[Noobtber]

Hello all,

With the weather clearing up, I've finally had the chance to do some spirited driving in the canyons. I've noticed that as the car gets used more, a noise starts to come from the engine/transmission that sounds exactly like a straight cut gearbox, a gear whine that increases and decreases with vehicle speed.
I'm wondering if anyone else has heard this.

Unfortunately, I don't have a video. I'll try to get one next time there's a dry day to stretch my legs.

My car is an ActiveHybrid 3. N55/GA8HP45Z 8AT. I know that the trans differs from the majority of users on here, but any data points on a noise like this would be nice.

-Justin

[Boostedphil698]

Originally Posted by Noobtber

Hello all,

With the weather clearing up, I've finally had the chance to do some spirited driving in the canyons. I've noticed that as the car gets used more, a noise starts to come from the engine/transmission that sounds exactly like a straight cut gearbox, a gear whine that increases and decreases with vehicle speed.
I'm wondering if anyone else has heard this.

Unfortunately, I don't have a video. I'll try to get one next time there's a dry day to stretch my legs.

My car is an ActiveHybrid 3. N55/GA8HP45Z 8AT. I know that the trans differs from the majority of users on here, but any data points on a noise like this would be nice.

-Justin

If its in the forward gears thats a major problem. reverse typically whines because it is straight cut.

[Noobtber]

Originally Posted by Boostedphil698

If its in the forward gears thats a major problem. reverse typically whines because it is straight cut.

Good to know. I'll need to take it to the dealership. I just had the electric oil pump replaced in the trans a few months ago due to a bad seal. Hopefully this isn't a result of that.

[Boostedphil698]

Originally Posted by Noobtber

Good to know. I'll need to take it to the dealership. I just had the electric oil pump replaced in the trans a few months ago due to a bad seal. Hopefully this isn't a result of that.

Probably need a new trans.

[Noobtber]

Originally Posted by Boostedphil698

Probably need a new trans.

Good news: The dealer thinks the noise is simply the electric motor operating at temperature. I managed to capture some of the noise in this YouTube video.


It's worth noting that my BMW dealership doesn't exactly support many ActiveHybrid vehicles. This is the only 3 that they've ever seen. Given that I'm noticing exactly zero performance loss and no warning lights, I'm inclined to let it go. Still, I'll keep the video up just in case someone else has this issue in the future.

-Justin

EDIT: It's worth noting that other ActiveHybrid 3 owners on the Facebook group don't have this noise.

[thejeremyman9]

I'll just note that other people have reported a whine after doing a pan+fluid on the 8AT that was due to low fluid. If it was just serviced and fluid was changed/lost, i would confirm its fully filled.

[Noobtber]

Originally Posted by thejeremyman9

I'll just note that other people have reported a whine after doing a pan+fluid on the 8AT that was due to low fluid. If it was just serviced and fluid was changed/lost, i would confirm its fully filled.

Thanks for the information. I'll have to see if I can get it flushed and refilled to spec.

[njdangelo]

Here is a video of my transmission from almost a a year ago when I was worrried about a similar noise. I've been told its normal as well. I have tracked the car HARD since and had zero issues. I am also on XHP stage 3 transmission tune and BM3 stage 2 and, knock on wood, everything is functioning optimally

[thejeremyman9]

Originally Posted by Noobtber

Thanks for the information. I'll have to see if I can get it flushed and refilled to spec.

To clarify, its not a flush. Its pan+fluid refill, since the filter is in the pan.

[Eschmacher]

I also have a whine in certain gears. Fluid change didn't make any difference. I'm just not going to worry about it.

[Slick_FThirty]

The 8AT is a solid transmission. I'd point to many other possible issues before arriving at the ZF8HP.

Check your fluid level. Consider changing it again.

If the transmission was going bad or is already bad, typically there are many other signs that would occur and not just a noise. You would be complaining about a lot of problems, held gears, jerky shifting, codes etc.

Sometimes cars have their characteristics that make it yours. Meaning that something may have happened but it can still continue on for a long time.

[Noobtber]

Originally Posted by Slick_FThirty

The 8AT is a solid transmission. I'd point to many other possible issues before arriving at the ZF8HP.

Check your fluid level. Consider changing it again.

If the transmission was going bad or is already bad, typically there are many other signs that would occur and not just a noise. You would be complaining about a lot of problems, held gears, jerky shifting, codes etc.

