2006 4.4 5th gear lurching

[upallnight]

Originally Posted by Duc

Hey everyone, I just recently picked up my first X5. I just wanted to say that I've already solved a bunch of little issues and installed an OE AUX cable all thanks to this forum.

Well, about 30 minutes after driving away with the X5 after purchase I noticed a bit of a transmission issue while stuck in rush hour traffic that didn't rear it's ugly head while I was test driving it. As it was a private sale, I am now stuck with fixing it myself.

First a bit of back story. The car only has 149,000 KM on the clock. BMW warranty claims history shows that a new transmission was installed at 29,000km. So the tranny is a little younger than the rest of the car.

Under warranty the P.O. took it in for hard shifting about a month or so ago. BMW replaced the seals on the mechatronic unit (square one, and the one that notoriously leaks at the terminal), as well as the 4 little round ones and put all new fluids and filter in. The P.O. believed this fixed the issue (which it likely mostly did). Unfortunately the real issue was never identified by the P.O. or BMW and now the X5 is out of warranty.

Alright, so onto the issue.

1. Intermittent hard shifts from 1st to 2nd when cold. Seems like it holds the gear too long and then drops it hard into 2nd. If you let the tranny get up to temp for a few minutes in the morning this issue isn't present. But if you hop in and go, bang, hard shift. Rest of the shifts after that are buttery smooth, even the next 1-2 shift.

2. Now this is the one that really worries me. When in 5th gear the transmission feels like it's skipping or lurching. This is ONLY in 5th gear. RPM stays steady. It almost feels like the transmission is going to shift. I can get it to do it consistently if I stay in 5th in manual shift mode, or if the trans selects 5th while in regular D. This isn't present in any other gears. There is no other slipping in any other gears, everything else is buttery smooth.

Based on my research, I think both of these issues will be fixed with a rebuild of valve body using a zip kit and new ZF solenoids. But I would like to know for sure. I'm hoping an expert on here can tell me whether or not issue 2 is likely to be resolved by the valve body refresh, or if you think its an issue inside the transmission itself. I'm really hoping it's not a bad clutch pack.

Any insight would be greatly appreciated here!

Thanks everyone! Oh, and I've included a shot of the new X5 if anyone is curious. It's a sport package and I have the factory 19" wheels with it, these are just for winter.

Hopefully RPhil will chime in on this or go to youtube and check out Gary Ferraro's videos on the ZF5hp24 trans including his video on valve body rebuilding. If it was my X and I was going to pull the valve body out I will just ship it to Gary's shop and have him rebuild the valve body. Too many check balls and orifice tubes that can be installed incorrectly

[Duc]

Originally Posted by upallnight

Hopefully RPhil will chime in on this or go to youtube and check out Gary Ferraro's videos on the ZF5hp24 trans including his video on valve body rebuilding. If it was my X and I was going to pull the valve body out I will just ship it to Gary's shop and have him rebuild the valve body. Too many check balls and orifice tubes that can be installed incorrectly

I'm hoping RPhil sees this post as well. I have seen some amazing contributions by him in other threads.

I've watched all of Gary Ferraro's videos on the ZF6HP26, he has some great tear down and valve body rebuild videos.

I'm in Canada, so shipping the VB to his shop might not be worth it, I may be better off just buying a reman from a ZF distributor directly.

Although based on my reading and the countless videos on the subject I have watched I am confident in my ability to rebuild the valve body myself. I also work at a motorcycle dealership (BMW, Ducati, Triumph) and have many sources of information if I get stuck. I also have people I can trust that I can get to rebuild it for me.