/C fuel filer, with latest info now working for oil/fuel swaps @ 5k-ish. Done all other listed services as well.

Yessir! That was exactly my plan. I was all set to do the pan/filter drop using Lifeguard 8 at 40k miles, but this failure beat me to it.

I decided not to tinker with it to avoid giving them any ammo to deny the claim. Better to let the warranty handle the heavy lifting. Once the new unit is in, I’m definitely sticking to a 40k-mile (or less) interval.

Regarding that thread I linked—the theory about leftover coolant contamination from the manufacturing process is definitely a possibility. Before taking it in, I actually checked the fill port just to rule out low fluid level as the cause of the noise. The level was spot on, but the fluid color was concerning... it was very dark for just 36k miles.

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