300E exhaust removal
 

I'm going to drop the exhaust to replace the idler arm bushing, rather than cut the bolt.

I'm just not sure what exhaust seal rings I'll need and which exhaust nuts to get. I ordered a handful of each 14X10, 8X12 nuts and both types of seal rings just to have everything on hand and since they were cheap.

Put some anti-seize compound on any threads (including O2 sensor) for re-assembly?

What other unknown is there that would greatly cause me to reconsider removing the exhaust?

Thanks for any help, it is greatly appreciated as I am a novice.

You won't need any parts unless the rubber hangers are broken.

You don't need to remove the O2 sensor. Simply raise the passenger side front carpet, disconnect the connectors and push them through the hole in the driveshaft tunnel.

Remove the four nuts at the manifold, the hanger at the transmission paying close attention to the orientation of the rubber bushings, and then unhook the rubber hangers at the rear. For your purposes, you probably won't need to unhook the rear hangers since you're just trying to get it out of the way for the idler arm bolt.

Upon reassembly, put antisieze on the manifold bolts if you want.

That said, I've been there and done that. It is much simpler to just cut the bolt. In order to get all the slack out of your new idler arm bushings you will have to tighten the SNOT out of the idler arm bolt. For that reason, there is absolutely no danger, when putting the new bolt up from the bottom, of it coming loose. That is Steve Brothertons method, and if it is good enough for him it is certainly good enough for me. I put my idler arm together that way a few years ago and it is still tight. I check it, along with many other things under the car, at every oil change.

Good luck,

Thanks very much for the reply Larry, I thought my post had slipped through the cracks.

What kind of torque are you talking about on the bushing, air gun levels? Or is it obvious when tightening it that the bushing hasn't seated all the way until sufficient tightening is achieved?

Replacing Idler Arm Bushing
 

I was able to replace the idler arm bushing on my '88 260 without removing the exhaust and was still able to get the new bolt in the right way. Once the bottom nut was off I pried out the lower plastic bushing and loosened the upper bushing allowing the bolt to skew past the exhaust. "Installation is the reverse of removal" as the Haynes Manual would say.

I'm not sure if the exhaust on the 300e is different from the 260 in which case my method may not work.

Mine has the catalytic conv. which gets in the way.

I'll definitely try it your way first, I think Larry Bible said it could be angled out but maybe thats only without cats.

thanks

Sometimes you can manage to get the bolt out the top. I think that the variable is the condition of the motor mount. If the motor mount on that side is sagged, then it's just enough to limit the access.

I say that, but I think I even tried raising the engine before and still didn't have enough clearance. Of course you should try first to get the bolt out the top, if for no other reason to keep from having to cut it.

As far as how tight for the idler arm bolt? Tighten until there is no slack. You will have to push hard on the idler arm to feel the slack. It may very well take a 1/2" impact wrench to get it tight enough.

Good luck,

I changed the idler arm bushing and rear flex disc wednesday night. I ended up removing the exhaust system since the driveshaft nut was obscured. The idler arm was sooo easy. Tightened it to 150Nm. That information I got from another board while this one was in surgery.

The flex disc was harder. The grease seal that is on the end of the driveshaft was cut up a little and the copper ring inside it had a chunk missing. I put some grease in it and put it back together. So far, the driveshaft hasn't separated from the car at 80mph, pole-faulting it over the center divider into oncoming traffic, knock on wood.

Thanks for the help.