Write up - Ball Joints & Lower Control Arm Bushings & Tool Review (PICS!) - PeachParts Mercedes-Benz Forum

bodyart27 · #1 02-13-2007, 09:40 PM

This is not intended to be a step-by-step guide on replacing the ball joints and lower control arm bushings. It is really a review of some of the tools and tips that can make the job easier as well as inform you of some pitfalls you’ll want to avoid. The effort to assemble this write-up is just payment back to the forum for all the knowledge and coaching this group provides – god knows I “steal shamelessly” off this forum . Also, props to pindelski.com – worth every penny and has a great front end rebuild pictorial.

I’m one of those folks that pour over the forum, the internet and shop manuals to make sure I know what I’m getting into before I tackle a job. Without the aforementioned resources, I wouldn’t have dreamed of tackling rebuilding the front end of my 84 300SD. To bring you up to date on the rebuild, I’ve done upper control arms and sway bushings, an idle arm rebuild kit, the tie rods (about a year ago), and both ends of the brake / guide rod (piece on the lower control arm and the adjustable end piece), and the carrier support bushings as well. So, that leaves only the lower control arm bushings and the ball joints. Search the forum and you’ll find the install of a rebuilt steering box that I did about two years ago. When I started this part of the job (ball joints and lower control arm bushings) I did have one ball boot that is torn (but not dry). You’ll see that one in the pics. The other looked OK but will get replaced as well (it can’t be far behind).

First thing you have to have for a front end rebuild is a press. I picked up this monster Arcan 20 ton shop press from my local Northern Tool store. I think it was $330, but it is MUCH beefier than their $250 20 ton press (the piston is about twice as large for example). Notice in the pic that the press is flanked by Berd Schneider in a CLK DTM racer and Kimi Raikkonen in a McLaren …. but I digress.

Though the Tool Aid ball joint popper is cheap and popular on this forum, it also has a tendency (in my experience) to damage the boot on the joints. Additionally when popping one the joint on the upper control arms it wanted to rotate as I cranked down on the pin – not reassuring under that much stress! Since the upper control arms had been replaced about a month ago, the last thing I wanted to do was damage that boot and have to replace these parts again (pretty pricey parts and very difficult to get to the bolt on the driver’s side under the brake reservoir).

In my quest for a better ball joint popper, I purchased three alternatives from seller “Kinetik Auto Equipment Tools” on eBay. Two models have an arm extending which I thought might be nice as it would provide a counter hold, and thus prevent the rotation I experienced with the Tool Aid popper. They are offered in a 17mm gap and 20mm gap. I found the larger gap to be a close fit on the upper control arm, but I actually ended up using the JTC popper 1916 without the arm. What I liked about this design is that you can spin the tool and adjust the gap (the fulcrum bolt is threaded). It also seemed to “fit” the best on the upper control arm – just a little wiggling and it seats under the boot yet cups the arm well to prevent rotation.

PIC 1 - Aracan Press
PIC 2 - Assortment of "poppers" (black cone is the BMW 3030, long box along bottom is the ball joint tool, across top row in silver - JTC 1916, and the 17mm and 20mm Kinetik poppers with the handles)
PIC 3 - closeup of JTC popper
PIC 4 - demo of spinning fulcrum to increase / decrease gap

bodyart27 · #2 02-13-2007, 09:45 PM

Many people have used the “BMW 3030” tool by SIR to pop the lower control arm from the steering knuckle ball joint with success – but how? I could not get the cup of the tool around the end of the lower control arm. The gap on the tool’s cup was too narrow to slide over the end of the lower control arm, preventing me to get a safe perpendicular press on the ball joint. Instead, after a small panic and rifling through my tool chest, I found that my S-K brand pitman arm puller (#92506?) fit perfectly and made short work of the ball joint. I had the lower control arm and steering knuckle out of the car so I could have plenty of room to work.

PIC 1 - JTC popper in action on upper control arm
PIC 2 - SK Pitman arm puller to separate lower control arm from steering knuckle
PIC 3 - busted boot on ball joint
PIC 4 - kinda scary with everything is disconnected

vstech · #3 02-13-2007, 09:48 PM

I can't wait to rebuild my TD!
John

bodyart27 · #4 02-13-2007, 09:50 PM

OK – so the real reason for the write up. Just how good is the $89 JTC ball joint tool JTC #1849 versus the MB Tool / or generic design of the MB Tool ($300+)? I have not tried the MB Tool but I have ZERO complaints using this $89 flavor. The quality was much better than I had anticipated. As you probably know, there are a TON of crap tools coming out of China (much made with cheap steel). I’m not sure where JTC is made, maybe someone can look at the pics and tell by the script on the instruction sheet, but this piece is quality. The instructions are generic and in a foreign language, but luckily the pictures tell you everything you need to know. The ball joint is to be hammered out using the mandrel, and the ball joint pressed in using the cylinder tool. That is pretty much what the sheet tells you.

The mandrel, as you can see from the pics, fits well over the bottom of the ball joint. Not sure if you can tell from the pic, but I have the top of the spindle resting on two blocks of wood, then a moving blanket to protect my nice coated garage floor. A couple of good whacks with the sledge and you can see in the pic that the ball joint is starting to move. More sledge hammer whacks and it’s free.

