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Lower ball joint

8K views 11 replies 7 participants last post by  johnathan1 
#1 ·
---Quote (Originally by Rupununipete)---
Ball joints are fairly easy. With the lower control arm supported you will want to remove the calipers and rotor for easier access. Removing the hub and backing plate is an option but will require a dial-gage to set the wheel bearing play on reassembly, so keep that in mind (half a thousands of an inch)

Back both the nuts off until flush with end of threaded shaft. I personally heat up the spindle with a torch in the area that holds the ball joint to avoid having to beat on stuff and then give it a good square faced smack with a 3 pound hammer and it comes loose every time, even on this well corroded daily driver with what looks to be original suspension. You will need to retain the big nut on the spindle connection for the new ball joint, so hit it squarely and don't beat it up. :) on assembly torque to 140 Nm

You then give the same square smack to the top of the ball joint with the lower control supported on the floor jack. Spin the nuts off and replace. Torque control arm nut to 100 Nm.

Keep in mind that the coil spring is only kept under compression by the floor jack under the control arm and weight of the car. Lowering the jack once the ball joint is loose will result in a lot of excitement and possible terminal injury, so be bloody careful! The safest way is to retain the spring is with a proper compression tool, but not necessary if you are careful.
---End Quote---

Thanks for the advice and encouragement! I have the proper spring compressor so I may use that.


Would you mind commenting on this guy's DIY? he mentions putting the ball joint into the control arm first and then swinging it into the spindle hole in order to better align it. What do you think?

W140 Ball Joint DIY Guide - PeachParts Mercedes ShopForum

Also, I am not sure if I have the replacement nut for the backside. It is alright to reuse it?

Thanks again!
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End Quote

The article in Pelican Parts is correct in that it is best to situate the ball joint in the control are first. You can reuse the nut to situate the ball joint in the spindle. This is why you want to take care when you knock it out of the spindle in the first place.
 

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#2 ·
Did this job. One question:

Should the ball joint be flush with the steering knuckle? This is as far as I could get it wiggling, pounding, and using the impact on the nut.





The other side that has been on the car since I bought it from the PO has the same amount of clearance and isn't flush either. So either they screwed up before or that's the way it is supposed to be.
 
#4 · (Edited)
Great thread...

Our west coast cars have no rust, so suspension parts come off really easy( they were easy on the cars I had to replace the ball joint). I used a fork with a few good blows.

Do buy the spring compressor. Life is too fragile If I show up at your funeral, and say " he could be with us if he would have spent a few hundred dollars for a tool". You bet, your wives would have given you $200 - $300 to bring you back... USE A SPRING COMPRESSOR.

Safety first guys...

Respirator/Hearing/Eye/Gloves/Spring Compressor

Martin
 
#8 ·
On my w140 we did compress the springs the worker said i would never touch the w140 suspension without compressing the springs. Lower ball joints came out with little to no effort but i am going to replace it again because the dust boot ripped for some reason same for my tierods i used dealer parts 2 years ago. I did my shocks in my friends garage and without compressing the springs we couldnt mount the shock top mount. The amg coils are really stiff but the regular mb coils are softer. I have seen people ghetto rig jigs for springs but i would recommend getting spring compressor the $300 isnt worth the cost of severe injuries/death. These springs are under alot of pressure. It literally sound like a 7.62 bullet going off when loosened the shock and spring popped we installed the wheel and got away from the car popped the top bolt off just incase to avoid any injuries and i wouldnt recommend doing that.
 
#9 ·
The reasoning for not using a spring compressor on a W140 when doing the ball joints is that the sway bar links keep the LCA in place. On a W126, the sway bar is on the top, thus when the LCA is removed from the ball joint, there is a potential for the LCA to drop and expel the coil spring.

Here is a video from youtube where they have the car on a lift and did not use a spring compressor. I even asked why they didn't support the LCA and they said there was not enough compression on the spring.



Here is the PDF from Pelican:

http://www.peachparts.com/shopforum...diy-guide-w140-lower-ball-joint-diy-guide.pdf




One question I do have: when should we replace the springs? Mine have surface rust but aren't broken. Do they take a 'set' over time?
 
#10 ·
Please note that they had brand new sway bar links and bushings on the demo car in the video. If the links are worn and sloppy, I wouldn't trust them to hold against the spring. They could come apart with catastrophic results.

Yes, springs do take a set over time. How much, and whether they need replacement depends on how rusty they are, the road conditions the car has seen, and the material properties of the steel. Severe rust coupled with the stress on the springs can cause corrosion to be accelerated thus weakening them, and can even cause the springs to ultimately break.

Sent from my Nexus 5 using Tapatalk
 
#11 ·
Used old suspension parts can rip apart from the tension/pressure. Esspecially the tiny sway bar links. The springs have a hefty kick to them. Like i said when we dropped the shocks it literally sounded like a ak bullet going off. Sounded like popping a ball joint but soo much louder. I would personally rather be safe then sorry in the states a minimum hospital bill is $1000.
 
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