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DIY - Lower Ball Joint replacement

22K views 14 replies 11 participants last post by  AndyW 
#1 · (Edited by Moderator)
Hey all, I did a search but figured I would add a post.

I am changing my ball joints on my 98 SLK230 with 211k on it.

I got the ball joint out, but the locating pin stayed on the a-arm. The replacement ball joint has its own locating pin on it.. I was told to remove the locating pin from the replacement ball joint as the one on the car could break then I would have to replace that part.


Any ideas on how to remove this locating pin ?



http://www.partsgeek.com/catalog/1998/mercedes/slk230/suspension/ball_joint.html


Thanks in advance...
 
#2 ·
2000 SLK 230/320 Lower Ball Joint Replacement done easy

The lower ball joint replacement is actually a very easy task on the 2000 SLK (both 230 and 320). All you need is an impact wrench (powered or air), an 18 mm socket for the brake caliper, a 22 mm socket for the lower ball joint and a ball joint extractor. I hate to hammer on my car and I would never let anyone do such to my car. Using the extractor tool, you won’t need a hammer at all.
For this job I use a modified HFT ball joint extractor, but various similar tools are available. This one, modified will accommodate all ball joints on the 2000 SLK. Basically, I used a grinder to deepen the shape of the “U” which goes on the fixed part. When performing the mod on the tool I took into consideration that this will weaken it, but practical use of it told me it did not. Total cost of the extractor: $19.99 (HFT)
Replacing the lower ball joint does NOT require a new alignment since there is no adjustment to be performed. (Tie Rod End replacement requites a new alignment!!!)
Also using the extractor instead of a hammer will not give you any headache with the alignment pin.
My photos will show the tool, the ball joint, old and new and how to position the tool.
I do hope this helps since I did not find a detailed write-up for this matter.
P.S. Please be aware that the “Billstein” ball joints sold for ~$22 are made in Turkey. For someone like myself, originally from Germany, this would be the worst source for car parts. I had to put them on, but I will pay a lot of attention to them and prepare for better ones in the near future.
 

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#3 ·
The lower ball joint replacement is actually a very easy task on the 2000 SLK (both 230 and 320). All you need is an impact wrench (powered or air), an 18 mm socket for the brake caliper, a 22 mm socket for the lower ball joint and a ball joint extractor. I hate to hammer on my car and I would never let anyone do such to my car. Using the extractor tool, you won’t need a hammer at all.
For this job I use a modified HFT ball joint extractor, but various similar tools are available. This one, modified will accommodate all ball joints on the 2000 SLK. Basically, I used a grinder to deepen the shape of the “U” which goes on the fixed part. When performing the mod on the tool I took into consideration that this will weaken it, but practical use of it told me it did not. Total cost of the extractor: $19.99 (HFT)
Replacing the lower ball joint does NOT require a new alignment since there is no adjustment to be performed. (Tie Rod End replacement requites a new alignment!!!)
Also using the extractor instead of a hammer will not give you any headache with the alignment pin.
My photos will show the tool, the ball joint, old and new and how to position the tool.
I do hope this helps since I did not find a detailed write-up for this matter.
P.S. Please be aware that the “Billstein” ball joints sold for ~$22 are made in Turkey. For someone like myself, originally from Germany, this would be the worst source for car parts. I had to put them on, but I will pay a lot of attention to them and prepare for better ones in the near future.
With thanks to your tool advice, I changed over my ball joints on the weekend, I originally bought another brand of scissor type ball joint tool and it gave me a huge headache trimming with an angle grinder. Finally I purchased "Laser 2708". it's a slim profile tool and works well.

Just one more thing to add, You DO NOT need to remove the calliper carriers as suggested; only the two nuts for the ball joint and the actual ball joint. It really is a 10 minute job once you've got the tool modified correctly.

Replaced with OEM parts. Transformed the front end stability.
 
#4 ·
Agree with BLKTAZ that you don't "need" to remove the calipers, however I needed to bend the sheet metal plate to get the tool and ball joints off and on (both sides). It bent back easily enough, mainly the "lip" on it needs to be bent down, then back up. If you don't want to bend it, take off the caliper. It's very thin sheet metal and bends easily.

I got the other side done much faster (not 10 minutes!) after knowing what to do and having the modified Harbor Freight Tool.

The car passed inspection. This saved me $575 dollars. However my car is a "toy" and I could afford to let it sit for two weeks in the garage while I did the internet research. Spent one afternoon shopping at Harbor Freight, several hours online (thank God I found this post). Ordered parts online and waited for them to arrive. So if this was a daily driver, I'd pay them the $600 and be done with it.

