Guide Rod Mount Stuck - PeachParts Mercedes-Benz Forum

outofspec · #1 06-30-2018, 08:59 PM

W126 Chassis.

The bracket is out of the car, back plate and rod removed. The old mount is seized to the bracket. Currently trying PB Blaster and a BFH to bang it out. It’s good and stuck. Any ideas? Should I apply some heat to that aluminum bracket?
Thanks for the help.

Jorn · #2 06-30-2018, 10:24 PM

Quote:

Originally Posted by outofspec

W126 Chassis.

The bracket is out of the car, back plate and rod removed. The old mount is seized to the bracket. Currently trying PB Blaster and a BFH to bang it out. It’s good and stuck. Any ideas? Should I apply some heat to that aluminum bracket?
Thanks for the help.

Lots of BP blaster and I pounded it, between two 4x4's on the ground, with a large hammer, eventually it will come out. If I recall correctly, you should not press them in, but hammer them in when you reinstall the new ones.

outofspec · #3 06-30-2018, 11:37 PM

Thanks Jorn; I’ll get a bigger hammer and swing away.

Hit Man X · #4 07-01-2018, 12:46 PM

Before installing the new, clean out any rust/scale from that hole. I think I also lube mine with antiseize upon install. Remember, they need to be installed a certain way for water drainage.

outofspec · #5 07-02-2018, 11:13 AM

Like an idiot I've got the same kind of thread in the diesel section; but I'll post this here too, and close out the thread.
It's out, and the new mount / bushing is in. Lot's a PB, a big hammer, and a little heat from a propane torch finally freed it up. Thanks for the help guys.

In the DIY for this procedure, somebody mentioned that you should check the capture nuts for the bracket, and they were SO right. I don't know who designed them, but they are worthless. The exit side of the nut has no threads and wont let the bolt pass. I didn't have the right tap, so I had to use the old nuts. I wish I could buy that guy a beer as he saved me an afternoon trying to get that mess apart after inevitably spinning the bolt. It was a Lemforder kit.

Also, the Myele upper control arm I had for the passenger side had the bushing about 3mm wider than the OEM. Too wide to go into the body mount. The Myele arm for the other side was correct. I don't have a press, so I couldn't try to fix it; really tiered of parts that don't fit.

Jorn · #6 07-02-2018, 01:36 PM

It was one of the first "bigger" jobs when I got my 300SE, I remember it as no fun. The capture nuts are a horrible design, I had to saw one off the old ones as it was broken and the new one I broke again when I reinstalled it. Used Lemforder as well. Kent Bergsma sells a modified set, that has some extra weld points.

Hit Man X · #7 07-02-2018, 05:50 PM

Best part of the guide rod job?

NO CLUNK over bumps after.

outofspec · #8 07-02-2018, 11:45 PM

Well, my last post was at the conclusion of the passenger side. Today I tore into the drivers side and both capture nuts broke lose in the rust. Bolts with washers at the dealer now list for $98 each. 4 hours later I cut one bolt In frustration and I’m soaking the other one overnight and have drilled a hole in the frame to try and pin the nut. A nightmare of a job.
Jorn, how did you get a saw in that nut hole?

Jorn · #9 07-03-2018, 12:29 AM

Quote:

Originally Posted by outofspec

Well, my last post was at the conclusion of the passenger side. Today I tore into the drivers side and both capture nuts broke lose in the rust. Bolts with washers at the dealer now list for $98 each. 4 hours later I cut one bolt In frustration and I’m soaking the other one overnight and have drilled a hole in the frame to try and pin the nut. A nightmare of a job.
Jorn, how did you get a saw in that nut hole?

That sucks! I wedged the nut with a large screw driver and a thin long noised vice grip and used the thinnest blade I could find, without the holder/grip. That way I was able to loosen the bolt enough to create just enough room between the service and the nut to put the blade between it and cut it off. It was a hell of a job. I believe I still have a nut if you need one.

outofspec · #10 07-03-2018, 10:29 PM

That’s a good solution Jorn. I struggled with the bolts all day and finally got them out by drilling the nut virtually in half, and then splitting it with a small chisel. I enlarged the factory frame hole a bit, and it cost me two new bolts, but I’m glad that’s over with. I’ll install tomorrow. I bought new capture nuts from the dealer and they are every bit as tight as the Lemforder I’m a little nervous about driving those bolts home and busting of the new capture nuts in the process. Any experience here.

Hit Man X · #11 07-03-2018, 10:45 PM

You mean those four bolts that retain the rear cover?

Jorn · #12 07-03-2018, 11:25 PM

Quote:

Originally Posted by outofspec

That’s a good solution Jorn. I struggled with the bolts all day and finally got them out by drilling the nut virtually in half, and then splitting it with a small chisel. I enlarged the factory frame hole a bit, and it cost me two new bolts, but I’m glad that’s over with. I’ll install tomorrow. I bought new capture nuts from the dealer and they are every bit as tight as the Lemforder I’m a little nervous about driving those bolts home and busting of the new capture nuts in the process. Any experience here.

This is just an idea. What if you use a little bit of JB weld around the nut to the bracket to make it stronger. Hope this makes sense.

And make sure you treat the metal with some rust proofing where you made the whole larger, they can rust out badly quick.

The image I found from another PP member, it shows the problem.

Hit Man X · #13 07-04-2018, 10:42 AM

I have had same problem too on piles of those sets, I just toss those and use the OEM hardware. It is as if the thread pitch and count do not jive.

outofspec · #14 07-04-2018, 04:20 PM

Hey fellas, thanks for the tips.
Hit Man; I was talking about the capture nuts on those metal tabs that insert into the frame and retain the bolts for the guide rod bracket. Jorn has the picture.
Treated the enlarged holes, thanks for the reminder. I ended up useing the Capture nuts I got new from the dealer. They look a little sturdier than the Lemforder ones, but maybe that’s just in my head. Anyway, they worked without issue, and without modifications. I used a steady pressure with an air ratchet, and I used a filler behind the bolt head and the bottom of the socket so as to exert upward pressure on the capture nut throughout the tightening. I think jerking the bolt in with a ratchet, and no upward pressure against the nut may add to the failure problem.
Thankfully, it’s all done. Did the lower ball joints and shocks at the same time. The creaks and groans are gone. The 1990 daily driver is back in action.
Thanks for the tips, and support fellas. It’s good having guys around that appreciate these old cars and what it takes to keep them running.

Hit Man X · #15 07-04-2018, 05:16 PM

First time you do a W126 front end it takes a while. After that, it is faster and faster. I think I can have it all out in about three or four hours now! Rebuild depends on the severity of clapped outness up there. The LCA bushings are the absolute worst to do.