Airmatic strut ball joint
12-17-2015, 08:40 AM
#1
Senior Member
Thread Starter
Airmatic strut ball joint
Hello,
I have a 4Matic with Airmatic suspension (the 4Matic strut is different from the regular one).
The 4Matic version of the strut has a ball joint at the bottom. The ball joint is part of the strut and not a separate part.
Mechanic has had a few of these cars come in with a clunk in the ball joint. He said they are greased at the factory (there is a rubber boot) but are not greasable again. Once they clunk you have to replace the entire strut even though the air bag works perfectly fine.
He had a few on the shelf.. said he couldn't bear to throw them away because they all worked perfectly, just had a clunk.
Mine is doing it too. I'm thinking of two options....
1. In older cars (W140) the rear struts did this, and he used to drill a hole and pump grease into it, then tap the hole and install a bolt. I was thinking of drilling a hole and threading it, then installing a standard (Zerk) grease fitting. Pump full of grease till the boot expands a bit, then leave it. This is obviously more complex, and I'm also worried that if I do so and it doesn't work, my strut is junk and I won't get the $200 core refund from Arnott if I do end up replacing it.
2. Get a grease gun with needle on the end, and try either a)pushing the needle between the metal and the boot, or b)puncturing the boot and then sealing later with weather strip adhesive. I could fill the boot with grease... not sure if it would eventually work itself into the joint or not. With this heavy of a car, I'm not sure if the grease would work into the joint at all though.
Any thoughts/experiences?
I am trying to give this a shot (the $0 solution
) and if it doesn't work then I'll just have to replace the strut. It works 100% perfect except for a clunk when I hit large potholes or bumps. 95% of daily driving you don't hear it at all.
I have a 4Matic with Airmatic suspension (the 4Matic strut is different from the regular one).
The 4Matic version of the strut has a ball joint at the bottom. The ball joint is part of the strut and not a separate part.
Mechanic has had a few of these cars come in with a clunk in the ball joint. He said they are greased at the factory (there is a rubber boot) but are not greasable again. Once they clunk you have to replace the entire strut even though the air bag works perfectly fine.
He had a few on the shelf.. said he couldn't bear to throw them away because they all worked perfectly, just had a clunk.
Mine is doing it too. I'm thinking of two options....
1. In older cars (W140) the rear struts did this, and he used to drill a hole and pump grease into it, then tap the hole and install a bolt. I was thinking of drilling a hole and threading it, then installing a standard (Zerk) grease fitting. Pump full of grease till the boot expands a bit, then leave it. This is obviously more complex, and I'm also worried that if I do so and it doesn't work, my strut is junk and I won't get the $200 core refund from Arnott if I do end up replacing it.
2. Get a grease gun with needle on the end, and try either a)pushing the needle between the metal and the boot, or b)puncturing the boot and then sealing later with weather strip adhesive. I could fill the boot with grease... not sure if it would eventually work itself into the joint or not. With this heavy of a car, I'm not sure if the grease would work into the joint at all though.
Any thoughts/experiences?
I am trying to give this a shot (the $0 solution
) and if it doesn't work then I'll just have to replace the strut. It works 100% perfect except for a clunk when I hit large potholes or bumps. 95% of daily driving you don't hear it at all.
12-17-2015, 06:34 PM
#2
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Join Date: Dec 2005
Location: Rochester, NY
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2009 S550 AMG sport pckg. 2014 Ford F-150 Lariat Supercrewcab
Once it clunks it means there is too much clearance between the ball part and housing and greasing will not do you any good. It is a nuisance to hear a clunk on 100k dollar car though. I wonder if they can be pressed in/out or if they are built into the strut
12-17-2015, 10:21 PM
#3
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S550
They look like they can be, I noticed it when I did a replacement with an Arnott, though the old ball joint was okay, mine was an air leak......I imagine replacing the ball joint is part of what Arnott does when remanufacturing them. The old style upper control arms though, you can clearly see it is one-piece, the ball joint is part of it and needs to have the whole thing replaced (this was revised around 2009? The new control arms allow you to replace just the ball joints)....These cars are really heavy and wear these ball joints out pretty quickly, almost unreasonably quickly....Mercedes would classify it as a wear item! Like they did my loose hood ornament!
