Lower Control Arm Project - PeachParts Mercedes-Benz Forum

byronnash · #1 03-11-2011, 12:34 AM

I finally rented vstech's spring compressor and got started on my lower control arm rebuild tonight. I have all the parts off the car and apart. I was not able to get the spring all the way out and didn't want to start banging it so I left it compressed and just sort of hanging up there. The only two things I can't get disassembled right now are the lower control arm bushing and the ball joint from the spindle. I threaded in the new guide rod mount and put in the new bushings that connect the guide rod to the LCA.

3 questions for the experts on here.

What's the easiest way to get the lower control arm bushings out of the end that is closest to the engine?
For those of you who have gotten the ball joints out of the spindle yourself, what tool did you use? I rented a set of tools from Advanced but haven't figured out how to get it out so far.
I think I may have damaged the threads on the UCA ball joint when popping it loose from the spindle(?). Did I just buy a new UCA or is there some way to fix that?

Thanks!

DeliveryValve · #2 03-11-2011, 12:48 AM

Quote:

Originally Posted by byronnash

I finally rented vstech's spring compressor and got started on my lower control arm rebuild tonight. I have all the parts off the car and apart. I was not able to get the spring all the way out and didn't want to start banging it so I left it compressed and just sort of hanging up there. The only two things I can't get disassembled right now are the lower control arm bushing and the ball joint from the spindle. I threaded in the new guide rod mount and put in the new bushings that connect the guide rod to the LCA.

3 questions for the experts on here.

What's the easiest way to get the lower control arm bushings out of the end that is closest to the engine?
For those of you who have gotten the ball joints out of the spindle yourself, what tool did you use? I rented a set of tools from Advanced but haven't figured out how to get it out so far.
I think I may have damaged the threads on the UCA ball joint when popping it loose from the spindle(?). Did I just buy a new UCA or is there some way to fix that?

Thanks!

What do you mean the spring is just hanging there? When you release the shock and upper control arm from the spindle, the spring should fall out with the compressor.

To remove the bushing from the control arm, you just cut/saw the sides of the bushing and punch them out.

To unhook the LCA from the spindle, I either wack it fork tool or get a big hammer and wack it hard as hard as I can at the LCA eye. When hitting it very hard, it will come apart.

If the UCA balljoint stud is mushroomed and threads are damaged, it's probably best to get a new UCA.

.

Stretch · #3 03-11-2011, 03:24 AM

Here's how I did my LCA:-

How I ended up fitting the bushings to my W123 300D LCA

With regards to the UCA - I'd just replace the whole thing - life is too short and they don't cost so much at the moment... I've kept my old one for when they reach unobtainium status! (I'll be waiting for a long time)

byronnash · #4 03-11-2011, 01:07 PM

See the photo below. It feels like the top of the spring is just really tight in the space. It's not in the way so far. The spring compressor only went through the hole up top under some pressure.

Stretch · #5 03-11-2011, 01:12 PM

Quote:

Originally Posted by byronnash

See the photo below. It feels like the top of the spring is just really tight in the space. It's not in the way so far. The spring compressor only went through the hole up top under some pressure.

I think you're probably using a comparatively cheap spring compressor - these tend to be wider at the top (the end that you attach a socket onto) and they can get stuck in the hole in the chassis...

Most people tend to file away a little bit of metal on this hole to make a clearance fit for the compressor.

Get a rubber hammer and very GENTLY tap the top of the compressor so that it falls below. CATCH THE SPRING! Don't let it drop - I don't want to read that the compressor failed and that you've now got a W123 front spring wedged in your nuts...

Diesel911 · #6 03-11-2011, 01:14 PM

Ball Joint Nightmare - chapter 2; you might want to read the complete thread the address below starts on page 2 of the thread.
Beating on the side of the Control Arm to release the Ball Joint from the Taper 2nd page
Ball Joint Nightmare - chapter 2

I have never tried the above mentioned method. If it works please post the results.

Somewhere in our DIY sedtion one of the members tested several tools to press The Ball Joint off the Sindle. One of the Tools that worked was one he already had. He called it a Pitman Arm Puller but the one he used is slightly smaller than a Pitman Arm Puller; often labled Tie Rod puller see Pic.

He said it fit well.

colincoon · #7 03-11-2011, 01:18 PM

Which side uca did you damage? I have an extra I will let go of for $30 bucks. It's the drivers side.

Diesel911 · #8 03-11-2011, 01:33 PM

DIY Repair Links
http://www.peachparts.com/shopforum/diy-links-parts-category/

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

byronnash · #9 03-11-2011, 01:39 PM

The UCA Ball Joint mushroomed because the puller I was using slipped and wasn't sitting right in the middle of the bolt. I guess I should have left the nut on there to prevent it.

I'll try that pitman arm puller to get the LCA ball joint out of the arm. It came out of the steering knuckle pretty easy with a fork.

1stbenznc · #10 03-11-2011, 02:19 PM

The threads can be fixed by retaping them. Rental from the Auto store.

If you can't but the whole control arm with new bushings and ball joint, like stated above, you really need to WORK on them to get them out. I had to actually tear/punch out the rubber center section, then carefully cut the side of the metal bushing with a hacksaw, THEN use a air hammer to get the damn thing out. It was a real bear!

See post #15 here.... 124 front control arm bushings and replacement....snag

Make sure the new bushing go in the correct orientation. and only tighten then when car is sitting back on the ground. I know on the w124's one mark goes vertical and the other horizontal. Hopefully you marked or took pictures of the orientation of the c-arm bolts and washers. An allignment will be in order after.

The spring compressor looked to be the correct MB tool . The spring is likely just stuck next to the bubber spring pad , wedged up in there. With some wiggling will fall out - catch it!

1stbenznc · #11 03-11-2011, 02:27 PM

Quote:

Originally Posted by 1stbenznc

Make sure the new bushing go in the correct orientation. and only tighten then when car is sitting back on the ground. I know on the w124's one mark goes vertical and the other horizontal. Hopefully you marked or took pictures of the orientation of the c-arm bolts and washers. An allignment will be in order after.

I forgot yours has only one LCA bushing

. The rest is applicable...

byronnash · #12 03-11-2011, 02:37 PM

I'm hoping I can retap or grind off just the corner of the stud where it got smushed. I just put that UCA on in October. Arggh.

An alignment is my first stop after I get this thing rolling again!

byronnash · #13 03-11-2011, 02:44 PM

I'm putting 126 inner bushings in per Roy's advice and it looks like they are easier to get in than the 123 ones.

Diesel911 · #14 03-11-2011, 05:52 PM

Quote:

Originally Posted by byronnash

The UCA Ball Joint mushroomed because the puller I was using slipped and wasn't sitting right in the middle of the bolt. I guess I should have left the nut on there to prevent it.

I'll try that pitman arm puller to get the LCA ball joint out of the arm. It came out of the steering knuckle pretty easy with a fork.

In the last sentence which It are you speaking of? Removing the Ball Joint from the LCA or removing the UCA Ball Joint from the Steering Knuckle/Spindel.

byronnash · #15 03-11-2011, 06:03 PM

I was referring to the LCA there. If I can't get the threads fixed on the UCA, I'll replace the whole thing.