Replacing lower control arm bushings while still attached at the steering knuckle? - PeachParts Mercedes-Benz Forum

bodyart27 · #1 01-22-2007, 09:18 PM

I'm wondering if this is possible to do. I'm trying to avoid a major disassembly of the front end.

While researching how to rebuild some of the front end on a 126, I saw a picture of a pitman arm puller being used to push the bushing out of the lower contol arm after the end had been cut off with a saw (see pics). Makes me wonder if the puller cold push in the new bushing (at least the core), and the rest of the job (press in the caps) with a tool like this:

Search Harbor Frieght for: ITEM 38335-0VGA

I have the spring compressor to remove the spring and take the tension of the lower control arm, but I don't have the special tool to pop the ball joint at the steering knuckle.

Do you think it can be done without removing the entire arm?

PatricdeBoer · #2 01-22-2007, 10:05 PM

While physically possible, It is humanly damn near impossible to do withought pulling the arm. If you are already compressing the spring, you might as well spend 30 minutes popping the upper and lower ball joints and unbolting the track rod. You will save time if you just pull whole the arm.

bodyart27 · #3 01-22-2007, 10:34 PM

When I popped the upper control arm last time, it tore the bushing (must be better options than that tool aid brand popper). Since the upper control arm is brand new (and replacing that bolt under the master cylinder REALLY sucked, I was trying to avoid that hassle / risk.

I did find a SIR tool that advertises doing it on the car... scroll down on this link: http://www.********.com/brands/sirtools/mercedes.asp

and look for "M 0062 " "Metal Clad Bushing Press Kit:"

I like the quote "On The Car Application!!"

$150 though

bodyart27 · #4 01-22-2007, 11:09 PM

You can tell I have nothing better to do tonight than search the internet for tools.....

http://www.baumtools.com/mercedes_catalog_2006.pdf

(Page 36 of 54 in the suspension section)

Still looking for a price on this one...

MarkM · #5 01-22-2007, 11:11 PM

I was worried when you first said that you wanted to do LCA bushings while the LCA was on the car....thinking that you were not going too compress the spring!!! I was relieved to hear you have spring compressor, etc. I understand your concern about separating ball joints...I have never been able to separate ball joints without ruining them...of course, when I was doing the work, I was specifically replacing ball joints so it didnt matter.

Once LCA bushings are removed, pressing new ones in while the LCA was on the car would be a breeze...just put a little silicone grease on them and squeeze them in at the same time with a large bolt, nut and washers.

So the big problem is removing them.....in theory nothing complicated...no special tools, just bash each one from the inside to get them out....but to do this you need a solid surface to place surrounding part of the LCA onto in order to deliver severe blows to the bushings. If the LCA moves in any way, you cant deliver enough force to the bushings to get them out. I dont think you can remove them with a puller by pulling on the lip...nothing solid to grab onto. Here are a few ideas:

1. Maybe heat the surrounding part of the LCA to soften/burn the bushing

2. Position a massive block of steel under the car in just the correct position to place the LCA against so you can smash the bushings...maybe a huge bench vise with the jaws open just the right distance to place the rim of the LCA around the bushing against. Maybe a huge bench vise in combination with an anvil, or something similar (granite block)

...as I said, simple in theory, but not that easy to do, especially when you will be under the car and you may not be able to get full swings with a hammer to knock the bushings out.

I think you could remove the Upper control arm while attached to the steering knuckle. so your only concern will be lower ball joints. You may be better off replacing lower ball joints (rent the press tool). The ball joints are not expensive, and may be easier to do than time and effort needed to do LCA bushings while attached to the car. You have the spring compressor...why not just do the lower ball joints and be done.

Mark

SD Blue · #6 01-22-2007, 11:24 PM

When I did mine, there was a technique of separating the ball joint from the steering knuckle mentioned by Whunter (with photos) that worked like a champ. With a ball pien hammer placed against the side of the LCA, at the ball joint, strike the opposite side of the LCA and "ring" the joint.

I'll see if I can't find that post. Here it is......post#19:Ball Joint Nightmare - chapter 2

bodyart27 · #7 01-23-2007, 07:14 AM

That might be the cincher. I was looking at this job as what would be more expensive - the specialty ball popper tool for the knuckle end of the lower control arm or a specialty tool to do the LCA bushing while on the car.

http://www.samstagsales.com/mercedes.htm#suspension (look at the BMW3030 - that's the popper)

I have a 20 ton shop press now, so pressing in the bushings out of the car was not the issue. There is no rush on this job, so what I might do is get the bushings and see if I can free the control arm with the sledge technique. If so, should be down hill from there.

tangofox007 · #8 01-23-2007, 10:02 AM

Quote:

Originally Posted by bodyart27

When I popped the upper control arm last time, it tore the bushing (must be better options than that tool aid brand popper).

A tie rod puller will work well on the upper ball boint. MB sells replacement grease boots.

Hit Man X · #9 01-23-2007, 11:07 AM

If you need LCA bushings, you probably need ball joints and track (strut) rod bushings too. Why not just pull it and do it properly?

Old300D · #10 01-23-2007, 01:02 PM

I replaced my lower control arm bushings on my 240D without removing ball joints. It was easy...remove the springs with the compressor, drop the arm at the pivot, drill out the bushings, re-install them with a big C clamp, and reinstall the arm and the spring.

Easy.

bodyart27 · #11 01-23-2007, 04:07 PM

I ended up ordering the popper for the knuckle ball joint so I'll probably just take the whole Lower Control Arm off and using the shop press for the job.

That would leave only the ball joints at the knuckle as the only thing not replaced in my quest for the world's slowest front end rebuild.

I know the boot on the driver's side steering knuckle ball joint is split so it needs to be replaced at some point. I'm still researching that procedure, but it sounds like everyone's least favorite part to swap (getting it out and putting a new one in - sounds like special tools or take the steerling knuckle to the dealer and pay for it to be extracted and pressed in).