A job I was dreading since my "shop" is a patch of gravel.

But the job went fairly well. There are a couple of good write ups here, so I won't get into it except the areas that I had problems.

The whole job on the driver's side took about 3 hours. It's not rocket science, but some can be a little tough.

The first problem came in loosening the guide rod mount that threads into the strut. It was very tight, even after I loosened the lock clamp and spread the threads and squirted some oil in there. The problem is that since you have already taken the guide rod mount assy off, you have to hold the assy with one hand and try to loosen with the other, and then only a quarter turn at a time. Frustrating. Once I got the guide rod mount assy off, I was able to marvel at the beauty of German engineering - a well made piece. Getting the old mount out was easier by prying than pounding from the back. Don't forget to install the star-shaped rubber mount that comes with the kit under the backing plate.

The second problem came in getting the guide rod mount/frame assy back in. You have to turn the threaded rod into the guide rod while holding up the assy in one hand. And the threaded rod does not want to turn, it's very stiff. Lining it up to get it started was the hard part. I eventually used a bottle jack to hold it up while I turned the threads. Then the tedious screwing in the mount, a quarter turn at a time. My old mount was screwed in almost the whole way.

Once that's done, getting the aft-most frame mount in is easy, but the other one wouldn't line up. Using gentle pressure from the bottle jack against the forward mount and the steering linkage horizontally got it lined up, it was just a little more pressure than I could do by hand.

Once that was in, it was just a matter of adjusting the threads and bolting the cross member back.

The difference is amazing. When I used to drive down the dirt road to my house, the front end rattled the whole way. When I would come to a stop and then release the brake, the whole left suspension would give and clunk. Now, it's smooth as it should be.

I'm a happy camper. New seat, XM, and a rattle free suspension.

Thanks to all who posted on how to replace the guide rod, your help is appreciated!

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1984 300Sd 210k

Former cars:
1984 300D 445k (!!) (Strider) Original (and not rebuilt) engine and transmission. Currently running on V80 ( 80% vegetable oil, 20% petroleum products). Actually not, taking a WVO break.
1993 300d 2.5 275k. Current 120/day commuter
1981 300SD 188k (Hans) Killed by a deer

Good work, now go get the front end aligned.

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Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

This repair really does make for a nice, quiet, comfortable W126 ride.

If you ever start to feel a wobble on the right side, then its time to replace the tie rods and the idler arm bushing - easier to do than the guide rod mounts.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

Now the rear sway bar replacement will seem like a filter change

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BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
97 E420 Donor Car - NEED PARTS? PM ME!
97 S500
97 E300D
86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)

I hated doing those things, what a pita.

Good job though now that their done hopefully you will never have to replace them again.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

If this was such a well made piece why did it fail? Earlier MB suspensions would stay like new if you kept them lubed properly. At some point MB made a decision to put rubber in the suspension bushings rather than isolating the front subframe. Your witness to the results....

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Bill Reimels
Now down to one:
1972 300SE 3.5 W109 (Euro delivery)

I'm wondering about the alignment. I can't see how the guide rod affects it. All it does is locate the wheel assy fore and aft in relation to vertical. If it were too far one way, how does that affect alignment?

Glad to hear some of the other jobs are easier, though this really wasn't too bad.

I also replaced the kickdown cable on my son's '87 Volvo 240. That required lying on my back looking at an obscured view of a tiny cam inside the bowels of the automatic transmission and trying to get a small cable on its spring-loaded groove. And if anyone has tried to get the dipstick tube off of one of these cars (necesssary to get the pan off) I sympathise.

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1984 300Sd 210k

Former cars:
1984 300D 445k (!!) (Strider) Original (and not rebuilt) engine and transmission. Currently running on V80 ( 80% vegetable oil, 20% petroleum products). Actually not, taking a WVO break.
1993 300d 2.5 275k. Current 120/day commuter
1981 300SD 188k (Hans) Killed by a deer

Bill, I was marvelling at the aluminum subframe mount, not the guide rod.

