[spiderman1982]

At what point is it a good idea to change the transmission and differential fluids? I think BMW recommends 100k, but that seems too long.

[aidant799]

Originally Posted by spiderman1982

At what point is it a good idea to change the transmission and differential fluids? I think BMW recommends 100k, but that seems too long.

I believe ZF recommend 70-80k miles as the first interval. Further intervals are like 100 and 125k. Depending the model. Ref to 8 speed

[admranger]

My plan is to do them all at 60k miles. Rinse and repeat.

[Mosaud1998]

I was going to have them done at 50k miles. I'll probably do the spark plugs at that time my self. At least, that's what I did on my E90

[Msteiner03]

Would anyone possibly know what fluid to use in the front a rear diff besides the OE BMW fluids?

[Mosaud1998]

Originally Posted by Msteiner03

Would anyone possibly know what fluid to use in the front a rear diff besides the OE BMW fluids?

Redline

[Msteiner03]

Specific weight of fluid?

[Mosaud1998]

Originally Posted by msteiner03

specific weight of fluid?

75w85 gl-5 gear oil

[ab1752]

Diff no problem, same with xdrive, but who is going to do the transmission? My dealer is adamant its lifetime and there's no easy way to get it all out. What are other dealers saying when you inquire?

[admranger]

Originally Posted by ab1752

Diff no problem, same with xdrive, but who is going to do the transmission? My dealer is adamant its lifetime and there's no easy way to get it all out. What are other dealers saying when you inquire?

Your dealer is right…the fluid lasts the lifetime of the transmission. If you want the transmission to last longer, change it at around 60k miles.

It’s not that hard to change, especially if you do the filter at the same time. You won’t get all the fluid out as there’s fluid in the torque converter.

Hardest part is to get the tranny up to the right temp for a proper fill. Exhaust is hot right where you’re working if you have to pump in a little more fluid.

I’d find a good independent shop and have them do it if you don’t have a lift. It’s a messy job to drop the pan and change the filter.

[kosmokratur]

I had my dealer do all of the above at about 60K miles, then I sent all the fluids out for analysis.

[adhrp]

Originally Posted by kosmokratur

I had my dealer do all of the above at about 60K miles, then I sent all the fluids out for analysis.

And what were the results?

[G30M]

Originally Posted by ab1752

Diff no problem, same with xdrive, but who is going to do the transmission? My dealer is adamant its lifetime and there's no easy way to get it all out. What are other dealers saying when you inquire?

he's correct. you won't get all fluid out. but that's how it is. you will change about 70-80% of the fluid with each drain and fill.

change it. because he is also correct that it's a lifetime fluid because when the transmission blows up that's the end of the life of the car.

[kosmokratur]

adhrp, all of the fluids came up as being in excellent condition... except the front diff had signs of excessive wear, and they recommended another change and sample "in just 20K miles." I'm a bit worried about it to tell the truth.

[kosmokratur]

I'm also hearing a bit of gear whine at low temperatures. I had a V12 e38 whose transmission whined like crazy when cold (despite fluid changes using the Filtran filter) but it didn't fail in the 120K miles I owned it. Anyway, I am very interested in the Route 66 warranty for this very reason.

[Joe-BMW33]

The transmissions in these cars is one of the many highlights of the car. It is a champ in terms of reliability. I personally would wait until 90k-100k as recommended. You will want to do a drain and refill, not a flush. Then do it again 20k miles later. This is to get all the fluid out and/or make the mix more new than old. The old fluid will stick to the parts on the first drain and refill. Then for the next it will be mixed in pretty good so the second fill with new fluid will achieve more new fluid.

Be careful doing it too soon. Changing the transmission fluid always presents a risk. There is a chance sediment or particles will get into the wrong place and chip a gear or two. All transmissions produce metal shavings over time. They "should" stick to the magnetic pan bottom, but not always.

[srybicki]

I did all around 60k on my X5 about a year ago. She is currently at 95k and running very well. My 530e is around 70k currently and will be getting the same treatment shortly. Well worth it and not very hard or expensive to do it your self. I use all FCPEURO kits.

[adhrp]

Originally Posted by Joe-BMW33

Be careful doing it too soon. Changing the transmission fluid always presents a risk. There is a chance sediment or particles will get into the wrong place and chip a gear or two. All transmissions produce metal shavings over time. They "should" stick to the magnetic pan bottom, but not always.

This is the part that makes me nervous...and then I start thinking why fix it if it aint broke. If the transmission lasts 200k on original fluid, I'd say it has done its duty.

[Joe-BMW33]

Originally Posted by adhrp

This is the part that makes me nervous...and then I start thinking why fix it if it aint broke. If the transmission lasts 200k on original fluid, I'd say it has done its duty.

Yep, for me, changing the fluid is always a dilemma. I went though the same thing on my E39. The E39 had BMW's "Lifetime" transmission. Meaning they recommended never changing the fluid. I had it done at 92k miles though as evidence showed that it was helpful to do, but with risk.

I had two shops that would not do it for me. They were BMW indie shops that were highly regarded and they both said that in the past when they would do it, some cars developed transmission issues right after. They were more "leave well enough alone".

Turner Motosports ended up doing it for me, but their posture was, only if between 90k-100k. Beyond 100k, so fix what's not broken.

[Mosaud1998]

Originally Posted by srybicki

I did all around 60k on my X5 about a year ago. She is currently at 95k and running very well. My 530e is around 70k currently and will be getting the same treatment shortly. Well worth it and not very hard or expensive to do it your self. I use all FCPEURO kits.

If I had a lift, it would be very easy to do. I'm due for an oil change in 3k miles and don't feel like doing it myself

[ezaircon4jc]

Originally Posted by Joe-BMW33

The transmissions in these cars is one of the many highlights of the car. It is a champ in terms of reliability. I personally would wait until 90k-100k as recommended. You will want to do a drain and refill, not a flush. Then do it again 20k miles later. This is to get all the fluid out and/or make the mix more new than old. The old fluid will stick to the parts on the first drain and refill. Then for the next it will be mixed in pretty good so the second fill with new fluid will achieve more new fluid.

Be careful doing it too soon. Changing the transmission fluid always presents a risk. There is a chance sediment or particles will get into the wrong place and chip a gear or two. All transmissions produce metal shavings over time. They "should" stick to the magnetic pan bottom, but not always.

Old wives tale. ZF recommends, IIRC 60K-70K fluid changes. I did my 2012 535i at ~75K and my 2014 535i at 70K. The 2012 was running strong when we traded it in at about 98K miles. I plan on doing our 2019 at about 60K (have ~39K now).

"Lifetime" fluid is lifetime of the trans, which will be significantly shorter without a fluid change. Would you not change the engine oil? Or the brake fluid? How about the coolant?

[Mosaud1998]

Originally Posted by ezaircon4jc

Old wives tale. ZF recommends, IIRC 60K-70K fluid changes. I did my 2012 535i at ~75K and my 2014 535i at 70K. The 2012 was running strong when we traded it in at about 98K miles. I plan on doing our 2019 at about 60K (have ~39K now).

"Lifetime" fluid is lifetime of the trans, which will be significantly shorter without a fluid change. Would you not change the engine oil? Or the brake fluid? How about the coolant?

Here's a good rule of thumb. "Transmission fluid is cheap, but a tranny ain't"