PIC 1 - tool out of the box
PIC 2 - the adapter at the base - for 123?
PIC 3 - mandrel set ready to whack the ball joint out
PIC 4 - another mandrel shot

TheDon · #5 02-13-2007, 09:52 PM

that tools is good to have.. the tool we made collapsed under the pressure (same thing as the official tool but we made it out of some pipe)

bodyart27 · #6 02-13-2007, 10:00 PM

In order not to damage the boot on the new ball joint, I removed it before test fitting it in the tool. A small flat screwdriver helps move the retaining ring up so you can slip the boot off. Slipping the boot back on without getting grease everywhere is a bit more challenging. What worked was slipping the boot all the way on without the ring, then work the ring slowly down (again – a little challenging with the ball joint in the knuckle).

When Rashakor was over the following weekend, we found that you could actually keep the boot on, and the tool did not come in contact with the boot whatsoever – so, we left it on the second time.

As I was test fitting the ball joint, I realized there is an adapter being held in place at the bottom that needs to be removed (must be for another MB model – 123?). Hopefully you can see in the pic the o-ring on the adapter that was holding it in place – a nice design touch! With the adapter out, my 126 ball joint fit perfectly. The cylinder is resting on the outer ring of the ball joint, and the ball itself sits safely inside devoid of any contact (the concern here is that you don’t want any contact on the ball – which could mare the finish and reduce its life).

You place the base ring under the knuckle to true up and align the bottom and keep the knuckle off the press plates. That permits the perpendicular angle you need so the upper arm of the steering knuckle tucks into the slot of the tool’s cylinder. The upper part of the steering knuckle (the arm that connects to the upper ball joint) just floats inside the cylinder – it does not touch the inside wall of the cylinder. I did a quick check with a level to make sure the ball joint would be pressed in straight – everything lined up well without any fuss.

PIC 1 - ball joint starting to move
PIC 2 - ball joint out
PIC 3 - removing boot of ball joint (not really needed with this tool)
PIC 4 - steering knuckle resting on base

bodyart27 · #7 02-13-2007, 10:03 PM

JTC-1849 BALL JOINT INSTALLER

After that it’s a matter of letting the press do its thing – squish, squish, squish – and you’re done! I honestly can’t say anything bad about the tool – it worked as well as I could have wished.

PIC 1 - looking inside the barrell of the tool - no contact on ball joint
PIC 2 - ball joint press pretty much set up
PIC 3 - quick align check
PIC 4 - arm tucked inside tool

bodyart27 · #8 02-13-2007, 10:05 PM

JTC-1849 BALL JOINT INSTALLER

PIC 1 & 2: Squish Squish Squish....
PIC 3 - new Ball Joint in!
PIC 4 - ball joint with boot off (sorry this pic is out of order - but kinda neat to see)

bodyart27 · #9 02-13-2007, 10:13 PM

In comparison, I thought replacing the bushings on the lower control arm was more difficult of a job. I used a reciprocating saw to slice the cap off the control arm. I then used another S-K puller (4”) with some washers to push out the center bushing. That worked pretty well the first time. I’ll call this the pindelski.com technique, as that is where I learned that trick. The second time around I cut off both ends (Rashakor thinks very logically and two brains work faster than one) and just used the press (much easier). As you will see from the pic, the first time I cut the end off, I did not cut close enough to the control arm, and sliced through the cap’s metal. If you can slice close enough to the control arm so you get past the pressed on cap and expose just the cylinder that runs through the center of the control arm, then you can use the press on the cylinder to drive out the inner cylinder and the cap off the other side. There was a receiver in the Harbor Frieght Master Ball kit that cradled the arm and still had enough room to allow the bushing to press out (hope that made some sense – I know, a pic would have helped).

Remember to install the lower control arm bushings with the flats of the bushing in parallel with the control arm (just stop and think for a second what type of motion the inner bushing is trying to prevent on that side of the control arm – the arm being yanked in and out of the chassis mount).

PIC 1 - cutting the cap off the lower control arm bushing with the recipricating saw
PIC 2 - inside bushing exposed - I needed to cut closer in to the arm - you can barely see the two tones of metal - inner cylinder and the cap
PIC 3 - using a 4" SK puller - I didn't cut close enough past the cap for this method to work (worked on one arm, not the second). I'll end up cutting off the cap closer to expose the cylinder on the other side and using the press.
PIC 4 - holding up the inner bushing next to a new bushing installed. Notice how the cylinder extends past the ends of the lower control arm - ideally you want to cut the caps off to expose that cylinder. Also notice how much the caps crush down in size.

bodyart27 · #10 02-13-2007, 10:14 PM

PIC 1 - trying to explain the steps on the lower control arm (I should have taken more pictures... sorry)
PIC 2 - Baum / Klann Spring compressor (just because it's cool) - plates in place
PIC 3 - spring compressed

bodyart27 · #11 02-13-2007, 10:19 PM

Now for some of things I did wrong on this job – perhaps you can learn from my mistakes. Take the brake caliper and rotor off before disconnecting the lower control arm and guide rod. With the spindle dangling from the upper control arm it’s difficult to stabilize the knuckle to have leverage to free the brake caliper bolts. I had to loosely reattach the tie rod to get the leverage I needed.

