Lower control arm bushing replacement opinions

[JHZR2]

Moment of truth. Either I put the guide rod bushings back in and put the car back together, or attack the LCA bushing. I started taking things apart to do the job, but realized when the bushing relaxed it did t look that bad. 1991 Mercedes 350sd with 207k miles.

When they’re a bit more stressed due to the positioning of the guide rod, shock, spring, etc. they show more cracks.

Especially this last photo is the reason I’m considering replacement. Pressing these in and out is a pain. But so is removing the spring and separating the suspension again in the future.

So it’s a balancing act. This is a hobby. But I don’t want to take apart suspensions often especially to this level. Which would be reason to do it.

But when I let it be, just leaving the control arm up there disconnected from everything else it looks good and feels fine. Which makes be second think doing it.

@Trav and @Astro14 do you have any thoughts on this one?

 

[Kira]

How does it drive?
What vehicle?

 

[JHZR2]

How does it drive?
What vehicle?

Drives fine. 1991 mb 350sd with 207k. Had some clunking when braking due to the guide rod mount, which made me pull the spring and take stuff apart.

The fact that I have everything apart, and there’s slight cracking is the only reason I’m entertaining it.

@The Critic tells me much newer bushings on newer cars show slight cracking, so I may not have much to worry about.

It’s mainly doing the same bigger riskier jobs like spring compression, twice, versus doing everything while in there.

 

[slacktide_bitog]

This is a W126, right?

Delphi control arms are under $40 from Rock Auto. They are made in Turkey and probably from Disa.

 

[Kira]

It's Deeza, no?

 

[JHZR2]

This is a W126, right?

Delphi control arms are under $40 from Rock Auto. They are made in Turkey and probably from Disa.

It is. No interest in that. I have Lemfoerder bushings. The question is if they really need to be replaced.

 

[JHZR2]

This is a W126, right?

Delphi control arms are under $40 from Rock Auto. They are made in Turkey and probably from Disa.

Btw. If this is what you’re looking at, it’s not the part.

I don’t see any lower control arms on there. Bushings or not.

The uppers are a replacement part.

 

[Astro14]

It looks bad when flexed/unloaded because there are cracks. Those cracks don’t disappear when you load the suspension up and reduce the flex. They’re still there, but you can’t see them.

So, I would replace those bushings. Maybe not today, but sometime soon.

 

[JHZR2]

It looks bad when flexed/unloaded because there are cracks. Those cracks don’t disappear when you load the suspension up and reduce the flex. They’re still there, but you can’t see them.

So, I would replace those bushings. Maybe not today, but sometime soon.

They disappear when the whole LCA is unloaded. They’re definitely there when the suspension is loaded.

“Sometime soon” means today. I don’t want to have to pull the spring and everything again for a long time. Plus I need to do the other side. Only so many hours in a year….

 

[Trav]

I would do it today, those are dried out and wont last much longer. It may be a pain but with the springs already out you are more than half way home.

 

[Wrenchturner44]

I would do it today, those are dried out and wont last much longer. It may be a pain but with the springs already out you are more than half way home.

I second this vote. Plus with me, I would keep thinking about them if I didnt replace them.

 

[JHZR2]

I would do it today, those are dried out and wont last much longer. It may be a pain but with the springs already out you are more than half way home.

What a beast to get out. It was the original.

Pushing back in with a threaded rod tool looks even worse. Ovoid bushing in a curcular hole…

 

[UG_Passat]

All that labor to replace a bushing to save a few bucks, it would have been easier to just replace the entire control arm.

 

[Astro14]

What a beast to get out. It was the original.

View attachment 161875View attachment 161876

Pushing back in with a threaded rod tool looks even worse. Ovoid bushing in a curcular hole…

View attachment 161877

I’ve never seen an oval bushing intended for a round hole. That’s going to be a challenge…

 

[Astro14]

All that labor to replace a bushing to save a few bucks, it would have been easier to just replace the entire control arm.

You certain? A lot of junk parts for Mercedes out there. An actual Mercedes control arm won’t be cheap.

I would’ve done just the bushing, too.

 

[The Critic]

I’ve never seen an oval bushing intended for a round hole. That’s going to be a challenge…

That’s what I was telling him earlier - that type of bushing can be extremely difficult to r/r, even with the special tool.

I once ran into this issue in another application. After a few failed attempts I just purchased a new arm.

 

[JHZR2]

All that labor to replace a bushing to save a few bucks, it would have been easier to just replace the entire control arm.

You’re assuming the LCA is actually available.

You certain? A lot of junk parts for Mercedes out there. An actual Mercedes control arm won’t be cheap.

I would’ve done just the bushing, too.

Agreed. The FSM shows this is the way. The thing I didn’t have was a countersink big enough; which is how the FSM says to get through the one side in order to drive out the other. Something to remember for the opposite side.

That’s what I was telling him earlier - that type of bushing can be extremely difficult to r/r, even with the special tool.

I once ran into this issue in another application. After a few failed attempts I just purchased a new arm.

I’m not sure new arms are available. FSM goes through how to do it.

I don’t know why it is supposed to be like that. FSM shows it.

It did bunch up when pressing in with the tool.

But it went in.

The tool did get caught on the caps of the bushing.

Had to almost damage the tool.

 

[UG_Passat]

You certain? A lot of junk parts for Mercedes out there. An actual Mercedes control arm won’t be cheap.

I would’ve done just the bushing, too.

You buy from a trusted supplier. Not the usual things from Moog, Mevotech, etc

 

[JHZR2]

You buy from a trusted supplier. Not the usual things from Moog, Mevotech, etc

Even the good suppliers like Lemfoerder are now offshoring to Poland or Malaysia. More stuff isn’t available unless some vendor like Uro or Meyle reproduce it. Some are trying to do a good job. Some just have junk.

Dubious the actual control arm is available anymore, especially since the Factory indicates that bushing replacement is the correct refurbishment process.

 

[BMW Dom]

I would have just done the bushing

No sense replacing the whole thing if not needed

I'm about to press the bushings out of my upper control arm Wednesday