upper control arm bolt
 

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.:confused:

btw
 

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

UCA bolts
 

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?

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

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.

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

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.

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.

That may have made things worse. There is a steel sleeve in the center of the rubber bushing. The bolt is probably rusted to the steel sleeve. The heat most likely allowed the sleeve to break loose from the rubber. Now you won't be able to break the bolt loose by turning it.

i dont think it was going to come off anyway. I mean beating on it with a 3 lb maul didn't budge it. Anybody else been here feel free to chime in. It looks as though I'm heading for drilling the stud out, but don't really have any way to do that. This sucks.

This may sound like an awful idea but could you get a saws all in there and cut the UCA off or even the bolt on both sides of the UCA and just get a new one.

I recently had a frozen bolt on the LCA on my Honda. I rounded broke a ratchet, rounded the head of the bolt, and spent about 3 days drilling it out. I wish those @*$%&*$%s didn't design suspension bolts to seize.

I was able to get a grinder with a cutting wheel on half of the LCA/bolt connection. I wrapped everything with aluminum foil as a spark shield and cut half the bolt, in half lengthwise. Then I just wore out a bunch of drill bits drilling. Get the cobalt tipped Dewalt bits from Home Depot/Lowes. they did the best job for me.

Mine came right out, sorry to hear of your troubles, good luck.

3 days!!! DOH!

Just a standard metric bolt? Nothing special about it? I'm holding the sawzall right now, with an impish grin. :D

Suspension bolts are hardened, that's why it took me a while with the drill bits. The bits don't last terribly long. I did spend a day drilling before I decided to cut a part of the LCA/bolt, so that was a bit redundant. It was a bit difficult to drill up into the bolt.

I would imagine its a hardened bolt but you should be able to cut it, just use the correct blade for hardened metal. I had to drill out one of my lower ball joints on the steering knuckle and I just took my time AND used a good drill bit.

How about using a small hydraulic jack to "press" it out? Unfortunately, unless they were put in backwards last time, you'd have to push from the front towards the back and I can't think of much to push against.

Worse comes to worse, you might try getting at it from below. The UCA alloy is pretty soft, and you might be able to cut it off from around the bolt with a hacksaw, even by hand. That won't free the bolt directly, but it'll allow direct access to the stuck part of the assembly.

AlsoI'm curious (for future reference) if the bolt head could have been torqued off? Or is that pretty much impossible with these hardened bolts?

uote=patbob;1622172]How about using a small hydraulic jack to "press" it out? [qUnfortunately, unless they were put in backwards last time, you'd have to push from the front towards the back and I can't think of much to push against.

Worse comes to worse, you might try getting at it from below. The UCA alloy is pretty soft, and you might be able to cut it off from around the bolt with a hacksaw, even by hand. That won't free the bolt directly, but it'll allow direct access to the stuck part of the assembly.

AlsoI'm curious (for future reference) if the bolt head could have been torqued off? Or is that pretty much impossible with these hardened bolts?[/quote]


that bit about the hydraulic jack is genius. That may break it loose enough to get it the rest of the way out. If that doesn't work I have the sawzall. My feeling on torqueing the head off is that first the inner sleeve would break free from the surrounding bushing and/or sleeve and then just spin. It seems mercedes owners are divided into two distinct camps here, those whose bolts just slide out and those of us who have to fight them out. My car has never seen a salted road either. Weird.

so I just cut through the UCA to frame bolt with the sawzall. It took about 20 minutes, most of that time was spent trying to see what I was doing so I didn't cut through something other than the bolt. I cut from under the car between the bushing and the frame, and once the rear side was cut I pulled the UCA back and pinned it under the sway bar giving me freer access to the opposite side.

Now I just need to find a replacement bolt. Hopefully NAPA or somebody like that can hook me up, none of the online mercedes parts stores seem to carry that kind of hardware. BTW the drivers side UCA bolt slid right out. Thanks for the help and responses all.

Measure the other bolt, that may help in procuring another one.

Got it in my pocket. I'll post its size and type for future generations. Woo-Hoo is spot on.

OK this is now my problem as well :-(
 

So the day started real nice...bright sunshine and a forecast for more of the same all the way to Canada Day. Headed over to Bens Lover's hse and we started off with the UCA removal. Popped steering knuckle from UCA, unbolted swaybar bushing, took off cone and washer then found we could not remove the bushings from the swaybar. Never mind, lets do remove the bolts inside the engine bay.

Nut came off easy. The bolt tough, just spins and spins. Its not going to screw out. We went at it with everything we got. Doesn't even budge a hair!

Screw it. Lets do the tie-rods. One actually had a grease nipple on the end of the tie-rod! Anyway, changed them both out and then tried the UCA bolts again. No go. Still got the LCA ball joints to do. Geez. Tired and frustrated as hell. Packed everything up and drove home gingerly.

A dump truck burns on the highway. They close it for 4 hours. I'm stuck in the middle with no lunch, no water and no answers. I have the manual and quite a few printouts with me. I read them back to back and nowhere does it mention that this bolt can be a beatch.

Until I found this post. Yep its been a fun day. Any ideas?

Oh and Dan...thanks for being such a good-natured, even-tempered guy. It was great working with you :)

Hey anytime Zu!
We still have to figure out a way to remove the bolt from the UCA:o,If we are not successful with that,maybe your alignment specialist might surely be able to do that.Its very frustrating to fight with this since there is not much room to wiggle around the top:mad:.Those tie rods were a breeze to do but whats left is a head bashing one!
Hey Bob in Virginia,any ideas that we may not of thought about?:confused:
Keep us all posted.
Many regards to all
Dan Richmond BC

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.

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! :mad: Can't imagine what could be holding it in there??:confused: 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 :eek:

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 :o

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).