Lifetime diff and gearbox oil

[Marlon]

My Indy tells me that the Diff and gearbox oils are BMW lifetime oils and therefore don't need changing.
My Zed is a 2008 3.0si. This was news to me cos I've heard lots of advice on the forum about changing those oils at inspection 2?

 

[buzyg]

Strange thing to say. How long is life on a E85 Z4. 200,000 miles ish. For sure they get changed at Ins II on the ///M. Not sure on the 3.0i, but can't do any harm. Will make the gear change feel better.

 

[mr wilks]

10yrs or over 75k & its something i like to have done & favour Millers
Just last week had the gearbox oil changed on E89 but my Indy said no drain on diff so that had to stay in

 

[highway1]

There is no drain on the diff so you have to have the oil sucked out- surprised your indy didn't just do that??

 

[SonnyA85]

My Indy tells me that the Diff and gearbox oils are BMW lifetime oils and therefore don't need changing.
My Zed is a 2008 3.0si. This was news to me cos lots I've heard lots of advice on the forum about changing those oils at inspection 2?

BMW don't care if these car fails after their warranty runs out. Basically their real customers are those that buy new cars or cars a few years old through their approved used scheme. By the time these fluids deteriorate BMW's customers no longer own them and have bought another new or nearly new car. Basically if you want the car to last change them, if you don't leave as is and let the next owner deal with it.

I did extensive research and the company that actually manufacturers the gearboxes states the below which I sent by email to dealer who refused to change the oils until I sent this in.

RE: Recent Phone call from your service centre. They advised that the
oils are "lifetime" and never need changed. As below that means 80,000
to 120,000 km or 8 years. They car in question is 13 years old and
done 90,000 miles.

Every owners forum I've looked at suggest changes every 4 years or
30,000 miles whichever is soonest especially on the auto transmission.

Might be worth getting your technicians to read through the following.
Especially the second link about newer transmissions that BMW's use
from 2013 onward. Basically there is no such thing as a lifetime
fluid. Everything eventually starts to break down and need replacing.

"My basic maintenance schedule for the Zed is:

Engine Oil/filter: 7000 to 7500 miles or once a year. High revving
engines need better oil protection.
Automatic Transmission fluid/filter: 30,000 miles or every four years.
Especially the Automatic Transmission.......
Manual Transmission: Best case 30,000, worst case 50,000 miles
Differential fluid: Best case 30,000, worst case 50,000 miles

Drain and flush the coolant every two years. Coolant does not wear
out, but the corrosion resistant properties fade.
Flush the break fluid every two years. Its hydroscopic - absorbs
water. Reduces temperature that fluid will boil.
Change Spark Plugs every 50,000 miles. Very cheap insurance.
Replace upstream (front) O2 sensors every 65,000 miles. The design
life of most O2 sensors is 60,000 miles.
Clean my Air Filter every three to six months.."

Taken from the below link

http://www.z4-forum.com/forum/viewtopic.php?t=11525


http://www.bimmerfest.com/forums/showthread.php?t=847757

Below is taken from the above link.

Hi BMW Owners,

This transmission fluid conundrum applies to all BMW series. You and I
have read way too many threads arguing whether the "Lifetime"
automatic transmission fluid (ATF) needs to be changed or not. As a
professional mechanical engineer, I decided to look for a scientific
answer straight from the source: ZF company, the manufacturer of BMW
transmissions. As of 2013 nearly all BMWs (1-7 series) use the ZF-8HP
transmission. The following case study is for my vehicle F30 335i
which uses the ZF-8HP45 model [Ref. 1], but the info applies to any
other series as well. References are provided at the end of this
writing if you want to confirm them yourself.

A data sheet for 8HP45 as published by ZF specifies the transmission
oil as "lifetime oil fill" [Ref. 2]. Other models such as 8HP70 for
the 7-series and X5 also repeat the same statement. Being a true
scientific researcher, I was not satisfied with this statement because
everything in this world will degrade and fail. The question is not
if, but when. So I went on to research more into the ZF lubrication
fluids and discovered that they manufacture variants of transmission
fluids. In the case of automatic transmissions for cars including the
8HP models, the fluid is part no. TE-ML11 [Ref. 3]. A straight copy
and paste from the datasheet regarding maintenance states:

"... automatic transmissions are filled maintenance-free with
specially developed partially synthetic ATF oils. Maintenance-free
fills are intended for normal operating conditions. Especially driving
at very high operating temperatures can result in accelerated aging or
increased wear of ATF oils. It is recommended, in the event of severe
operating conditions, such as:
- frequent highway driving in top speed range,
- offensive, sporty driving style,
- frequent trailer operation,
being above average, oil purification (oil change) on automatic
transmissions is recommended between 80,000 km and 120,000 km, or 8
years, depending on the load."

Based on the ZF's data sheet, it is clear to conclude our discussion
with the following points:
1) The ZF ATF was designed to last beyond 120,000 km or 8 years if you
drive under normal operating conditions.
2) Changing the ATF is allowed and will not result in damaging the
transmission unit as long as you use the correct ZF fluid.
3) You don't have to be ripped off by buying the ATF from a BMW
stealership, the ATF for 8HP models is ZF Lifeguard Fluid 8 (ZF No.
S671 090 312) and it's available online.

You can search for the specific model of your transmission online and
find the required fluid from [Ref. 3]. I attached the PDF for your
convenience. I hope this post resolved our doubts and misconceptions.

References:
[1] F30 Technical Data,

[2] ZF 8-speed Automatic Transmission Technical Information, PDF format,

[3] ZF List of Lubricants, TE-ML_11, PDF format


I hope this helps with any queries as to why I requested the
"lifetime" fluids to be changed.

 

[Scooba_Steve]

It's not. Change it, at 70k my box oil was not pretty, diff not so bad but still worth doing for the fifty-odd it cost.

Some diffs have drains, some don't. Either way, add it to the to-do list.

Unless you want more "I told you so"

 

[Marlon]

Thanks everyone - my zed is at 45k so will look at this again at 70/80k

 

[markeg]

Changed my gearbox/diff oil again last week, after 50k since the last change. I initially changed it when I first got the car in 2009 as I didn't know how it had been treated.

 

[maxman]

Changed the oil for diff and gearbox at 50k.Gearchange seemed smoother.

 

[SonnyA85]

Thanks everyone - my zed is at 45k so will look at this again at 70/80k

80,000 km and 120,000 km, or 8
years, depending on the load

yours is 8 years old. so I would recommend getting it done.

that's from the official manufacturer of the gearboxes. so i would get it done.

 

[Scooba_Steve]

Thanks everyone - my zed is at 45k so will look at this again at 70/80k

It's been in there for 8 years so still worth getting done - can't hurt and I certainly noticed a big improvement in shifting once I'd done the box. Mechanical sympathy is good, as is preventative maintenance

 

[d3matt]

Mine is 13 years old and 110,000 miles and I bet the oils have never been changed. Just ordered a full set of Castrol oils, including engine oil and a cheap suction pump of eBay. Cost £141. Hope to give the car new blood next weekend.