[TassieBMW]

My 2005 E90 330i with the ZF 6HP19 is starting to experience some slipping from the gearbox at slower speeds. While it's not too bad for the most part, occasionally when you go around a 90 degree turn at very slow speed it will actually loose power completely for a second or two before slowly starting to pick up again.

The car has about 250,000km (155,000 miles) on it so it is getting up there. I had my mechanic do a trans service at 180,000km (111,000 miles) which included a new pan and filter plus electrical sleeve and new Liqui Moly top tech 1800 fluid. I've since heard that it's best not to change the fluid after 100,000 miles if you haven't already as this will be bad for the gearbox, and I guess that theory is proving accurate.

Is there anything I can do to reduce slipping and improve shift quality or has this gearbox come to the end of its operational life?

TIA

[Sgop335]

Have you heard of xhp?not sure if is compatible w your model but easy to chk.
Xhp is excellent as it can read transmission adaptations. The adaptation values tell a story, if its too high etc. that may help how bad it is

[TassieBMW]

Originally Posted by Sgop335

Have you heard of xhp?not sure if is compatible w your model but easy to chk.
Xhp is excellent as it can read transmission adaptations. The adaptation values tell a story, if its too high etc. that may help how bad it is

Just had a look at their website and looks interesting. I guess I'd have to buy their software just to read adaptations though? Not so keen on that.

I have ISTA and INPA, not sure if there's any way to read adaptions with them.

Would be great to know if the cause of the slipping is related to the torque converter or clutches or if the valve body needs replacing.

[Sgop335]

Reading adaptations and codes is free

[jericho_17]

Or you could also been proving the theory that should use OE fluid in these ZF transmissions

[TassieBMW]

Originally Posted by jericho_17

Or you could also been proving the theory that should use OE fluid in these ZF transmissions

I've been lead to believe that Liqui-Moly is either as good, if not better than the ZF fluid. Obviously they're a German company that specialise in high-quality lubricants so I can't see their products being bad for the gearbox.

[jericho_17]

Originally Posted by TassieBMW

I've been lead to believe that Liqui-Moly is either as good, if not better than the ZF fluid. Obviously they're a German company that specialise in high-quality lubricants so I can't see their products being bad for the gearbox.

But you dind't drain the whole fluid and i'm pretty sure that Liqui Moly specifies not to mix with other brand of fluids.

[TassieBMW]

Originally Posted by jericho_17

But you dind't drain the whole fluid and i'm pretty sure that Liqui Moly specifies not to mix with other brand of fluids.

The mechanic who did it is a master tech with 15+ years experience so I'm sure he drained the fluid correctly.

[timnkoo]

Can't provide a solution, however, a casual observation does seem to reveal more gearbox related issues with gearboxes that have used alternative fluid to the genuine OEM ZF Lifeguard 6. As mentioned by others above, I would also personally only ever use the genuine ZF fluid. Just not worth the few $$$ saved IMO. Hope you get it sorted mate.

[jericho_17]

Originally Posted by TassieBMW

The mechanic who did it is a master tech with 15+ years experience so I'm sure he drained the fluid correctly.

Unless he used a flush trasnfer machine (which is not also recommended by ZF) he drained like half of the fluid leaving the torque converter with the old original fluid.

[F31B48]

Have you checked the fluid level in the trans? That would be the first thing to check, and also fault codes.

Like others have said, it's not really a good idea to use aftermarket trans fluids. Use ZF fluid only.

[TassieBMW]

Originally Posted by jericho_17

Unless he used a flush trasnfer machine (which is not also recommended by ZF) he drained like half of the fluid leaving the torque converter with the old original fluid.

Are you suggesting that it's necessary to pull the trans out along with the torque converter to do a fluid change? Because if so that's a ridiculous comment.

[TassieBMW]

Originally Posted by EvaBmw

Have you checked the fluid level in the trans? That would be the first thing to check, and also fault codes.

Like others have said, it's not really a good idea to use aftermarket trans fluids. Use ZF fluid only.

Fluid level is good, no fault codes either.

I would never use a low quality aftermarket brand, Liqui-Moly have a reputation for being better than OEM and are experts within the lubricants business, so I don't think there's anything wrong with their product. Sure, seeing the ZF logo on the bottle might make some people feel better but at the end of the day if you looked at the chemical engineering of both fluids I'm sure there isn't a tremendous amount of difference.

These gearboxes are known to have issues over time due to the 100% torque converter lockup in first gear that they are capable of, so I would put down my gearboxes issues to high mileage (255,000km), potentially a worn valve body and primarily worn internal clutch packs and of course the torque converter.

I highly doubt the choice of Liqui-Moly fluid is to blame.

[jericho_17]

Originally Posted by TassieBMW

Are you suggesting that it's necessary to pull the trans out along with the torque converter to do a fluid change? Because if so that's a ridiculous comment.

I'm not suggesting, I'm stating you mixed fluids which was your second mistake in this process, using not OE fluid was the first.

[TassieBMW]

Originally Posted by jericho_17

I'm not suggesting, I'm stating you mixed fluids which was your second mistake in this process, using not OE fluid was the first.

I didn't do it though you see, the mechanic who did was (as I already mentioned) a highly experienced BMW master tech. He was the one who reccomended the Liqui-Moly fluid, and for all I know he did drain all the fluid, but I can't imagine he pulled the trans to do it because who on earth does that?

Either way, approaching 260,000km the 6HP19 will be getting tired no matter how good a life it has lived, so I'll probably just look at getting a used one with low mileage and putting in the car.