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Old 07-02-2010, 05:16 PM
Mark@EAC Mark@EAC is offline
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Location: NW Indiana USA
Join Date: Nov 2008
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Mein Auto: e39 5
540i/M5 wishbone ball joint press- now in affordable version!

The mission:

Provide a wishbone ball joint press tool for the e39 V8 cars that is not only affordable, but that one could build on their own for minimal investment from readily available materials. Buy it cheap, or build it even cheaper.

The e39 540i and M5 have a long tapered ball joint at the wishbone location. This ball joint is taller than most and because it is situated directly under the strut it can be very troublesome if not impossible to remove without a special press. This same ball joint on the I6 e39s is about an inch shorter for whatever reason. BMW offers a ball joint tool, for around 300USD. The BMW tool will open wide enough to remove V8 wishbone ball joints, but it is too expensive for those of us who will not use it more than once or twice.

I had purchased another similar press from ZDMAK for around 50 dollars hoping it would work. 50 sounds way better than 300. It does not open enough to remove the wishbone ball joints from a V8 e39 unfortunately. It now rests at the bottom of my tool box, waiting for me to find some other use for it.

Harbor Freight tools offers what they call an import ball joint press for less than 20 dollars. It is actually very high quality for the cost, I love it.
If you have a 525i/523i/528i or 530 you are in luck because that 20 dollar press from Harbor Freight will handle any ball joint on the front end of your car. Sadly, the harbor freight tool does not open up enough to remove the V8 wishbone ball joints.

Unless we modify it. In thinking about a solution to my own task at hand I realized I could fabricate a new upper jaw for the Harbor Freight ball joint tool. In finding this solution I then realized any 540 or M5 guy might want to remove these ball joints without spending 300 dollars or beating the car with hammers and pickle forks for 3 hours per side. So here we are.


Originally I drew up a taller top jaw for the HF press that was to be machined from a single piece of steel. When I submitted the drawing to a machinist friend he asked me to bring him the HF press tool so he could look at it along with my drawing. When I saw him again he had made me a new taller top jaw. It was just a few bars of steel welded together, he said it took him about 30 minutes. It was not pretty like my drawing, but it was sure beefy looking. If he were to mill the piece I had originally drawn out of a single piece of steel it would have taken him much longer- and he would have wanted more money. He gave me the jaw and asked me to try it. If it needed to be changed he would change it. Some pics of the tool:

The test mule:

The maiden wishbone ball joint I removed was attached to a 1997 540i auto, with a build date of 5/1996. As crusty and old of a ball joint as I could find. The wishbone appears to be factory installed. If it was replaced it was not any time in the last 5 years by the looks of it. I jacked the car and put it on a stand. No lift for this test. Just like anyone else might do it, in the driveway. After I had removed one end of the sway link and lowered the wheel carrier from the strut a bit the modified HF tool removed the ball joint in all of 30 seconds. I am quite pleased with the results. The wishbone in the video is the opposite side of the same test car.

If you are removing the arms for replacement it's really no concern but I wanted to mention that this tool removes the ball joint with no damage to the car or the joint itself. Some may be removing the arms to press in new bushings. The tool we made will make sure your ball joint can be reused, if you want to go that route.

So to duplicate this setup you just need to get the harbor frieght press, and make or buy the upper jaw for your wishbone ball joints. Pretty simple.

If you would like to build one yourself the dimensions are provided below. I can not be held responsible for any accidents or mishaps you might experience while building or using this tool. If you use good steel and can weld confidently you should have no issues. Note that the tool I had made was welded with a 240V gas shielded, wire feed Miller welder. To find the right drill bit to make the pin hole just compare it to the pin and try to center the hole better than my friend did!
The bottom bar in the stack that the screw pushes against can be any length, about 1" is fine. That part is essential since the screw is too short without it.

If you do not have access to metal working gear as most of us don't you may PM me and I will arrange for you to purchase the custom upper jaw for a VERY reasonable price. I told the guy that made it for me I may need a couple few more in the future. We have already discussed some very slight changes but overall the custom upper jaw will be the same cost effective design. I'm not looking to make anything here, I will charge his cost + shipping. I don't expect to sell many, but if you need one, just ask.

Little video demonstration. Note that the light tapping with the hammer would not have been needed had I loosened the bolt through the bushing side first. I was trying to think about 3 things at once and forgot to loosen it first.

And finally a picture of what your wishbone bushings might look like if they are original. This car had 160k miles on it.

Did you change your thrust arms only to still have the shimmy? Getting some nasty front tire wear? Look at the bushings in your wishbones. They might be trying to tell you something.

Thanks for reading/looking.

Last edited by Mark@EAC; 07-02-2010 at 05:47 PM.
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