Sometimes cars have their characteristics that make it yours. Meaning that something may have happened but it can still continue on for a long time.

Makes sense. There's a reason ZF is in everything. Only difference is that I don't have the 8HP, I have the GA8HP45Z in the activehybrid, which iirc is much rarer and less tested.

[Noobtber]

Hey all,

A quick update. I brought the vehicle to the dealer, who said that there's no situation where the transmission should ever be opened in its lifetime/the fluid should never be changed. They flat-out refused to work on the car because the sound only comes out on medium-hard driving. Guess I need to go independent.

Their comments about the lifetime fluid concern me. Does anyone know where I can find the spec sheet for ZF transmissions? I want to verify their claims.

-Justin

[thejeremyman9]

Originally Posted by Noobtber

Hey all,

A quick update. I brought the vehicle to the dealer, who said that there's no situation where the transmission should ever be opened in its lifetime/the fluid should never be changed. They flat-out refused to work on the car because the sound only comes out on medium-hard driving. Guess I need to go independent.

Their comments about the lifetime fluid concern me. Does anyone know where I can find the spec sheet for ZF transmissions? I want to verify their claims.

-Justin

The latest guidance from ZF is attached and this topic is beaten to death all over the forums, just search. Most people who choose to do it, change the pan+fluid around 62k miles based on the previous 100k km guidance. New gudiance is 150k km, of course YMMV depending on driving habits. There's also the other side of the coin with people over 150k MILES on original fluid, never changed, with no issues.

[auburnf30x]

Yup, dealer is going to tell you it's lifetime...as well the independent shops that are sipping on the same Kool-Aid. Technically, the BMW dealer is right...the fluid absolutely will be just fine throughout the lifetime of the 50k mile warranty.

ZF recommends 50-60k for regular service, FCP Euro takes it a step further and recommends every 40k miles with anything more than mundane daily use. I tow a bit, so I recently did mine at just under 40k miles.



While the sight would say otherwise, the trans fluid still had some life left. However, the idea behind fluid changes is to change it while it still is good. Once it's not, you start damaging things. However, even at under 40k miles, changing the fluid & filter resulted in a fairly significant improvement. I was surprised.

If you like canyon carving often, I'd shorten your interval to 40k also. Call around to various independent shops until you find one that doesn't use the word lifetime throughout the phone call.

[Phoenix704]

In addition to mileage, time and operating environment also will play a role into fluid degradation. I changed my car's flud at 30k (it was leaking), but the car was also 6 years old. That's 6 years of baking in 100 degree heat in the carolina summers. Its so inexpensive compared to the cost of damage repair, better sooner than sorry.

[Noobtber]

All,

Thanks a ton for you help. This car is just hitting 60k miles, so I'll definitely work to find a reliable independent shop.

I appreciate everyone's responses to this. I'll hope to have some updates on the car's condition soon.

-Justin

[thejeremyman9]

Originally Posted by Noobtber

All,

Thanks a ton for you help. This car is just hitting 60k miles, so I'll definitely work to find a reliable independent shop.

I appreciate everyone's responses to this. I'll hope to have some updates on the car's condition soon.

-Justin

If you do it, you can collect a sample and send it to blackstone labs for analysis.

[futurejl]

i also just did the pan+oil and found out the same winning sound. I used slightly less than 4 quarts of the transmission oil out of 7 bottles from the replacement package. Could you please refer me to the direct source and see how it is addressed and how much oil should be filled. Appreciate in advance.

Originally Posted by thejeremyman9

I'll just note that other people have reported a whine after doing a pan+fluid on the 8AT that was due to low fluid. If it was just serviced and fluid was changed/lost, i would confirm its fully filled.

[F30lolz]

Lifetime fill my @$$, however, I shouldn’t talk as my f36 has 208k miles on the original fluid/filter. No shifting issues and shifts the same when I bought it at 57k miles.

[thejeremyman9]

Originally Posted by futurejl

i also just did the pan+oil and found out the same winning sound. I used slightly less than 4 quarts of the transmission oil out of 7 bottles from the replacement package. Could you please refer me to the direct source and see how it is addressed and how much oil should be filled. Appreciate in advance.

You need to follow the ISTA fill procedure. It involves going through all the gears and monitoring the temperature.