DIY Bearing Bracket guide rod mount replacement for Mercedes Benz 300SD. - Page 3 - PeachParts Mercedes-Benz Forum

Brian Carlton · #31 08-06-2009, 04:58 PM

Quote:

Originally Posted by vegburner

Yes, I removed the back cover. Just to be clear, I'm talking about the front of the guide rod that bolts to the LCA. I just read that a spring compressor is needed.

Just tap upward on the nut while it's threaded on the end of the screw. Nothing holds the screw in place other than filth and corrosion.

I just did one yesterday...........no issues.

Yes, I'm making the assumption that the spring is removed. You can't get to that screw with the perch in place.

vegburner · #32 08-06-2009, 05:01 PM

Thanks.

I'll need to find a spring compressor now...

mopart2 · #33 04-19-2012, 11:46 PM

Hello guys,

I am in the middle of changing out the drivers side guide rod mount bushing (1985 300SD). I was able to remove the bracket bolts, but when I went to unscrew the bracket assembly from the guide rod itself, the bracket would not budge. I removed the guide rod clamp bolt completely and tried spreading the tube open slightly, but still nothing. I soaked it with penetrating lube multiple times and still cannot get it to move. The last thing I tired was two pipe wrenches, one holding the guide rod and the other on what is left of the hex flats. I also added a pipe for more leverage. Finally, I used a torch to heat up the guide rod and using the pipe wrenches I was able to get it to move 1/8 of a turn. The threads don't look too rusty and the other two bolts came right out. The car hasn't been in the new york salt very much by the looks of things also.

Am I missing something? Has anyone else experienced such trouble removing the bracket assembly from the car? (by the way, my guide rod bracket is threaded all the way to the guide rod on both sides?)

After running to the parts stores, I was able to rent a coil spring compressor which might allow me to remove the spring perch and remove the guide rod from the LCA. That's for tomorrow night I guess.

Any thoughts or suggestions from anyone?

I am at a lost and very frustrated. Any help is appreciated. Thanks.

whunter · #34 04-19-2012, 11:55 PM

Quote:

Originally Posted by mopart2

Hello guys,

I am in the middle of changing out the drivers side guide rod mount bushing (1985 300SD). I was able to remove the bracket bolts, but when I went to unscrew the bracket assembly from the guide rod itself, the bracket would not budge. I removed the guide rod clamp bolt completely and tried spreading the tube open slightly, but still nothing. I soaked it with penetrating lube multiple times and still cannot get it to move. The last thing I tired was two pipe wrenches, one holding the guide rod and the other on what is left of the hex flats. I also added a pipe for more leverage. Finally, I used a torch to heat up the guide rod and using the pipe wrenches I was able to get it to move 1/8 of a turn. The threads don't look too rusty and the other two bolts came right out. The car hasn't been in the new york salt very much by the looks of things also.

Am I missing something? Has anyone else experienced such trouble removing the bracket assembly from the car? (by the way, my guide rod bracket is threaded all the way to the guide rod on both sides?)

After running to the parts stores, I was able to rent a coil spring compressor which might allow me to remove the spring perch and remove the guide rod from the LCA. That's for tomorrow night I guess.

Any thoughts or suggestions from anyone?

I am at a lost and very frustrated. Any help is appreciated. Thanks.

If you used an oxygen acetylene torch with no luck, the only option is to replace the threaded tube.

.

mopart2 · #35 04-20-2012, 06:20 AM

Quote:

Originally Posted by whunter

If you used an oxygen acetylene torch with no luck, the only option is to replace the threaded tube.

.

It was just a handheld MAP gas torch. Thanks, that might be the only option.

I didn't see any mention of left hand threads in the DIY writeup, so I am assuming that they are regular threads?

mccauleybil · #36 04-20-2012, 09:16 AM

I found myself in exactly the same predicament 3 weeks ago. Eventually, I removed the guide rod from the lower control arm (using the correct spring compressor), and took the assembly to a local machine shop. Their use of the right gas, and a 48" breaker bar solved the issue. I asked them to run a tap through the threads before re assembly and they commented that the threads were fine. Their supposition is that the combination of age, salt, thread lock was the culprit that created the issue. I am convinced that the $25 I gave them for their work was well spent, as I too was ready to order a new rod post haste.

mespe · #37 07-13-2012, 10:40 AM

I'm in the process of replacing the this bearing bracket, or guide rod ball joint, or whatever ya wanna call it. Am I to believe that by pulling the lower control arm forward, the entire bearing bracket assembly can be spun, to install the guide rod ball joint threaded pin into the guide rod tube? Thus eliminating the need to remove the spring.

Brian Carlton · #38 07-13-2012, 10:48 AM

Quote:

Originally Posted by mespe

I'm in the process of replacing the this bearing bracket, or guide rod ball joint, or whatever ya wanna call it. Am I to believe that by pulling the lower control arm forward, the entire bearing bracket assembly can be spun, to install the guide rod ball joint threaded pin into the guide rod tube? Thus eliminating the need to remove the spring.

Presumably, you're referring to the W126?

On that chassis, it makes more sense to remove the entire aluminum carrier that holds the subframe bushings and guide rod ball joint. There are only two screws that secure it. Of course, in Cleveland, rust might enter into this discussion.

If you do remove it, there is no struggle with pulling the LCA forward to get the rod out of the joint. I believe you can simply rotate it as you have indicated. The only question I would have is whether there is sufficient clearance to the body for the rotation.

In my case, I removed the spring to replace the forward bushing and could simply rotate the guide rod itself.

mespe · #39 07-13-2012, 11:41 AM

Quote:

Originally Posted by Brian Carlton

Presumably, you're referring to the W126?

