Changing the Exhaust pipes in the w123 280CE

There was this annoying hole in the exhaust from last summer. It was the thin sheet under front muffler that had cracked and I had it welded just before the MOT last year. Unfortunately the job was poorly done by the workshop. Another lesson learned on why we should fix our own cars…. The fix ended up costing almost as much as the new pipes, so that was also dumb. On the very day before this summers epic 3000 km road trip of crossing Norway I had to change the entire exhaust system. The pressure was on to get it finished before the trip!

The poorly welded exhaust only got noticeable few weeks before the upcoming road trip, but another car was planned to be used so there was no pressure initially. Then because of circumstances it was decided to use the 280CE after all and the exhaust leak needed to be addressed asap. I decided to swap out all the pipes since some rust was starting to appear in the pipe welds and its easier to just swap the whole thing at once.

I ordered the exhaust less than two weeks before from Germany and it arrived two days before the road trip was starting. Just in time. It only costed me 500$ which I think is a bargain for a classic car! The quality also seems very good as well.

Welded front muffler w123
Poorly welded front muffler. Now junk.

Stage 1 – Getting the car up in the air

You need some good space to wrestle with the large exhaust system under the car. I drove the front of the car up on ramps then lifted the back of the car on jack stands so the whole body was up in the air. I leave the tires on for extra safety and don’t lover the jack either. Also make sure to block the front wheels from rolling on the ramps. I’m a fan of redundancy and here I even placed a couple of jack stands in the front which is kind of unnecessary, but makes it feel somehow safer.

Car on jack stands
Car up in the air. Potentially dangerous and safety should be on your mind. Here I have redundancy by leaving the jack in place and using redundant jack stands. Not recommended to be under the car during an earthquake…

Stage 2 – Removing the old pipes

This is usually the most time consuming job involving rusted fasteners and wrestling with stuck pipes. I was planning to only change the pipes up to the down pipes, since the down pipes are in a really good condition compared to the rest of the exhaust. The issue then become separating the down pipes from the pipes underneath the car.

exhaust clamps
Front exhaust clamps

I started removing the clamps for the front pipes and loosening the system from the transmission mount. Then unhooking the four rubber donuts from the rear muffler. To avoid too much stress on the pipes I placed something under the rear muffler for it to rest on, in this case a tree stub.

rear muffler 280ce
Rear muffler resting on a wood stub

Then the issue with sliding off the exhaust system from the down pipes. They were extremely stuck and you’re not able to twist them since it’s a pair of dual pipes. I was first trying to push them out with putting my entire weight with my legs and kicking. Then I tried heating the outer pipes with a heater torch. After a while struggling with no success and them not moving at all I had to make a drastic decision. I needed to cut them out without damaging the inner down pipes. This would mean the old exhuast would be trash, but it’s old and not worth much anyway.

cutting the exhaust pipes
Cutting the exhaust pipes.

In order to get the old outer pipe off, it needs to be split and then removed. It would be impossible to try pushing them off otherwise. I started by cutting the pipes across a few centimeters before the mating point. Here I used an angle grinder with a thin cutting disk for about half the way, then a manual cutting saw blade for the rest. A bit tedious, but will get the job done. The best would be to use a hack saw which is much safer than an angle grinder and faster than the manual saw. However I don’t have one. Maybe now it’s a time to acquire one?

exhaust pipes cut
Pipes are cut and also a slit is made lengthwise with an angle grinder. Care is taken to not cut all the way through to th einner time.

After the pipes were separated I could remove the old exhaust system. The old stubs of the outer pipes are just as stuck and a slit have to be cut down the middle and care have to taken in order to not damage the inner tubes. The only tool for this is an angle grinder. Watch out for sparks in your face!

Split the pipes
Split the pipes with a sharp punch and drive it in with a hammer. Eventually the metal will split. Use ear protection since it tends to be very loud.

When there is a slit along the length of the pipe I could use a punch with a sharp end and drive it into the slit until it grew larger and eventually the pipe will split along its entire length. Then it was super easy to remove the outer pipe.

Splitting pipes with a punch
Splitting the pipes with a punch. Super easy!

I was surprised of how effective it was, and it was sour that I wasted so much time trying to free the pipes with different methods before I ended up doing this. I was also surprised to find that there was essentially no rust that was binding up the pipes, instead it looked like the metal had expanded into each other and exhaust coke had made this kind of glue between them. Now that the old exhaust was removed, I could mount the new system on.

Stage 3 – Fitting the new pipes

This was the fastest part of the job. It was basically lining up the three exhaust part components, putting on the clamps and tighten them. When the full length is assembled I could slide it under and mount it to the down pipes. Don’t forget to slide on the clamps before joining the exhaust pipes.

Hangers different from old system
Shape of hangers different from the old system.

I found having some help with the assembly part is useful due to the quite heavy and large part that needs to be aligned, but also doable alone if you plan all the moves ahead in time.

