Replacing upper control arm assemply... - Page 2 - PeachParts Mercedes-Benz Forum

BodhiBenz1987 · #16 04-01-2009, 01:14 AM

Is there any reason to replace both sides at once? My right-side UCA bushings are absolutely obliterated, but the left side bushings look just fine. Both upper ball joints look fine. I was going to replace the right-side UCA bushings and swaybar bushings. I don't particularly want to spend the money and time replacing the left side when it looks perfect, unless there's any benefit to that.

toomany MBZ · #17 04-01-2009, 01:33 AM

Quote:

Originally Posted by BodhiBenz1987

Is there any reason to replace both sides at once? My right-side UCA bushings are absolutely obliterated, but the left side bushings look just fine. Both upper ball joints look fine. I was going to replace the right-side UCA bushings and swaybar bushings. I don't particularly want to spend the money and time replacing the left side when it looks perfect, unless there's any benefit to that.

No problem replacing just one side.
When I did mine, the bushing was destroyed, ball joint was fine.

MercFan, keep searching the FSM, diagrams are in there.

MercFan · #18 04-04-2009, 11:21 AM

Quote:

Originally Posted by jt20

I might mention that the squeaking is not from the UCA ...

I took this clue and got under the car (passenger side) while a helper bounced the car up and down to reproduce the squeek. I located it in the sway bar bushing that fits in the body (barely visible from the wheel well). The noise is ONLY on the passenger side. For starters, I may shoot some WD40 in there to quiet it down. Thing that amazes me is that this rubber bushing looks really new to me... so question 1 is: is this bushing something pretty easy to replace? I'm guessing that if I take out the battery and its tray that it may be accessible under then?! Question 2: what's the part number and where do I but a replacement bushing - could not find anything on Fastlane that resembled that.. Thx in advance.

PS - I may replace the UCA anyway even though they aren't the source of the squeek, just because the outer bushings appear dry-rotted... it just means this project got quite a bit bigger...

toomany MBZ · #19 04-04-2009, 11:47 AM

Confirm the squeaky area in the pics, if you would.

MercFan · #20 04-04-2009, 12:18 PM

Quote:

Originally Posted by toomany MBZ

Confirm the squeaky area in the pics, if you would.

Well, I'm pretty sure it's the first pic with the red highlights around it (except on passenger side)... Since I did not have access to the other parts yet I can't confirm or deny...

I need to see if I can get under the battery before I can be sure - right now I'm betting it's the first picture and thanks for helping.

BodhiBenz1987 · #21 04-04-2009, 01:13 PM

Here is a diagram I got from EPC and labeled ... the swaybar isn't on it, but it goes through the round hole on the UCA, surrounded by #77 bushings. The vertical piece in this picture is the steering knuckle .. it did not have a # on it. Let me know if you can't read it and I can try to make it bigger.

BodhiBenz1987 · #22 04-04-2009, 01:29 PM

Another pic, which has the swaybar mounts and brackets that mount the car to the frame. The mount # is 123 323 05 85, brackets 123 323 01 04.

The number for the bushing that connect the swaybar to UCA (in my previous post) is 116 333 40 14 ... I have a couple sitting here I was hoping to install today, but the 40 mph winds have convinced me to wait.

tangofox007 · #23 04-04-2009, 01:35 PM

Quote:

Originally Posted by 83240D

I stand corrected as far as being able to replace the lower ball joint without a spring compressor. Tangofox07 did state however, that spring compression is not required for a W123, that is also incorrect. A person could not replace LCA bushings without spring compression.

Shipmate, if you are going to correct me, could you please do it within the context of the discussion? You were specifically talking about the lower ball joint, which has absolutely nothing to do with an LCA bushing.

To wit:

Quote:

Originally Posted by 83240D

Squeaking sounds like a lower ball joint. Replacing the lower one requires spring compression.

MercFan · #24 04-04-2009, 01:50 PM

Quote:

Originally Posted by BodhiBenz1987

The mount # is 123 323 05 85...

Thanks - that's it, I believe. Will just double-check later this week before I order it. Assuming that's the part - what's the steps of removing and re-installing... looks like it may be a tight sqeeze into that spot without some lubricant...

BodhiBenz1987 · #25 04-04-2009, 02:00 PM

While we're sharing, can someone do me the quick favor of telling me the torque spec for the bolt that holds the UCA to the frame? I don't have the FSM for this vehicle, and Haynes isn't as all-knowing. I have 48 ft/lb for the bolt on the end of the swaybar.

tangofox007 · #26 04-04-2009, 02:15 PM

UCA to frame bolt is 80 Nm.
Guide joint is 40 Nm.
Torsion bar bolt is 65 Nm.

Nm x 0.737 = ft/lbs.

BodhiBenz1987 · #27 04-04-2009, 04:52 PM

Quote:

Originally Posted by tangofox007

UCA to frame bolt is 80 Nm.
Guide joint is 40 Nm.
Torsion bar bolt is 65 Nm.

Nm x 0.737 = ft/lbs.

Thanks!

MercFan · #28 04-04-2009, 06:37 PM

Quote:

Originally Posted by toomany MBZ

Confirm the squeaky area in the pics, if you would.

I took the air filter housing off along with the battery this morning to get to the problem area. With the battery out, the sqeek is still most intense in this area (borrowing the picture) - but on the passenger side.

Noticed that this bushing is split so it looks like installing it should involve just taking off the bracket that holds it in place and 'wrapping' the bushing around the torsion bar?! hopefully no surprises there especially with the tension on the bar... not sure how that will playout but I'm sure I'll find out... Any other tips would be appreciated.

I guess, how do I take the tension off that bar - I'm assuming it's under tension while the wheels are on the ground... if I were to jack up both sides of the car and have the wheels just 'hanging' - would that relieve the tension or no?!

toomany MBZ · #29 04-05-2009, 04:28 AM

This is from the FSM.
First three...

toomany MBZ · #30 04-05-2009, 04:53 AM

Last three.
Somewhat involved. You may be able to change one mount out without removing the entire bar.

In pic #3 above at the top it says "remove tandem main cylinder and brake unit."

In the last pic here, #12 reads "slip rubber mount of torsion bar bearing on front wall on torsion bar, with separating slot toward the rear."