Also don't have to listen to my wife "complain" about spending MORE money on my "baby." Put $1,000 worth of Conti tires on it the week before I had it inspected. I am shocked they put the tires on a car with bad ball joints. I am going back to "shame" them into checking my alignment since they missed the bad ball joints.

Next jobs, steering damper and new KYB shocks.
 
#5 ·
blktaz, do you mean that you did not have to modify the laser tool, or just that it was easier to modify than whatever other tool you had?
I had to modify the Laser tool as originally posted by ITAdrian. I did a quick search on HFT for ball joint tools and I'm 99% sure the Laser tool is identical to the $20 piece, possibly re-branded for international sales.


This was the first tool I picked up, as you can see it has a fairly large angle at which the tool begins to wedge, this results in a bulky fit, you'll struggle to get this piece to make good surface contact at where the ball joint and control arm meet.



As you can see from this image, Laser 2708 has a much longer and more importantly, shallower angle at which it wedges. With some modification, as shown in the image below again, you can fineness the tool into place and start turning.





It is kind of disconcerting when you're tightening the bolt, you feel as if it should pop out way before it does, keep turning and it will eventually 'pop'. Possibly need a breaker bar as it requires a lot of force to wind up the tool.

I also found both ball joints 'popped' out not while I was turning the bolt on the tool, but after I stopped. I had got to a point where the tool in my opinion was compressed significantly so I began to sit back and think about the position of it, maybe I had choose a poor angle of attack, but remember, the tool is under huge compression and forces are strong, so as in my case, with enough force stored in the tool, the ball joint thread eventually had no where to go but out the way it came, they makes an almighty sound when they go.
 
#6 ·
To add more detail, the spanner to undo the original Merc ball joint nuts is a perfect 13/16". The nuts on the replacement parts are larger at 22mm as per previous posts.
The joint to remove first is the horizontal lower joint with the pin. Once this is out the linking arm is swung out of the way a little to then enable clear access to remove the vertical ball joint section.

Removal tool hints - as per photos in above posts, the throat dimensions you need to achieve with the grinder are a good 20-26mm (1") at the opening, around 19mm (3/4") dia or more at the deepest point. Most fork tools I have seen are 19mm (3/4" wide) so a good bit needs to be ground out to fit the larger taper size that Merc joints use.
The throat depth is around 40mm (1.5"). Be aware that in order for the tool to work properly, the lever action needs to press into the centre of the ball joint thread shaft. Keep modifying your tool to achieve this centre line force transmission aspect.
Be aware that the tools two supports (that the big pin goes through) can interfere when approaching the 40mm throat depth - so you might need to grind a little of these vertical faces as well.

This job is Not an easy one first time around, but once the tool is modified to suit and you pop your first tapered joint, you can move along methodically.
New lower ball joints are a delight to drive on. The miniature corrections at the steering wheel have been reduced 70%, and no more clicks entering the driveway.
Mine stated to exhibit wear by 60,00kms (36,000 miles) so its a fact they are not long lived in Merc front-ends despite their rugged design.
Anthony
 
#10 ·
Removal tool hints - as per photos in above posts, the throat dimensions you need to achieve with the grinder are a good 20-26mm (1") at the opening, around 19mm (3/4") dia or more at the deepest point. Most fork tools I have seen are 19mm (3/4" wide) so a good bit needs to be ground out to fit the larger taper size that Merc joints use.
The throat depth is around 40mm (1.5"). Be aware that in order for the tool to work properly, the lever action needs to press into the centre of the ball joint thread shaft. Keep modifying your tool to achieve this centre line force transmission aspect.
Be aware that the tools two supports (that the big pin goes through) can interfere when approaching the 40mm throat depth - so you might need to grind a little of these vertical faces as well.
Anthony
The reason the tool is around 19mm (3/4") dia or more at the deepest point is for clearance to enable the tool to be in the correct position when pushed up hard (and up) against the thin metal brake backing plate. (The plate that you folded the bottom lip over and bent out of the way a little, and will bent back neatly when job is finished).
Attached is a pic of my modified tool that worked well.

Tool hex bolt tightening - I agree with other readers that when you think any more tightening and something might brake, you have a rest, and CLINK the taper joint snaps open - you sigh with relief.
Anthony
 

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#9 ·
Hi Guys
I'm new to this
How much play should there be in these ball joints?
I can move mine just enough to feel the movement with my hand
maybe 0.5mm
Should I change them?
It makes more sense to look at the mileage on the vehicle because unless you have MB service history or invoices for work carried out, it would be pretty safe to a assume they have never been changed. This job is something that appears straight forward but beware, the tool had to be modified correctly and requires going back and forth from the ball joint to an angle grinder and getting the angle perfect. A lot of cursing involved here :)

Also torquing the bolts is important, you must keep the suspension under compression when tightening any sus bolts, no good tightening them to a torque specification on axle stands (unless you have spare one to place under the control arm to jack the sus).