Yes

Quote:

Originally Posted by Brian Carlton

On that chassis, it makes more sense to remove the entire aluminum carrier that holds the subframe bushings and guide rod ball joint. There are only two screws that secure it. Of course, in Cleveland, rust might enter into this discussion.
?

That's whaqt I did, but having some questions/problems as you can see in the picture, the assembly doesn't want to turn. I don't know how much force I have to put on the lower control arm to move it forward to be able to spin on the assembly as far as I want to go.

Quote:

Originally Posted by Brian Carlton

If you do remove it, there is no struggle with pulling the LCA forward to get the rod out of the joint. I believe you can simply rotate it as you have indicated. The only question I would have is whether there is sufficient clearance to the body for the rotation.

?

That is my question. Do I need to turn the adjsutment as if I were adjusting the caster so many revolutions (yellow arrow), would be much easier to turn the whole assembly, but it hits at white arrow

Quote:

Originally Posted by Brian Carlton

In my case, I removed the spring to replace the forward bushing and could simply rotate the guide rod itself.

SD Blue · #40 07-13-2012, 11:46 AM

Take a look at the Bearing Mount, where it threads into the guide rod, and you will note flats for a wrench. You may need several doses of rust penetrant.

mespe · #41 07-13-2012, 11:52 AM

Quote:

Originally Posted by SD Blue

Take a look at the Bearing Mount, where it threads into the guide rod, and you will note flats for a wrench. You may need several doses of rust penetrant.

I am re-assembling. The old guide rod ball joint was loose and I unscrewed it with a 19mm I believe. But this new one is kind of tight. My concern is my muscles might ache after wrenching so long, well that, and is it OK to turn the ball joint that many times?

Brian Carlton · #42 07-13-2012, 12:05 PM

Quote:

Originally Posted by mespe

That is my question. Do I need to turn the adjsutment as if I were adjusting the caster so many revolutions (yellow arrow), would be much easier to turn the whole assembly, but it hits at white arrow

Yep, that was my fear with the aforementioned advice. You cannot rotate the bracket because the body interferes.

As Sam mentioned, you have no other option but to slowly wrench the stiff joint into the rod............unless you want to remove the spring..............

Welcome to the aching old men's club.

mespe · #43 07-13-2012, 12:17 PM

Quote:

Originally Posted by Brian Carlton

Yep, that was my fear with the aforementioned advice. You cannot rotate the bracket because the body interferes.

As Sam mentioned, you have no other option but to slowly wrench the stiff joint into the rod............unless you want to remove the spring..............

Welcome to the aching old men's club.

I was gonna answer my own question. But I spent more time moaning and dreading it than actual muscle ache points that it earned.

took about 2 minutes with a 19 mm to turn into place. After a few spins with the wrench, it got considerably easier to turn.

thanks

drinkypoo · #44 02-12-2013, 06:37 PM

Quote:

Originally Posted by micalk

I had thought the same thing. With as tight as the thread was, I would have expected some scrambling of the threads on the bolt if that were the case. But there was nothing. This is a long bolt with a coarse thread and it goes through two holes (one in the bracket bushing and one in the chassis). So the bolt is pretty much lined up for you once the parts are in place and the bolt goes through the chassis. I started the threads by hand which usually prevents cross-threading. The threads were clean when it was disassembled, none of the usual mess you get after cross-threading. And when I re-assembled there was no issue threading the bolt in the old nut.

I had the same problem using a Meyle replacement part. I'm about to do the other side and I'm not even going to try using the new hardware, I'm just using red thread locker. I had to drill and split the nuts on the new hardware to get them off. All the other hardware was correct. Oh yeah, and a post above says there's cap screws on the cross member, that might be the case on long wheelbase, but up to 1985 at least they are hex head (17mm IIRC.)

I wrote up the job, no pics of course. You CAN put one bolt on and then rotate the carrier around, it worked for me.
http://hyperlogos.org/blog/drink/Mercedes-Bushwhacking

I don't care what anyone says, the replacement carrier mounting hardware Meyle is currently shipping is out of spec. My hardware was absolutely hermetically clean (cleaned with brush and solvent) and it was absolutely not cross-threaded. Cost me ten bucks and a trip to the wreckers to get some pulls from another vehicle. Hooray for California, and no road salts.

whunter · #45 02-13-2013, 12:04 PM

Quote:

Originally Posted by drinkypoo

I had the same problem using a Mahle replacement part. I'm about to do the other side and I'm not even going to try using the new hardware, I'm just using red thread locker. I had to drill and split the nuts on the new hardware to get them off. All the other hardware was correct. Oh yeah, and a post above says there's cap screws on the cross member, that might be the case on long wheelbase, but up to 1985 at least they are hex head (17mm IIRC.)

I wrote up the job, no pics of course. You CAN put one bolt on and then rotate the carrier around, it worked for me.
Mercedes Bushwhacking | The Hyperlogos

I don't care what anyone says, the replacement carrier mounting hardware Mahle is currently shipping is out of spec. My hardware was absolutely hermetically clean (cleaned with brush and solvent) and it was absolutely not cross-threaded. Cost me ten bucks and a trip to the wreckers to get some pulls from another vehicle. Hooray for California, and no road salts.

I have stopped wasting my time arguing with the aftermarket manufacturers about this issue, they claim it does not exist.

My answer is to re-use the old hardware, buy new OE hardware from the dealer, or tap the new aftermarket nuts and use Loctite® (thread locker).

.