[rhmarquez]

My 2014 435i automatic sport transmission slipped today while I was doing a med-high pull from 1st to 2nd gear. After that it seems to be working normal again. I drove it pretty soft after that and tried again some pulls and it worked fine. Ever since I got the car (like 20,000 miles ago) it jerks a little bit on the initial 1st to 2nd gear change just after a cold start and then it's normal. Do you think at 84,000 miles it would be a good idea to change the fluid using FCP's kit, or am I too late and should just ride it out?

[thejeremyman9]

Originally Posted by rhmarquez

My 2014 435i automatic sport transmission slipped today while I was doing a med-high pull from 1st to 2nd gear. After that it seems to be working normal again. I drove it pretty soft after that and tried again some pulls and it worked fine. Ever since I got the car (like 20,000 miles ago) it jerks a little bit on the initial 1st to 2nd gear change just after a cold start and then it's normal. Do you think at 84,000 miles it would be a good idea to change the fluid using FCP's kit, or am I too late and should just ride it out?

The 'lurch' (as it is typically called) on the first 1-2 cold shift is normal, even for lower mileage cars and cars that have changed fluid.

https://f30.bimmerpost.com/forums/sh....php?t=1715453

How sure are you that the trans slipped and it wasnt something else?

ZF recommended interval is 100k km, so 62k miles. You will her 2 schools of though - the 'its too late' and changing it will make it worse, and the 'better late than never'. I don't think there's really a definitive answer, you will just need to make a decision. I have heard of people changing it around the same time or later, but YMMV, especially if it does have issues and it was a hard 84k.

[rhmarquez]

Originally Posted by thejeremyman9

The 'lurch' (as it is typically called) on the first 1-2 cold shift is normal, even for lower mileage cars and cars that have changed fluid.

https://f30.bimmerpost.com/forums/sh....php?t=1715453

How sure are you that the trans slipped and it wasnt something else?

ZF recommended interval is 100k km, so 62k miles. You will her 2 schools of though - the 'its too late' and changing it will make it worse, and the 'better late than never'. I don't think there's really a definitive answer, you will just need to make a decision. I have heard of people changing it around the same time or later, but YMMV, especially if it does have issues and it was a hard 84k.

Glad to see the lurch is normal! Yeah, I drive it pretty normal with the occasional sporty pull, but I'm pretty sure the previous owner drove it spirited since the car had a tune and other sporty upgrades when I bought it. So I guess I'm a little bit out of the recommended fluid change, specially if its been driven that way...

I would think what I felt was a slip because when I changed gears using the paddles the RPM kept going up for a little bit more than normal, followed by a pretty hard jerk into second gear. But it's weird that after that hiccup it's all back to normal...

[F32Fleet]

The current (1/07/20) recommendation by ZF is 150,,000 KM. (90,000 miles) regardless of operating environment.

This is a change from years past which was lifetime fill OR 80k-120k km for vehicles driven in sporty manner, frequent towing, or top speed hwy driving.

[oceanview]

I've just had flushed and changed the transmission fluid this week at our ZF service center.
As already mentioned the ZF recommendation is around 100'000km.

Option 1 would be just to change the Oil without flushing the whole system.
Option 2 would be to completely flush the Oil.
ZF will also change the internal Oil filter and the plastic Transmission Oil housing.

In our country many police departments use BMW cars. The ZF Service Manager told me, that since the police departments started to do frequent transmission oil change, they have almost no repair of ZF 8HP transmission anymore from these police cars. And these cars run under heavy conditions!

[thejeremyman9]

Originally Posted by F32Fleet

The current (1/07/20) recommendation by ZF is 150,,000 KM. (90,000 miles) regardless of operating environment.

This is a change from years past which was lifetime fill OR 80k-120k km for vehicles driven in sporty manner, frequent towing, or top speed hwy driving.

This is the current recommendation for our ZF8, or for other ZF8 models used in other cars/platforms?

[F32Fleet]

Originally Posted by thejeremyman9

This is the current recommendation for our ZF8, or for other ZF8 models used in other cars/platforms?

All 5-.6-.8- and 9-speed as well as the 4HP20.

Scroll down to the TE-ML 11 (Manual, DCT, AT for cars)

https://aftermarket.zf.com/us/en/aft...n/lubricants/#

[thejeremyman9]

Originally Posted by F32Fleet

All 5-.6-.8- and 9-speed as well as the 4HP20.

Scroll down to the TE-ML 11 (Manual, DCT, AT for cars)

https://aftermarket.zf.com/us/en/aft...n/lubricants/#

Thanks. I would note that it does say:

"...ZF recommends an oil change after 150,000 km for its transmissions. In operating conditions with high temperatures and loads, or with unknown vehicle use in the past, it can make sense to change the transmission oil at shorter intervals."

So shorter interval might make sense for a tuned car, or one that sees track time or something. In any case, for OP, i would still lean toward changing it now unless you plan to just get rid of the car in the near future.