upper control arm bolt - PeachParts Mercedes-Benz Forum

ichbineinekrous · #1 09-15-2007, 03:17 PM

is stuck, won't turn at all and I can't get anything on it from the rear/ back of the car side to beat it out, just not enough room to work. Anybody come up with a solution when confronted with similar problems? I'm trying to get the new UCA's in as well as tie-rod ends, lower ball joints (which are already pressed in) wheel bearing and new rotors done this weekend. Stumped right out of the gate. Help.

ichbineinekrous · #2 09-15-2007, 03:18 PM

The bolt i'm having problems with is the inner UCA bolt, the one thats accessed from under the hood.

techguy512 · #3 09-15-2007, 03:26 PM

Mine came right out. Of course, I had the sway bars and bushings out, and the steering knuckle disconnected so the arm was just "floating" and I could maneuver it around so all the tension was removed from the UCA to frame bushings. Is your UCA completely free, or is stuff still bolted to it?

tangofox007 · #4 09-15-2007, 03:50 PM

Quote:

Originally Posted by ichbineinekrous

Stumped right out of the gate.

The rest of us might be a little less stumped if you told us what car you are working on!!!

ichbineinekrous · #5 09-15-2007, 04:26 PM

sorry...1985 300D. The sway bar end of the UCA is loose but still around the sway bar. I can move it a couple inches, prob can get it off the sway bar if that will help. Im going to the store to get another torch, just propane for heating purposes, that's all I can think of short of grinding the head off the bolt and beating it out from the front side. Its soaked down with deep creep right now. I've heard people refer to their own horror stories with this particular bolt, but no-one elaborated.

ichbineinekrous · #6 09-15-2007, 04:28 PM

and the steering knuckle is off the car...lets see what else can I neglect to mention...

TMAllison · #7 09-15-2007, 04:48 PM

Do you have the LCA jacked up to take up the tension created by the coil spring? The coil spring, uca and swaybar link are all interconnected it looks like.

ichbineinekrous · #8 09-15-2007, 06:14 PM

yes there's no load on the UCA. I just removed the front shock and coil spring. Its floating there. Heated both ends of the stud with a MAPP gas torch for 5 minutes, the bushings started to melt and smoke and I got the stud to break loose from whatever's inside, i.e. it now turns freely. But unfortunately it still won't come out. I've now taken the battery and battery tray out and a coolant line so I can get a clear shot with a hammer. Not happening. It won't budge.

mobetta · #9 06-29-2008, 07:26 PM

I'd say its sawzall time. Are you replacing the UCA's? or were you going to re-use them? if it spins, the bushing inside is prolly shot, too- allowing the bolt and sleeve to spin.

are you still driving the car at this time?

I'd say order in all your parts and cut the Beatch out of there.

on the sway to uca stuff- I used a ratcheting tie down wrapped around the bumper to pull the uca forward enough to gain access.

bgkast · #10 06-30-2008, 12:12 AM

It's not threaded inside the bushing is it? Cant you just tap it out with a hammer now that the nut is off?

zu! · #11 06-30-2008, 01:41 PM

Quote:

Originally Posted by bgkast

It's not threaded inside the bushing is it? Cant you just tap it out with a hammer now that the nut is off?

Man, we tried everything. Even my holding a drift and Dan swinging away at that bloody bolt with two hands and it didn't even budge a hair!

Can't imagine what could be holding it in there??

The bolt is loose, spins freely, the UCA is loose (detached from the swaybar and steering knuckle balljoint)...we just can't figure it out.

I'm worried that if we cut off the bolt end (not much room on the master cylinder side too), where does that leave us? We already know it doesn't move what if it gets stuck in there

On the other hand, I have to marvel at how mercedes made that part of the body so strong that repeat misses on the bolt doesn't even dent the metal much

patbob · #12 06-30-2008, 07:51 PM

Ouch.. I feel for you. Dealing with this can't be fun. Here's what you're facing..

Inside the bushing is a steel tube that the bolt goes through. When the bolt is tightened down, the body of the car clams on that tube. It used to be attached to the rubber of the bushing, and isn't supposed to detach, but it apparently did. The bolt isn't supposed to get stuck in the steel tube, but apparently it did that too.

I was lucky when I did mine and neither bolt was siezed, but as I see it, there's only two options left -- remove the bolt head (and threaded part?) by cutting it off so you can pull the UCA out, or get the tube unstuck off the bolt with a torch.

If I had a torch, I'd go that route -- the UCA alloy is very soft and, while there isn't much room under there to cut it off the bushing, you should be able to cut it off hand with a naked hacksaw blade if you can't use an appropriate power tool. That route seems like a lot less work than trying to cut the head (and maybe the threaded end too) off with a metal cutting blade on a power tool.

If you decide to cut the head off, make sure you'll have enough clearance to remove it once it's cut off. You don't want to cut it off from above, only to find you need to repeat the job from underneath because the tube won't shift far enough to let the stub ends out (as I recall, it won't, but check for yourself.. even I don't trust my memory very far these days).