05 BMW X5 4.4i Trans Nightmare

[Quicksilver]

Originally Posted by wpoll

Not sure I'd recommend either without further evidence that this issue is casued by the transmission.

Having said that, a re-programme wouldn't hurt anything. I think the transmission would need a full re-adaptation if reprogrammed though (not hard).

When mine gave me problems reprogramming helped a lot. All I did was stop. turn the engine off. Then turned it back on to ACC without starting. The pressed the accelerator to the floor for 30 seconds. This method cleared out what the Transmission has learned over the previous months and allows it to begin to learn a new driver. No Guarantees but it worked for me. And lots of people on the site have done it. It also cleared up the rear end thud ( like someone rear ended you ) as well.

[X5only]

Originally Posted by Quicksilver

When mine gave me problems reprogramming helped a lot. All I did was stop. turn the engine off. Then turned it back on to ACC without starting. The pressed the accelerator to the floor for 30 seconds. This method cleared out what the Transmission has learned over the previous months and allows it to begin to learn a new driver. No Guarantees but it worked for me. And lots of people on the site have done it. It also cleared up the rear end thud ( like someone rear ended you ) as well.

Very interesting about the rear end thud. A couple of years after getting my 2005 CPO, it starting getting that rear end thud. After lots of troubleshooting by the dealer, they ended up replacing the trans under warranty. 10 years later, it started the same rear end thud. It's still there now and I've been planning to replace the solenoids, sleeves and filter. It rarely happens but I found a reliable repro step is to drive up a hill and stop. When taking off slowly, the thud could happen about 4 of 10 tries. I should try what you said and see if that thud goes away. The thud is pretty strong, like someone is really upset with you and unleashes a mighty rear end

[abnewy]

Apparently this is a well known problem with no solution. Here is one thread about it:


https://xoutpost.com/bmw-sav-forums/...bang-rear.html


Jaguar S-Type ZF Gearbox Lurch fault

Originally Posted by X5only

Very interesting about the rear end thud. A couple of years after getting my 2005 CPO, it starting getting that rear end thud. After lots of troubleshooting by the dealer, they ended up replacing the trans under warranty. 10 years later, it started the same rear end thud. It's still there now and I've been planning to replace the solenoids, sleeves and filter. It rarely happens but I found a reliable repro step is to drive up a hill and stop. When taking off slowly, the thud could happen about 4 of 10 tries. I should try what you said and see if that thud goes away. The thud is pretty strong, like someone is really upset with you and unleashes a mighty rear end

[crystalworks]

From what I have gathered, and I'm no expert so keep that in mind, this is related to wear of the valve body (solenoids, seals, springs, etc) and/or seals that seal the VB to the trans fluid passages. Done so much reading on the ZF transmissions as I have 4 of them currently, 2 of which are misbehaving.

I have the "slam" or "being rear-ended" feeling in the 4.8is during 2-1 gear changes which I avoid by coming to a 100% complete stop at every light and stop sign and waiting for the gear change before pulling away. Or, by manually shifting the trans. I am going to try a couple of valvoline fluid services first to see if there is improvement.

I also have a "trans failsafe" fault on our ZF6hp26z in our e70 deisel. I forget the codes but they are for 3-4 gear ratio monitoring. This one required a replacement trans as the failure is internal to the trans itself (E clutch bearing failure). I tried a VB rebuild first and a few fluid services as part of a path of least resistance approach but to no avail.

Some have reported improvements after transmission relearns. Worth a shot as it's easy and costs nothing. Some have reported much better shifting after VB rebuilds. Some have reported better behavior after just a fluid service using Valvoline Maxlife multi vehicle (thicker than ZF lifeguard 6) or other fluid like Redline, Pentosin, Lubri Moly. I am almost 100% convinced these problems are due to BMW ignoring ZF's recommendation to service the 6hp (and other models) transmission every 60-80k miles depending on service life. Lifetime hydraulic fluid just isn't a thing.

PS: If you want a good read about the 6hp and fault causes, this is a good place to start.

https://axleaddict.com/auto-repair/Z...E-Clutch-Fault

[haigha]

Originally Posted by crystalworks

...Some have reported improvements after transmission relearns. Worth a shot as it's easy and costs nothing. Some have reported much better shifting after VB rebuilds. Some have reported better behavior after just a fluid service using Valvoline Maxlife multi vehicle (thicker than ZF lifeguard 6) or other fluid like Redline, Pentosin, Lubri Moly. I am almost 100% convinced these problems are due to BMW ignoring ZF's recommendation to service the 6hp (and other models) transmission every 60-80k miles depending on service life. Lifetime hydraulic fluid just isn't a thing....

Great info, as usual! Shifts are still smooth after my three drain / fills with Valvoline MaxLife. That was in summer / fall 2019. Drove back from lunch with my window down today. I was amazed at the quietness of my 17.5 year old! Loving the Yokohamas I put on:

https://xoutpost.com/bmw-sav-forums/...ndar-x-cv.html

My problem may not have been the quality of the fluid since my mileage is currently around 42k on my 04 4.4i. It looked very good and no debris on the magnets when I replaced them, the fluid, the sleeve, the gasket and the filter. The fluid was definitely low because of the leak at the mechatronic sleeve. However, in contrast to BMW, ZF does recommend replacing the fluid every seven(IIRC) years, even if you don't hit 60-80k miles. Mine was more than double that age in 2019.

One thing I didn't mention when I posted in 2019 is that my mechanic friend and I used the side fill port on the transmission, instead of the one on the bottom. I measured the height of the top lip on the bottom one and it was a tiny bit lower than the side port. When I researched before doing the service, I read that BMW slightly overfills the ATF at the factory to help in case of a leak. So far, no ill effects from using the side port. I used the Foxwell to make sure the ATF temperature was in the correct range and refilled after running through the gears after the initial fill, as I recommended here and other sites.

I didn't do the relearn on the transmission. Even though it was an option with my Foxwell, I figured I'd see if the harsh 1-2 shifts went away before doing it. They did.

[Hoopie]

The only time I have had a problem going up a hill is when my ZF trans was shot. I pulled and had it rebuilt, problem solved