A long as you got the required tools, ball joints and patience then there is no reason this job couldn't be done in half a day. A lot of that time is spent modifying the tool, then seeing if it will fit, and so on.

I replaced mine with MB parts and as I've said in a previous post above, it's made the front end much more flat, predictable and much less under steer when pushing around corners. I recommend this job.
 
#8 ·
Nice tips, and I would add that if you are also doing your steering drag link (or just the tie rod ends) do that before modding the HF tool, as it fits and works perfectly, as is, on all four of the steering linkage ball joints. At first I thought there wasn't enough clearance for the inners, but you can turn the steering wheel and find the sweet spots. It helped to take the bolt and lever off to tap the forked half of the tool all the way onto the joint, then put the lever and bolt back on. While trying to sort out the inners, I also considered putting the bolt in upside down so the head would be pushing the lever out from between the two halves, but I repositioned the tool, got out from under the car, and found easier access by sitting at the side to turn the bolt head on top. Using a safety string and leaving the nuts right flush with the end of the ball joint bolts also worked a treat. The pop still made me jump, but the tool and joint stayed in the general vicinity. For big and small joints, I see Mercedes emphatically notes to clean the holes and the new ball joints of both debris and oil residue - don't try to lube the rubber to install, and don't over torque, or they slide in too far and pinch.
 
#11 · (Edited)
I just did mine today, took about an hour and a half. I used a ball joint removal tool that I bought off EBay, made for Mercedes. No grinding required. It ran $23.


This is how I did it;

1) Jack car, used jack stands and removed wheel.

2) Turn steering wheel to point rotor inboard to the max.

3) Remove horizontal (rearward/bottom) ball joint nut.

4) Us tool and BFH (big frigging hammer) to loosen ball joint tapered
shaft.

5) Use tool to remove tie rod end.

6) Support front rotor/caliper/hub assembly. (wire ties or coat hangar)

7) Use tool to loosen and drop assembly from upper ball joint. (This
allows free access to the lower ball joints upper bolt)

8) Rotate rotor/caliper/hub assembly to provide easy access to lower ball
joint top bolt.

9) Remove top bolt and used tool/BFH to loosen ball joint tapered shaft.

10) Remove old ball joint.

11) instal new ball joint into it's upper position, install nut and tightened
fully.

12) Reinstall upper ball joint and tie rod while sliding the new lower ball
joint's horizontal tapered shaft into the tapered spindle hole. Align ball
joint pin in hole. Tighten fully.

13) Install nut on the lower ball joint's tapered shaft and tighten fully.

14) reinstall/torque wheel to specs. Remove jack stands and drop car.
 
#12 ·
...
4) Us tool and BFG (big frigging hammer) to loosen ball joint tapered
shaft.
...
Young children?
Last time, a big frigging hammer was BFH.
:wink: :rolleyes:

Nice stripdown; a ball-joint separator like that works nicely with minimum damage to the joint rubbers, since although it may need a bit of help getting into place, you can then wind it to put pressure on the taper, and then ease the joint with a shock. (Show it a picture of BFG >:D)
The other design, the wedge, requires that the assembly is quite well held, and then provided with a clout from a BFH; getting room to swing, and the risk of damage to the joint rubbers are the drawbacks. (Yes, the joint you are replacing is not a problem, but you normally have to split a few joints :splif: when extracting the one you want to change, and you don't want collateral damage.
All down to the tools you can find; I have an old splitter that has thin edges, so gets in without damaging the rubber; similar to this one but thinner edges. In this case, cheap may not be good value, but it is whatever suits you.
 
#14 ·
I know this is an old thread and a sticky but I feel the need to add my experience of bottom ball joint replacement.

My car failed its MOT on the BBJ's and I managed to source replacement parts from GSF here in the UK. However, no amount of hammering or driving in ball joint splitters was going to help me. They were so badly worn that drastic action needed to be taken. I had to use a power file to grind away the nut in order to release the joint. It took ages but it was sucessful. Just my two penneth!
 
#15 ·
Thx for this thread! Replaced mine tonight without removing calipers. Took me 3 hours because I slow. Used a Schwaben Merc/BMW/Audi ball joint tool. Worked great. Only issue was when the passenger side upper bolt started spinning the shaft. had to modify a 5mm allen wrench to be short enough to fit in there to hold the shaft steady. Wasn't sure what the torque specs were. Tightened the top nut as much as I could as you can't fit a torque wrench there. Tightened the bottom to about 75 fl-lbs because that was close to some torque specs on some other Merc ball joint DIY's. Car steering definitely feels tighter.
 
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