Also, I unnecessarily panicked while pressing the lower control arm bushings in. I had a Master Ball Joint kit from Harbor Freight, which has a cylinder that is pretty close to optimal (just a hair to large – but did the job) to press on the ring of the caps that goes flush against the lower control arm once pressed in. While pressing the opposite side cap on, I thought I had deformed the other cap and started over with a new lower control arm bushing that was intended for the other side. That was a drag because I had to remove the bushing I had just pressed in (cut off end of cap and use a puller to push bushing out). I spent a horrifically long time with the press being careful not to deform the caps on the second set only to realize later test fitting the lower control arm back in the car that I that I had in fact not deformed the caps earlier as I had suspected. The caps did indeed need to be crushed further and should touch the cylinder that runs inside the inner bushing (I know, pics really would help). If you don’t crush the caps until the inner bushing’s cylinder is flush with the outside plate of the cap, they protrude too far off the ends of the control arm and won’t fit back on the car. Doh! Experience comes with practice I guess. That ordeal was a HUGE time waster.

Another gotcha occurred during reassembly when bolting the lower control arm to the new ball joint in the steering knuckle. As I started tightening the nut, the whole ball joint started spinning. There is not slot on the spindle or a hex key opening on the top of the spindle to apply a counter hold. Eventually after staring at the problem for 30 min (I was exhausted at this point), I realized that if I installed the spring and carefully lowered the car with the wheels turned (as the brake caliper was suspended from the sway bar), the spring would press the lower control arm down and the tire on the ground with the weight of the car would push the steering knuckle / ball joint up, preventing rotation of the ball joint and making tightening the nut a snap. Something to note, unless your arm is calibrated for tightening torque, “Kinetik Auto Equipment Tools” on eBay also offers a 22mm crows foot, which would allow you to use a torque wrench on that ball joint nut. At the time, the largest crows foot I had was a 19mm. So I had to use an open end 22mm wrench. I’m just that way – I like to torque everything possible to spec. So plan ahead!

Last gotcha. There are these crazy small bolts that hold the bottom of the shock to the lower control arm (requires a 10mm 12pt socket – 6 point won’t work). Of the two bolts, the inside bolt will not want to line up with the lower control arm dropped because the strut leans in at an angle, covering the bolt hole. The angle prevents getting a socket in there square and you risk damaging the bolt. Assuming you have not put the spring back in the perch, you can make the angle on this bolt better by placing a floor jack under the lower control arm and lifting it up and thus compressing the shock. I always start my nuts and bolts by hand and I could not get the bolt started. The problem was a bunch of old blue Loctite and some dull threads – not a winning combo when trying to start a tiny bolt. After some carb cleaner and running a tap and die through the bolt hole and bolt – it went in like butter . You might just buy new bolts – they would be cheaper than a tap and die set. Of course, that further delayed reassembly. If there was a perfect tool for that little bolt I’d recommend the SK ¼ metric 12 point flex socket set #1336. A set is not cheap at $100-$110 on eBay. FYI - eBay store seller “CBM Tools” is one of my favorite S-K tool dealers – good prices, fast shipping.

Just doing one side took me ALL day (good 10 hours). Granted I was taking some pictures, testing different tools, learning as I went, had some obstacles to overcome (mostly due to ignorance – I’m not a veteran mechanic and this is my first “rebuild”). The second time around when Rashakor came over to see how it was done, I had the other side done in about 4 and a half hours. Once you know what you are doing it goes a lot faster. Also know this is a lot of physical work. I’m in decent shape for a 38 year old, and I was sore as hell the next day after that first long day. Being a mechanic is tough on the body – my hat goes off to them. There is great satisfaction learning how do stuff yourself, and usually the labor savings alone pays for any tools you might need, but pick you battles!

.

PIC 1 - tight angle on strut & lower control arm - shows 12 pt flex socket vs regular 1/4" 10mm
PIC 2 - flex socket in action

guage · #12 02-13-2007, 11:20 PM

If you take off the two top nuts of the shock and compress it down through the fender you then can tilt it to reach the inner bolt head

PatricdeBoer · #13 02-13-2007, 11:28 PM

Awesome write up! You just motivated me to do my ball joints now! They're getting kinda sloppy with 310,000 miles of wear.

SD Blue · #14 02-13-2007, 11:56 PM

Great write up BodyArt!
Rather than a press, I used some 5/16" all-thread with nuts and several washers and 3/4 drive sockets for bushing presses. Took a bit of oomf but worked fine.

Hit Man X · #15 02-14-2007, 12:45 AM

Few questions:

Total shell out was what, about $400 for the press (20 ton and the long shaft joint one). Think funds would have been spent better on the "Official" MB tool? Remember, I have a 123 and a 116 to do in addition to my 126s... Looks like the cost of that MB tool is about $350 now and since I need a spring compressor I may as well order both at same time to drop shipping.

If so, would a 6-10 ton press work fine for the LCA bushings?