Thanks for the replies everyone! Sorry in advance if the multi-quoting is incorrect, for some reason the Multi-Quote Button was not working so I had to copy and paste each one individually.
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Originally Posted by wpoll
I would certainly change the mechatronic sleeve while you have transmission open. Changing it won't help with the operation of the transmission in any way but it will fix or avoid a fluid leak, which is bad for your transmission.
I also doubt that just a fluid change will fix your hard 2-1 shift, going by what others have said on here and on other forums for cars that use the ZF 6HP26. I has helped in some cases but not in most.
Some folk have have good results with the fluid change along with a new bridge seal and new jumps seals. One again, while you are in there, why not replace them...?
Others have flashed (or re-flashed) the firmware in the transmission control unit with good results.
I think ultimately it's either new solenoids or a new (or refurbished) mechatronic unit that is the cure.
But it really depends on what exactly is wrong in your transmission and so while there are many seemingly common issues, the causes can vary and so must the action taken to remedy the problem.
Changing the fluid and seals is the first step to finding out I suppose!  |
Thanks for the advice! I figure it might be best to change the sleeve to prevent any future damage to the transmission due to the sleeve failure. And my transmission is fine, it engages gear and shifts smoothly, its just every once in awhile I'll experience the bang if I don't come to a complete stop.
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2002 X5 3.0 345,400 miles - still running original fluid
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Wow that is amazing! Makes me think I could just leave the original fluid in my transmission
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I had the dreaded 2-1 downshift knock and after a fluid change it did get better but only temporarily. Ultimately you're facing a transmission refurb, sorry to say. The mechatronics is fine. The knock is caused by worn bushings creating excessive play in the transmission shaft. I ran with my knocking problems for around 50,000 kms before finally getting it refurbed. Mine is a 2006 X5 E53 3.0D 6HP26. Issues started at 110,000 kms.
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How frequently did you experience the 2-1 downshift knock before your transmission refurb? And how much did it cost to refurb your transmission? Hopefully the day doesn't come soon, but if my transmission would indeed fail one day and needs significant work I will probably end up buying a newer model X5, hopefully I don't have to worry about that until years down the line haha....knock on wood.
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I did the fluid replacement with ZF Transmission fluid and the BMW filter by Bavauto.com. Make sure to follow the recommendations of topping off the fluid with the vehicle level and running, as described in other posts. My 2002 with the same 4.4 shifted good before and after. I just wanted a good look in there after 100k miles. The old fluid looked a lot like the new stuff so I decide on keeping the X5. Two years later and all is well. Good luck!
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Thanks! I was looking into transmission fluid kits from FCPEuro. And they had a package with the ZF Lifeguard oil. Since you're car has been shifting good after two years, I'm guessing the ZF oil is worth the money over Pentosin (which I was looking into buying since its $14 a liter compared to $23 for the ZF.) Also how many Liters of oil did it take for the transmission to be completely full? 9 Liters?
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I'd change all the valve body seals as well while you're in there, that would require pulling the valve body though, so I don't know how confident you are about that.
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I've seen a video on YouTube on removing the valve body, doesn't seem to complicated. But by valve body seals are you referring to the adapter plug?