Upper Control Arm Lower Ball Joint Front Brakes
 

I was going to replace my front brakes on a 1985 300SD. While looking around and seeing the rotted rubber covers on the ball joints, I decided to order parts for all those repairs. So, what is the process for doing all three repairs. I do not have the press for installing the lower ball joints. I will bring new lower ball joints and knuckles ? (or is it a control arm) to a local shop. Do I have to worry about the springs when doing this job. I have read about doing the three jobs as separate jobs, not all together. Am getting confused...

The shocks and the upper control arm keep the spring from opening up all the way. If you remove the steering knuckle and upper control arm, put a jack under the lower control arm to support it until you have the steering knuckle back in place with the upper control arm.

So, are you saying to do the upper control arm first, then go to another part of the repair list, perhaps lower ball joint and finally the rotors and new pads? I don't want to start on one thing and find that I should have done something else first!

If you are going to completely remove the steering knuckles and take them to a shop, it make no sense to do the UCA's separately. The entire job can be done at the same time if the weight of the car resets on the lower control arms.


The caliper and wheel hub/rotor have to be removed as part of the lower ball joint job. That's the perfect time to renew brake parts.

The important point is Safety!

When you dismantle the front suspension components like removing the UCA, the only thing left keeping the spring in place, is the shock-absorber...

These can and have broken....:eek:

The result can be rather nasty, as that spring can fly out of place and could seriously injure someone or something...

The way I did mine, was to raise car up, remove all brake-components, then place a large block of wood Under the LCA and allow some weight of the car to compress the spring an inch or so before removing the UCA and the steering 'knuckle'....

This makes sure that the spring doesnt place all its load on the shock-absorber....

Best way would be to use a proper spring-compressor to make sure the spring doesnt extend...
A heavy (1") thread passed through the spring and two substantial steel-plates can be used to secure the spring when removing LCA or UCA ball-joints from the steering knuckle........

It's Sunday morning, nice day out. I have parts on order and was thinking, while waiting for them, maybe I can tear-down one side or the other on my front end. I have jack stands and 2 floor jacks, so I could take everything off. I will hang the calipers on wire or rope. I can use my wifes car tomorrow, for my drive to work...

So what's first, remove caliper, rotor and hub, then separate upper control arm and then finally work on the lower ball joint? Or some other combination....

Yup, Its a nice sunny afternoon here in Welsh Wales too--Which is nice!
--Need to go out and strip some stuff off my old 300D parts car....:rolleyes:

Any combination is fine, but just make sure that spring Cannot escape!

Personally, I did it in this order.

Wheel, brake-pads then caliper, disc and wheel-bearing/hub assy, then steel back-plate...
(with back-plate, its secured by 5mm? Allen socket-bolts, They can be tight--Advise 'shocking' them with 5lb hammer before attempting removal....)

Steering linkage to steering knuckle, either the ball-pin or the two bolts...

Support spring...

Then UCA ball-joint..

Finally lower ball-joint.

Stub-axle (steering knuckle) is then free....

I took mine to a local MB place who has the correct tool to press in the bottom ball-joints as they require quite some force,--approx 5-10 tonnes....:eek:

Thanks for the "plan"

Do I have to remove the back plate? How do you "Shock" the Socket Bolts?

Is securing the spring with a floor jack sufficient? I have 2 of them.

For someone else who is comtemplating the same Job:

Even though the Ball Joint Boots are ripped it is possible for the Ball Joints to be OK.

There should be a way to test them in our DIY slection:
Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82

http://www.peachparts.com/Wikka/DoItYourSelf

When the Lower Control Arm bushing went bad on my own Car I orded a compete front suspension kit because I needed to get my Car running as soon as possible and did not want to wait on parts if I found something else wrong.

I did not check any of the Joints because I had the whole kit coming. But, what I found is that one of the Ball Joints was bad on one of the Upper Contol Arms was no good.
Since I already had the 2 new upper Control Arms I replaced both.

What also found is my Lower Ball Joints were OK but I had damaged the Boots separating the Knuckle from the Lower Control Arm.
Since they were still good reused the Lower Ball Joints planning at to change the Boots Later. I did get around to changing the Boot on one side; but still have not done the other.

In the Factory Service Manual and maybe in our DIY Section they have how to check the joints on the Car.

Place the jack stand under the LCAs, then lower the vehicle onto the jack stands. Depending on a jack for support is never a good idea.

It's hard to drive around with torn boots and not contaminate the joint. The FSM recommends that boots never be replaced independently unless they were torn during current maintenance.

A new OEM ball joint can be had for under $25. What does a new boot kit cost?

Update and details on the tryptic job. The upper control arm ball joints were bad on both sides. they made noise with tapping on the arms with the front end up off the ground. the lower ball joint on the right side was also sloppy.
driver side lower was good, but the boot was squashed and ripped all around the equator. rusty grease was seen in the drivers side lower...

When I drove the car as of yesterday, I always heard clunking sounds on the right side. and when brakes were applied there was a clatter on the right side, if I broke hard...

Pads were way worn. Just in time on the brake job!

Took everything off the car this afternoon. Had trouble with the nut on the upper control arm ball joint on the drivers side. It had to be cut and popped off the threads since it was stripped. It just kept turning while I tried to remove it. The ball joint was not moving as some may think. I was aware of the potential spinning, but was touching the bottom end of the "bolt" while turning the nut with a 17mm open end wrench. The nut was turning, but the bolt was NOT moving....

Seems like the worst part of the replacement job is going to be fitting the long bolt through the upper end of the upper control arm. Not much room under the wiper fluid tank or the drivers side area either... Any tricks for aligning that bolt through the bushings?

Also, the socket cap screws that hold the hub and rotor together seem to be tough to loosen. I might bring them to the local shop and have them open them up as well as press out the lower ball joints.

Should get parts tomorrow or Tuesday, so my commuter car will rest a few days. It has 342,000 miles on it. Exhaust system is next. Saw pin holes and soot on the pipes when the car was on a lift last week. Had a warranty issue with an altenator. The local shop was working on it and I was snooping around and saw the thick soot or carbon.

Will need to replace from manifold back to the muffler... Anything to know about exhaust replacement?

^ On the exhaust replacement, I provided the muffler and had a shop do the rest.

Reason I am asking about exhaust is because, when I was a young man, I had a horrible time with a honda accord swap out... swore i would never touch an exhaust system again.... That was in 1985 and i am now almost twice my age then, something tells me to stay away from that rusty group of metal objects.....

Totaled up the parts for a complete job and it's around $820.00

Not sure what the shop time is, any educated guesses out there?

what's in the 820.00 parts list?
there is a thread on here somewhere about piping in SS 3" tubing for about 200.00 i'd go that route...