Brake Fluid and Differential Gear Oil Change Interval

[SHUGGAR]

2024 Performance 6MT, Coming up on 20,000 mile service. The owners manual says replace the brake fluid and differential gear oil. This seems early to me. Mainly highway miles @ 60-80 MPH in Las Vegas NV. Not aggressive at all. I have had my fair share of stalls getting back into the manual mode. Will the warranty be voided if this service is not done on the recommended schedule? Looking forward to your feedback.

 

[rocksandblues]

why wouldn't you follow the manufacturer intervals?
Trying to save a couple hundred dollars on a 50k purchase

 

[Thefunk]

2024 Performance 6MT, Coming up on 20,000 mile service. The owners manual says replace the brake fluid and differential gear oil. This seems early to me. Mainly highway miles @ 60-80 MPH in Las Vegas NV. Not aggressive at all. I have had my fair share of stalls getting back into the manual mode. Will the warranty be voided if this service is not done on the recommended schedule? Looking forward to your feedback.

It is illegal in the United States for any company to void warranties. All they can do is deny warranty service if they can prove modification caused the issue.

 

[vheiskell]

2024 Performance 6MT, Coming up on 20,000 mile service. The owners manual says replace the brake fluid and differential gear oil. This seems early to me. Mainly highway miles @ 60-80 MPH in Las Vegas NV. Not aggressive at all. I have had my fair share of stalls getting back into the manual mode. Will the warranty be voided if this service is not done on the recommended schedule? Looking forward to your feedback.

Moisture getting into brake fluid is what makes it get gunky. Living in LV I venture to say you could go a lifetime and not need to change it. However I live in the panhandle of Texas not much difference and after 5 years my Brake Fluid needed flushing. Get a moisture checker from about anywhere and check it. It has Red, Yellow, Green lights on it for moisture content.

 

[thesilverbullet]

for street use, i wouldn't worry about the brake fluid. I have 200K+ miles on my taco and never changed the brake fluid or add any. keep that system sealed as long as you can.

However, I would change the engine, tranny and diffy fluids early and often.

 

[Meg_Z]

I think it’s foolish to not do what the manufacturer recommends. I’m not talking about the add on BS the dealer tries to throw in while getting a service done. I either allow the dealer to do it or do it myself. I’m coming up on 15K and will get the dif, trans and brake fluid changed for my piece of mind.

 

[Thefunk]

I heard something interesting about these Jatco auto trans are modified Mercedes transmissions and that you should not change the fluid on them because the fluid becomes "part" of the transmission over time. So changing the fluid frequently in the car's lifetime may adverse affects.

 

[RobotAZ]

I heard something interesting about these Jatco auto trans are modified Mercedes transmissions and that you should not change the fluid on them because the fluid becomes "part" of the transmission over time. So changing the fluid frequently in the car's lifetime may adverse affects.

Has nothing to do with Mercedes or Jatco. Basically this is advice from meatheads who noticed when they dumped the garbage out of the transmission, changed the fluid, and got leaks or other issues that it’s the fluid’s fault. It’s because the transmission was reduced to working with crap over time and fresh fluid causes problems to the damaged and out of spec machine.

 

[Meg_Z]

Has nothing to do with Mercedes or Jatco. Basically this is advice from meatheads who noticed when they dumped the garbage out of the transmission, changed the fluid, and got leaks or other issues that it’s the fluid’s fault. It’s because the transmission was reduced to working with crap over time and fresh fluid causes problems to the damaged and out of spec machine.

In other words folks who thought they knew better than the engineers and ignored recommended fluid change intervals, because that’s the way they always did it.

 

[Thefunk]

In other words folks who thought they knew better than the engineers and ignored recommended fluid change intervals, because that’s the way they always did it.

Sounds about right. Probably the same reason why key fobs aren't encrypted and the infotainment systems usually suck. There's a huge disconnect between engineers, mechanics, and IT people.

 

[Garage King MI]

The BMW track crowd has been swearing by Red Line fluids for the past ~15 years.

Currently, and unfortunately, Red Line does not appear to offer directly-compatible Transmission or Differential fluids for the Z .

I've reached out to Red Line for information on any current "closely-compatible" or "in-development" fluids that will work for our Z's.

Based on feedback from the Motor City BMW Club, it is possible Red Line Transmission Fluid could mitigate/reduce shifting "notchiness" anomalies.

 

[Thefunk]

Here's an informative video about the Jatco 9sp auto.


I saw another RZ34 specific video about how to replace the fluid. Seems a little complicated to me at least but doable.

 

[Thefunk]

The BMW track crowd has been swearing by Red Line fluids for the past ~15 years.

Currently, and unfortunately, Red Line does not appear to offer directly-compatible Transmission or Differential fluids for the Z .

I've reached out to Red Line for information on any current "closely-compatible" or "in-development" fluids that will work for our Z's.

Based on feedback from the Motor City BMW Club, it is possible Red Line Transmission Fluid could mitigate/reduce shifting "notchiness" anomalies.

I wish it was that easy to fix the .5sec delay between the paddle and actual shift.

 

[thesilverbullet]

2024 Performance 6MT, Coming up on 20,000 mile service. The owners manual says replace the brake fluid and differential gear oil. This seems early to me. Mainly highway miles @ 60-80 MPH in Las Vegas NV. Not aggressive at all. I have had my fair share of stalls getting back into the manual mode. Will the warranty be voided if this service is not done on the recommended schedule? Looking forward to your feedback.

The brake fluid service interval (20k or 2 years) is mainly because of the dot 4 fluid and to maintain a higher than normal performance. Dot 4 absorbs water much faster than dot 3. But since you are in a dry climate along with mild manner driving, water might not an issue for you.

I wonder how many ‘24 Zs have a mid year ‘23 born on date that were purchased in ‘25 with little or no miles but are 2yrs old.

is any one looking at switching to a dot 5.1 fluid with a one year service interval?

for the record i just changed my engine oil and filter at 1k.