300SDL belly pan
 

The transmission belly pan on my SDL has some major tears. Is there a way to weld plastic? Are replacements expensive?

Lemme tell you, keeping if off is not an option. The SD is a lot quieter than the SDL with no belly pans.

Would it help if I lines the belly pans with a sound damping material like Dynamat?

Thanks,
Sixto
91 300SE
87 300SDL
83 300SD

Sixto,

I don't know of a way to repair it that will be effective. Mine are pretty busted up too, but still hanging on. A new one via online sources is about $150. Dynamat won't help, it's designed to dampend vibration, not absorb sound. You would want to add a thin layer of acoustic foam like what's on the engine shield, if anything.

Dynamat sells hood liner material as well.

Sixto
91 300SE
87 300SDL
83 300SD

Get some thin aluminum sheets like used in air conditioning systems, and pop rivet it to the belly pan where there is tears.

My belly pans went bye-bye a long time ago.. they are sitting in the back yard. Too much of a pain in the ass to take them down to change the oil and tranny fluid.

If you do it that infrequently then I guess you're ok. I change my tranny fluid 2 to 3 times per year (every 20k) and my oil every 3 weeks (3-4k miles).. i'd rather have a loud car than struggle with those damned pans.

You mite be able to use fiberglass mesh to repair the belly pan.

Too much of a pain in the ass to take them down to change the oil and tranny fluid.

Heh-heh! I hear that a lot. Once while doing a bunch of work on the car intermittently, I drove with both pans off for a few months. When I finally re-installed both, I noticed an immediate improvement in noise control, both outside the car at idle and inside the car on the freeway. As to the nuisance for oil & trans filter changes, I change my Delvac-1 at 10-15kmi and the tranny fluid at 25-30kmi, which means for me the pans need to come off about once per year. I can live with that "pain in the ass".... :D :D

Yeah, if you ever have a W124 up on a chassis lift, you'll see that the pans make the underside of the car really smooth. This helps with airflow management and may have some (probably slight) effect on fuel economy.

I am lost here-
 

My SDL doesn't appear to have the "belly pans". I am assuming they were removed, but were they standard on most of the later diesels?

Anyone have a short description of what they look like?

alec

The "belly pans" were standard on all 1986/87 SDL's, and 1987-1995 300D's. I believe they were used on the 1984-up 190D also but I'm not sure. The W124 gas cars (300E, etc) used a front pan only, under the engine, that did NOT have foam for noise control like the diesels. And they don't have the rera one for the tranny. But yes, someone swiped yours. They are extremely hard to locate used, and will cost ~$400 for both new from FastLane or Rusty...

As posted get some aluminum flashing at Home Depot. Use pop rivets with washers to attach them on the inside or outside of the pan. Then use epoxy glue to fill in the cracks. This should hold it for a while. Before applying the epoxy consider drilling small holes along the cracks for the epoxy to flow into and so it can "grap" the plastic material. Make sure you completely degrease the plastic or the Epoxy may not hold.

Dave

What I'd like to do is put some quick release captive fasteners on the belly pans to make them easier to remove and replace. The kind on aircraft service panels that take a quarter turn would be great. Maybe something as simple as the cotter pin arrangement used as hood pins.

Alec, does your SDL have thermostatcially controlled louvers on the lower forward edges of the engine bay? These only make sense if your car had belly pans at some point.

Sixto
91 300SE
87 300SDL
83 300SD

I will have to check
 

Sixto,

I noticed that there were louvers in the engine compartment somewhere (maybe on the sides of the lower verticle sound encapsulation panels - near the wheel wells), but I have never seen them open and never really paid much attention to them. I will have to check them out again.

If anyone else reads this post- does anyone think that I should be looking to add these panels if I happen to find some for a decent price?

I can't see that it is worth $400, but anyone let me know if they think that it is.

alec

The vertical, small side panels are foam lined for noise control. The one on the driver's side has a thermostatically-controlled element that will open the louvers at a certain temperature, but are normally closed. Unless you look at them on a HOT summer day you may never see them open.

And yes, if you can find a set of belly pans used, DEFINITELY pick them up! They are, IMO, worth every penny. Replace any of the metal clips that snap into the body if they are stripped (you'll feel the screws never tighten up), and buy new screws with the large, captive washers. The OE parts from FastLane or Rusty are ~$0.50 for the "nuts" and ~$1.00 for the screws. Get some spares, too - trust me. ;)

You're absolutely right. And if you want your newer, more refined SDL to sound noisy and obnoxious like an old SD, leave 'em off. :rolleyes: