Joel,

Simple as that...

Joel,

I'm glad yours worked so easy. On my 300E it refused to come out, I even removed the tie rod ends from the arm and the bolt still hit the exhaust. I had the bushings removed as suggested but no go.

I cut off the bolt and put the new one in from the bottom.

Have a great day,

Glad you got yours done, not sure why they installed a relatively high maintenance items the way they did (engineers).

I hope to have mine back on the road by next weekend.

Enjoy your cars,
Joel

I think I understand and can answer the "why" question.

I expect that the European cars do not have the light off converters, the ones at the manifold. This means that the Euro cars probably have just pipe in that location. I expect that by reducing the exhaust diameter at that point provides clearance. This makes the light off converters that are required by the US Congress in their infinite wisdom the afterthought that causes this problem for you and I.

My $0.02,

I'm glad things went so well for Joel. I've got to think that the '92 might have a slightly different headpipe. Wouldn't take much difference to make that extra bit of needed clearance.

I had the same results as Larry.
Of course, I have exactly the same year and model.

First car- 1986 300E
1) Removed lower bushing in advance- no go
2) Pushed out upper bushing as well, still not go
3) Jacked up engine on mounts, various tilts- no go
Did not actually unbolt mounts- might work...
4) Detached headpipes and exhaust bracket at transmission, manipulated headpipes about - barely got old bolt out, but pretty mangled.
5) Did not think I could get new top bushing in with bolt without damaging bushing, so I gave up, and removed the rear manifold.

Second car- 1987 300E
1) Detached both headpipes, removed rear manifold, loosened exhaust mount at transmission, pushed headpipes aside, and voila!

This actually went very quickly, since I already had experience from dissassembling the first exhaust.

The 2 advantages here over the 'upside down' method from my perspective are:
1) If the nut falls off for any reason, gravity keeps the bolt in place. You could use a cotter pin or something to get over this fear, or rely on statistical improbability.
2) Torque values apply to the 'nut' in a nut & bolt situation. It is difficult to imagine getting any sort of torque wrench in there on the top with the exhaust in place. This seems like a situation where torque values really do matters, but this may be splitting hairs.

That said, the upside-down method is probably fine, since I tend to be overly anxious about such things.

I think Larry is right that the 'afterthought' pre-cats are the problem. Euro owners on this board probably wonder what the big deal is...

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1986 300E 5-Speed 240k mi.

My hat off to everyone who posted here on our idler arm fixes. I was wondering if I was going to do it the right way (move the pipes or cut the old bolt and new one upside down). I'm going to try the bushings out first the maybe scratch my head a bit. A BIG thanks to Steve, I think it was, for suggesting an upside down bolt and having no problems doing it that way, it does have a lock nut on it. What are the torque specs on the nut/bolt assembly for the idler arm?

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

Model 124 150nm
Model 201 110nm

Do the bushing out technique, it's straight forward and peace of mind from installing bolt properly.

Joel

WHEW, job is done, finally!! Bushing out didn't work as the pipe was too close, bolt only slid up about an inch. Spent most of the day using a small hacksaw to cut the bolthead off (if anyone else has to do theirs this way, turn the steering wheel all the way to the right) then another hour or so tapping out the remains of the lower bushing. The new ones went back in no problem, bolt upside down. I just hope that it's another 183,000 miles before I have to do this one again but know that it will be an easy one then.............now to prepare to tackle the heater blower motor, hope this one is a bit easier.

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

i've got a similar repair to do on my 87 190, i'm having some confusion as to where the idler arm is, and what it's purpose is... i think i have it confused with the control arm. my haynes manual isn't much help either.

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100 km/h is unsafe... it's fast enough
to kill you, but slow enough to make
you feel safe.

First poorstylishman, what does and where is the idler arm do. It is a pivot that connects the left side steering to the right, coming from the right wheel the tie rod goes to the idler arm, then at another point on the arm the drag link connects and crosses under the motor to the left side, the bushing is what usually goes bad causing wheel shimmy. I recently rebuilt mine and was both surprised and relieved that the bushing and bolt could be replaced rather than having to change out the entire arm (at more expense I'm sure). I am by no means an auto tech but have turned enough wrenches in my time and yes many times the various manuals don't quite cover what you are looking for. I hope that this helps answer your questions.

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

thanks bruce, i'm gonna have a look under the car tomorrow. i already have the bushing kit and i've experienced the shimmy... although it's only present between 55 and 60mph, and quite violent at that... almost as if there is a severe tire imbalance. But the tires are fine, as my steelies and snows were just balanced. i'm a little worried about the exhaust issue, though.

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100 km/h is unsafe... it's fast enough
to kill you, but slow enough to make
you feel safe.

Yup, between 55 and 60 was pretty bad on mine too. After the kit was installed it still smimmied some and it turns out that one of my new tires slung a weight off and made the situation worse. It's fine now, little or no shimmy but I do plan to replace the ball joints steering damper and all the tie rod ends and anything else that needs replacing. It should go another 184,000 miles with out much having to be done to the front end. Try that with an American car and you most likely will have had to replace all of the above twice (from my own experience).

BTW, the exhaust issue you stated, if it's the pipes in the way, look at the thread in this series/page, putting the bolt in upside down apparently makes no difference, got that from MB techs who have done it with no problems.

__________________
1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

yeah, i've read that thread, and it seems the most logical way to do it. would i need to do an alignment after the repair?

__________________
100 km/h is unsafe... it's fast enough
to kill you, but slow enough to make
you feel safe.

From what I've read on this site you should probably have the toe-in checked but I don't think this repair affects the rest of the front geometry. Mine was pulling to the right before and wearing the outside edge of the R/F tire, now it has a very slight (almost un-noticeable) pull to the right. I'm going to have my front-end realigned anyway after changing the other parts needed.

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

What an interesting thread!

I've done the idler arm bushing this summer (last summer) on my 300TE (euro) without reading anything about it before. The euro M103 also have the additional converters (pre-cats) behind the manifolds so the space for removing the bolt is very limited. I had to take off the exhaust.

Removing the exhaust is not as difficult as it sounds, four bolts to the manifolds and some rubber bushings in the rear - off it comes in one piece. I had the car on the lift so it was quite easy. For the bolts going into the manifolds you need a 13mm socket and a long extension or two. I sucked the nuts and the bolts with some anti rust oil (Rostloeser - don't know the english word now) and got them out without problems.

I don't think it's a good idea to mount the idler arm bolt upside down. In case you leave the nut for whatever reason, the bolt will slip out and steering is impossible. I know, there are many tricks in the workshops to save some time but not all are suitable for safety components like steering and brakes.

You don't need an alignment after this repair. As Bruce B wrote, the geometry will not change.

bis denn,
Christian

1989 300TE

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