That !*~^%* air filter bracket - 1983 300SD

[Thomaspin]

Well, wouldn't you know it, the wretched air filter bracket on my 300SD fractured again. The first one lasted 10k miles. The second lasted 130k - only because after it broke soon after installation, I had a Ruddy, Great Big Weld placed on it. When it broke it did so in 2 places, looking beyond redemption. The third broke in 2 places and one of the pieces was lost. That lasted 10k miles.

Now the fourth has gone - broken in one place. The fractures occur either at the trailing or leading mounting location, closest to the engine. This is a 1983 300SD with the big air cleaner mounted near the engine on the passenger's side. Car is about to roll over 200k miles.

So I'm having not one but four RGBWs put on it by the local welder - two atop, where they fracture, and two around the periphery to see if I can get some life out of this thing. I just hate that loud rattle when I start it first thing in the morning....

Am I the only one with this failure rate? The engine is well tuned, motor mounts are fresh, air filter rubbers are fresh, little shaking at any speed.

[dmorrison]

Thomas
Did Mercedes redesign the mount on the latter year SD's?
If so maybe they got it right and they don't break.

Or maybe it would be cheaper to buy a welder *G*

Dave

I just had another air canister bracket break. I studied why it might have failed and I believe I may have found the problem.
When I put the air canister in place I noticed the nozzle that slides into the oil drain would hang up, so that the nozzle was not down into that tube. Not only did it drip oil all over, but it broke the t shaped bracket.
The solution is to get your hand under the air canister everytime you remove and replace it. You should be able to feel that nozzle and then make sure it is not sitting on top of the drain tube. Then it is safe to tighten the nuts holding it in place.

[R Leo]

Thomas,
I agree, the daggone air filter bracket has to be the most frustrating, under-engineered, POC on the entire car.

My TD ate it's first set of rubber mounts in a little less than 5000 miles and SWMBOs 300D broke (and lost) the back part of it's mount in a shade over 2000. These aren't abused, shaking monsters either.

There has to be a better way of doing this job that does not involve a misapplication of a K&N racing filter, hanging out there, exposed to the elements.

I'm contemplating a separate air box of some sort, mounted to the fender with flexible tubing running to the turbo intake.

[Thomaspin]

I have always been very careful to insert the tube correctly, using my hand under the air filter canister, so that's not it.

No oil leakage, though that would not necessarily be a symptom, as I have minimum blowby....

Dave - I think on the 1985s (at least the few CA models I have seen) they moved the air filter closer to the right front passenger side, and the whole thing got a lot smaller. It may be fender mounted, so lower vibes, than the engine mounted variant I have. I am blessed (?) with the whopper on the earlier cars.

Thomas,
First, please allow me to thank you for your various diy accounts on your website that is now listed as a sticky at the top of this forum section. I personally listed your site in my favorites section some time ago! Thanx.

Anyway, something that you may want to try.....................posted the other day, sorry to say that I don't recall who did the posting.........REPLACE your engine shock absorbers.
Best wishes always, and keep those diesels humming!
Spo out.

Why not bring the bracket and some strips of thick stteel to a local welder and have him/her stick them all over the bracket? Or insted of metal sheet you could use some reasonaby thick steel rod from the local hardware store?

Me, I just replaced mine with a PVC tube directly attached to the turbo, a K&N, and a homemade oil seperator. I love this mod. It makes the engine bay soooooo much less cluttered, I can hear the turbo real nice, and I don't need to buy any more of those FU**ING rubber stumps or the thinmetal bracket!

[JerryBro]

They have failed on both of mine. It's just a crappy design. Take a metal diving board that doesn't flex well and hang a lot of mass at it's end, then shake alot in the the wrong direction. There are a couple of things that can be done to improve it.
1. Lower the mass, not likely.
2. Beef up the diving board. Just a band-aid.
3. Add another support brace under the assembly.
4. Scrap it and start over.

I've been looking at the air cleaner in the Lincoln and wondering if it can be modified for the Benz. The only complication is the oil separator. While the 240 assembly would work, I want a little more elegant solution.

Jerry

[jbaj007]

Some folks take an extra rubber bracket bumper and drill the air cleaner cover on the side to attach it with a recessed bolt; to act as a vibration dampener/limiter between the air cleaner cover and the valve cover.

[rwthomas1]

I too have fought with the stupid air cleaner design. I just replaced my engine shocks but the air cleaner still vibrates quite a bit. Remember the shocks keep the vibration from reaching the chassis but it is still happening! There are two solutions I see:
1. Replace entire assembly with a home-brew setup. K&N w/240 separator, etc.
2. Reinforce the metal bracket. I am planning on seeing if more supports could be added and additional rubber isolators used. If you could add three more mounting points with the same style isolators used then I think the aircleaner may be well enough attached to not bounce around so much. Just a thought. RT

[Thomaspin]

Cost all of $10.

[Thomaspin]

I had the welder add a bead around the curve to stave off the inevitable.

New bracket by mail order? Over $60.

I use the heat shields (p/n 617 094 02 20) with the rubber mounts and find that these greatly extend the life of the rubber.

Though only one side fractured, I had both welded as past brackets have broken at both the leading and trailing ends.

[Wes Bender]

Thomaspin -

First, let me also add my thanks for all of your good work on your site.

In looking at your pics on this post, I will bet that your next bracket failure will happen fairly soon. (Hope I'm wrong though.)
The heat from the welding probably made the metal in the vicinity of the welds somewhat brittle and that may lead to failure again.

I've don't seem to be having trouble with the brackets on my two '82 300Ds.... but I'm not sure why. They shake more than I would like, but not excessively.

Cheers,
Wes

[Thomaspin]

Thanks, Wes. Actually, the last time I had one welded it ran 100k miles before breaking at the weld....let's hope I am as lucky this time.

[haasman]

I was told these brackets only fail because of idle time, not running.

I wanted to ask if you have a rough idle? Does your injection pump rack dampener need to be adjusted or replaced?

Thanks for your work on your site. Very helpful.

Haasman