The only compromise I can see that Mercedes made was in using engineering to get the ride and handling they wanted (I expect superior to past models) at the expense of having to replace parts occaisonally. I can tell you that this guide rod lasted for 24 years and 175K.

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1984 300Sd 210k

Former cars:
1984 300D 445k (!!) (Strider) Original (and not rebuilt) engine and transmission. Currently running on V80 ( 80% vegetable oil, 20% petroleum products). Actually not, taking a WVO break.
1993 300d 2.5 275k. Current 120/day commuter
1981 300SD 188k (Hans) Killed by a deer

My left guide rod makes a ton of clunking noises when its real dry out....its not in very good shape at all.....I don't think I'd be able to replace this myself, what tools are needed? I don't want to mess up anything if I were to try.....

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I'm wondering about the alignment. I can't see how the guide rod affects it. All it does is locate the wheel assy fore and aft in relation to vertical. If it were too far one way, how does that affect alignment?

The guide rod contols caster. Lengthen the rod more caster, shorten it, less caster. If you measured the distance between the mount and the LCA and put it back in exactly the same spot then you may be okay but it is better to get it aligned. Changing the guide rod length will also change the toe slightly on that side as the LCA moves back and forth in relationship to the drag link. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

pawoSD,
It doesn't take special tools. A socket wrench with metric sockets (seems like 17 mm, 14mm and 10mm was what I needed), an adjustable wrench, and the usual screwdrivers, a hammer, etc...

There's not much to mess up except the aligment, which sounds like it would have to be done afterwards anyway.

Here's how I look at it. It's probably a 2 hour job at a shop - 2x $75 = 150. They'll charge you $150 for the part for a total of $300. The cost for the part for you is $75. Your net savings is $225. Even if it took you all day (highly unlikely), you'd still make $225 for the day. Not a bad day's work.

Search the forum for guide rods and take some notes. It's not a difficult job, but takes some persistance.

If you need help, ask away - lots of us have done it.

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1984 300Sd 210k

Former cars:
1984 300D 445k (!!) (Strider) Original (and not rebuilt) engine and transmission. Currently running on V80 ( 80% vegetable oil, 20% petroleum products). Actually not, taking a WVO break.
1993 300d 2.5 275k. Current 120/day commuter
1981 300SD 188k (Hans) Killed by a deer

tenknots, did you have room to get at the guide rod mount kit off the lower control arm? the manual says you have to remove coil spring, looking at photo the bottom of coil spring looks like it sits slightly over the mount. How did you know the mount was bad? my SD needs the guide rod ball joint so I also wondering about the mount kit at the lower control arm and the guide rod subframe bushings.?

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1993 Mercedes Benz 300D 2.5 205K (ex wife's)
1984 Mercedes Benz 300SD 320K (SOLD)
2004 Mercedes Benz C240 75K
1995 GMC Sierra 2WD 5.7L 188K
1983 Mercedes Benz 300SD 239K (SOLD)
1987 BMW 325i 220K (SOLD FOR SALVAGE)

609 Certification

James, you do not have to remove the LCA mounting - the guide rod will pivot towards the engine enough to enable you to remove the mount. The bushing for the LCA side was in good shape and would be a bear to replace due to the spring. The problem is likely only the mount.

The symptoms were rattling front suspension going over rough roads and clunks going over speed bumps. The worse, to me, was after stopping and then releasing the brakes - the whole suspension "gave" a little and clunked. New guide rod mount solved the problem completely. The mount is a small ball joint, like you said, and it gets loose. There doesn't seem to be any danger of it coming out completely, but it does cause the entire wheel/suspension assy to move a little, which probably causes wear on other components.

The guide rod subframe bushings looked fine. The LCA bushing will require removing the spring to get off, but I'll bet yours is not bad. My car is 24 years old and it's still OK.

__________________
1984 300Sd 210k

Former cars:
1984 300D 445k (!!) (Strider) Original (and not rebuilt) engine and transmission. Currently running on V80 ( 80% vegetable oil, 20% petroleum products). Actually not, taking a WVO break.
1993 300d 2.5 275k. Current 120/day commuter
1981 300SD 188k (Hans) Killed by a deer