The exhaust kit came with four new rubber donut muffler hangers. These rubber hangers crack at an incredibly fast rate due to the heat of the exhaust and they rarely lasts more than 1-2 years before they break.

New exhaust system
New muffler being very shining, almost looks fake.

Stage 4 – Road trip

Luckily I managed to sort it out the evening before and could leave the next day.The road trip went fine and went without issues all the 3000 km. The tail pipes of the new exhaust have a slightly different shape and the heat reaches the rear bumper a bit more making a subtle bluish tint on the chrome which is quite cool.

280CE in Lofoten

I have the habit of doing jobs in hurry lately where I needed to travel shortly afterwards. Unfortunately this introduces a lot of stress and takes the joy out of fixings cars a bit. I need to plan better indeed.

Cheers, Robs out.

Replacing the right side Mirror

There is nothing like a new mirror smell in the mornings

The right mirror has been fucked, it was broken while parked in the street and is just hanging on with some tape. It is actually not that obvious, however when traveling at highway speeds the mirror is vibrating by the wind. The angle of the mirror is not right when closely inspected either.

Used electrical right mirrors for coupes are quite hard to find actually, and new ones are very expensive at a Mercedes Benz dealer. So with this in mind I have tried to find a good used one. It is nearly impossible to find those kind of used coupe parts in Norway, too small market I guess, much easier too find used parts for sedans and wagons. Anyway I have been trawling the Internet for a used right side electrically operated mirrors for my coupe, all it took was some great patience and a will for not throwing in the towel and go directly to a Mercedes dealer.

Who would have thought that I found it on ebay in Germany while I studied in Thüringen? Only 130€, or anyway a lot cheaper than new of the shelf by an amount of 300€.

Old mirror hold togehter by tape
Old mirror hold in place by tape

plastic trim for mirror
Just flipping off the plastic trim to get to the mount

W123 mirror mount
Mirror is mounted by a couple of scres and the electric wire

Old and new mirror compared
Comparing the broken mirror, mechanism hold together with copper wire

Mirror 280CE
New mirror, good as new!

This was by far the easiest fix on this car so far, it took me only 5 minutes!

Rear Trailing Arm

Rusty trailing arm = death wish

How to get the 280CE approved for the road? Change the rear trailing arm since it is rusted. Not allowed to weld this critical part. So it is obviously number one priority. One can say that Christmas this year came early. I have been searching for a good used one as this for a long time and this particular one I got quite cheap compared to a new one! It even came with a good wheel bearing and the handbrake shoes with the cable. New trailing arms for the W123 from a Mercedes dealer can cost up to 3000$ and I was not up for using this amount of money when there are alternatives.

Rusted rear trailing arm
Rusted old rear trailing arm due to road salt

It weird that this one rusted and the other one is completely fine, also it rusted on a smooth curve and not on a edge.

New trailing arm for W123
New trailing arm

Like new this one! I painted it and changed the rubber bushings as well, however needed a workshop to put the new bushings on. I don’t have a hydraulic press in my basic workshop.

Welding the rear quarter wheel arch

Wheel arches mania

Started welding on the rear right wheel arch today, I hope to finish it tomorrow. It is hard to shape the metal to the smooth round shape of the wheel arch. Much easier if I had a replacement part, but these parts are rare and expensive since it’s a coupe and the rear section differs from the station wagon and sedan models. A part from an old wreck are hard to come by and would had the same rust problem in 99% of the cases. So better off doing it the hard way.

rusted right rear wheel arch
Rusted right rear wheel arch

Obviously I had to make a huge hole and remove the old crappy metal.

Welding metal into the wheel arch
Making some wheel arch

Cutting panels and shaping it is an art, and I’m not an artist, just a simple engineer.

Welding wheel arch
Welding first seam

Welding along the seam needs patience, the metal here is very thin.

Welding wheel arch
Welding continues

Also have to make the inner weld which I didn’t take pictures of.

Welding wheel arch
Adding lower part

This last part is a tricky one though. How will I be able to replicate the smooth shape?

Welding inner wheel arch
Welding the inner sides

Making the car water proof once again.

Wheel arch welded tight
Final polish before paint

Welding done! Think I have swung the hammer more times today than any other day in my life! An exact reshape of the arch was not possible from my side. Will need some filler to make up the last touches.

Wheel arch painted
Wheel arch painted but not done

Painting the metal and then applying filler.

Wheel arch finishing touches
Finishing the touches with some body filler to get the smooth shape, harder than I thought. Used a filler that is easy to sand.

I was quite pleased with the result, but is not as perfect as a replacement arch, will look into that in the future…maybe. So fast forward in time, here is the end result. Not bad for an amateur like myself!

Result after welding wheel arch
Wheel arch after painting

You can see the slight difference in color where the old and the new paint meet. I also think the shape of the arch is nice.