The retaining ring I had found at the local hardware store lasted about three weeks, and off it came again. Now, I figured out a bit more of a substantial fix. I couldn't figure out how to get a fastener into the end of the ball (through the side of the cylinder base), as it is so close to the side of the trough in the car body that it is housed in when it is mounted onto the cylinder. We couldn't get a fastener long enough in there. So, we drilled a small hole in the cylinder base, top and bottom, at the base of the ball, and inserted a set screw on each side. So far that is holding well.


Side note - I just spent two hours yesterday, swapping out the electric tailgate risers on my wife's '09 X5 for a set of the standard gas pneumatic risers. That stopped working about three weeks ago, and my indie guy told me the passenger-side electric lift strut had gone bad. He talked with his parts guy at the local BMW dealership about ordering a replacement, and he said they were out of stock in them. Parts guy admitted that they go through so many of them (at $350.00 a pop, plus installation, so I figure they probably take you for at least $500.00 to do the repair), that they can't keep them in stock!! BMW's parts guy RECOMMENDED that I just put a set of the regular gas pneumatic struts on the car. So, I took his advice, and $110.00 later I have a trouble-free tailgate. Long story short, BMW can't build a reliable power tailgate, and they know it!

 

Any pics? I dont really understand how you made this mod. Thanks.

 

Just wanted to report that my 2009 E61 535 x-drive also has this problem. The key issue is not that the lift isn't working--it works fine. But the ball/socket attachment at the mount point for the strut no longer "holds." It appears that the clamping/holding mechanism has corroded. Like some others here, I'm looking for options that don't require replacing the whole assembly. I'll report back if I encounter any.

 

PS--Would anyone be willing to measure the size of the ball for me? 10mm? 13mm? Something else? I'd go do it myself by my tailgate isn't opening right now.

 

I suggest a lock cylinder. Find some tubing (square might be better) that JUST slips over the end of the gas strut and then cut a slot on one side that barely slips over the neck of the ball. the slot should only go to about the middle of the piece. That should pivot, but hopefully not allow the cylinder to pop off. It's this idea, but doesn't have the large hole so it can slip over the ball.


Jose

 

This was already done on the touring I bought and I don't miss the power functionality at all.

My wife's MDX has the power liftgate and truthfully, we only used it a handful of times throughout our ownership thus far. Otherwise we normally shut it manually most of the time.

 

Here's a pic of the lower set screw that we put in the base of the cylinder. We did the same thing on the top side. You have to prop the tailgate up and take the cylinder off of both of the ball mounts to do this. Still holding after a couple of months!

 

I have a 2008 e61 and I too have the same problem. The socket of the lift cylinder is aluminum and yes, over time, the ball corrodes creating a lapping compound out of the rust wearing the socket. Once the wear is sufficient, the socket hole is large enough for the lifting force of opening the glass to pop the socket off of the ball.


What I did (this is a temporary fix - I know) is this:
- I swapped ball studs left to right. I noticed that the lift cylinder ball had worn a flat spot, essentially it was smaller in diameter. I tried buying new but my BMW parts dealer sold me the wrong ball. The manual lift gate e61's use a ball stud with M8 thread. The e61 with power lift gate use a ball stud with M10 thread. Anyway, this helped a bit.
- I cleaned and relubed the lift cylinder socket. This did little - it kept popping off
- I replaced the right lift cylinder. I assumed that maybe the right cylinder has weakened, causing more force against the socket of the lifting cylinder. The old one didn't feel 'bad' but no gas spring lasts forever.
- Next I inspected the socket and realized the orientation of the spring clip (c-clip). The opening of the c-clip was in the same area of the damage on the socket. Using a small screwdriver, I rotated the opening 180 degrees. Small detail, but since this last change, the cylinder hasn't popped off since. It may be a combination of the clip rotation and the right cylinder replacement but my fingers are crossed. If it fails again, I will go into engineering mode and devise a more permanent fix (I'm an engineer and have access to a shop full of machinists and shop equipment.)


I'm glad and sad to hear that I am not alone. Sucks that the replacement cost is so high. BMW could have made the hydraulic and electrical connection at the cylinder to make replacement easy, but that would starve its service department of much needed unjustly gained funds.


My thought at a more permanent repair are to possibly drill and tap a small, perpendicular hole (or two) near the opening of the socket and inserting a small set screw (M3) with a brass tip. You would install the socket onto the ball stud, then insert the set screw. Drilled in the proper place, the brass tip would act as a stop - it would effectively 'close' the opening. I will post a sketch later after talking this over with my lead machinist.

 

Great info gsodonis--please keep us posted.

 

Here's the pic of the lower set screw that I installed on the base of my hatch cylinder. Did the same thing on the top of the cylinder as I described in my previous post. We did this mod (along with a new ball pin) about 5 months ago, and so far so good. BTW - I got my ball pin from Pelican Parts, part #41-62-7-148-797-BOE. It's an OEM BMW part....would have just ordered it from my local dealer, but I was ordering brake parts as well, so I just combined the order. Cost me $5.50.