anybody have pics of the underside of their SD? - PeachParts Mercedes-Benz Forum

vstech · #1 04-10-2011, 11:41 PM

I have been working on mine for a while now (10+years...) and last week I was under there, and noticed a HUGE crack on each side of the trans tunnel from the front to the back of the car...
I wanna know if this is normal or not. I'm guessing not... I will get under a few of the other SD's I've got and take a look...
my car always has made a interesting noise over bumps and potholes... this might account for it.

leathermang · #2 04-11-2011, 12:03 AM

I have seen that happen somewhere... let me see..
OH yes...
When Wiley Coyote is chasing the Roadrunner... that happens a lot.. it splits down the middle longitudinally .....

vstech · #3 04-11-2011, 12:22 AM

I'm picturing a green vehicle driving down the road and a freeze frame underlined by latin phrases similar to Dieselious Pokius Squeakious (slow diesel squeaky) or something similar... thanks for that...

layback40 · #4 04-11-2011, 08:04 AM

Quote:

Originally Posted by leathermang

I have seen that happen somewhere... let me see..
OH yes...
When Wiley Coyote is chasing the Roadrunner... that happens a lot.. it splits down the middle longitudinally .....

& No John you may not fix it with the ACME "fix a crack" kit that the Coyote got on mail order.

Is this the same car that you had the suspension frame crack you posted on back a while ago?

If it is you have one seriously fatigue problem in the car!!
Makes me wonder WTF the car has been used for.

My old 300D did 800k miles of which about 400k miles would have been on what are best described as goat tracks & yet it has no cracks.
Has the car had some sort of vibration all its life & so has shaken the s##t out of it?

Its as though its reached it fatigue life. I thought for a MB that was around 2 1/2 million miles with normal driving.
Your thoughts .......

vstech · #5 04-11-2011, 08:09 AM

I know the car has an excess of 475K on the clock. a LARGE woman drove it prior to my acquisition. Yes, it's the same car with the crack in the subframe up front. it is also the same car that will do 0-60 in under 10 seconds. I'm now afraid to put the car on a lift to get a good picture of the cracks... don't want it splitting apart! I'll keep inspecting it along with the other cars, and I may transplant it's goodies into another car, or pull and mothball them for later, or even sell them.

layback40 · #6 04-11-2011, 08:18 AM

Quote:

Originally Posted by vstech

I know the car has an excess of 475K on the clock. a LARGE woman drove it prior to my acquisition. Yes, it's the same car with the crack in the subframe up front. it is also the same car that will do 0-60 in under 10 seconds. I'm now afraid to put the car on a lift to get a good picture of the cracks... don't want it splitting apart! I'll keep inspecting it along with the other cars, and I may transplant it's goodies into another car, or pull and mothball them for later, or even sell them.

A lift would be the safest thing to have the car on to get under it.
The lift points dont cause the torsion loads that the suspension does.

If the crack is related to the seat mounts, all should be ok.
Best wait till we all get a look at your pics.
Has the car been submerged in sea water at a young age? You may have stress corrosion cracking.
Is it from the rust belt?
I find the details you give some what intriguing.

vstech · #7 04-11-2011, 09:13 AM

no, no rust... it's like it's been dropped at some point in it's life... odd. it does sag in the rear when I have 1000# in the back... but I figured that was normal. I have to go to the transmission shop with it sometime soon, so I'll get pics of it when I do...

layback40 · #8 04-11-2011, 08:54 PM

Quote:

Originally Posted by vstech

no, no rust... it's like it's been dropped at some point in it's life... odd. it does sag in the rear when I have 1000# in the back... but I figured that was normal. I have to go to the transmission shop with it sometime soon, so I'll get pics of it when I do...

Everything would be bent up if it was dropped. More likely it has been used regularly on a badly corrugated road.

With my machinery, first sign of cracking, it gets fixed (welded) & then sold.

300D85 · #9 04-11-2011, 10:24 PM

Rust Examination - 82' 300SD

vstech · #10 04-11-2011, 10:50 PM

wow, I forgot about that thread... no pics of the area I am concerned about in my car... lots of great pics though.
my car has NO rust in anyplace of consequence... pristine compared to those shots...

t walgamuth · #11 04-11-2011, 11:34 PM

Are you sure it is in the metal and not just the undercoating?

vstech · #12 04-11-2011, 11:43 PM

not sure of anything yet. I have to get the car back from my sister, and get it up on a lift.
it was a pretty good sized crack, and I felt it with my fingernail... it could have been just the undercoating though. if it's just the undercoating, I'll clean it up and recoat it.
either way, pics will follow in a few weeks when I get it back.

layback40 · #13 04-12-2011, 09:35 AM

Quote:

Originally Posted by vstech

not sure of anything yet. I have to get the car back from my sister, and get it up on a lift.
it was a pretty good sized crack, and I felt it with my fingernail... it could have been just the undercoating though. if it's just the undercoating, I'll clean it up and recoat it.
either way, pics will follow in a few weeks when I get it back.

"a LARGE woman drove it prior to my acquisition"

John,
Best there is no doubt that you were definitely not referring to your sister !!!

I hope it is just the undercoating. Will need cleaning off & replacing to stop rust starting.

vstech · #14 04-12-2011, 09:46 AM

Quote:

Originally Posted by layback40

"a LARGE woman drove it prior to my acquisition"

John,
Best there is no doubt that you were definitely not referring to your sister !!!

I hope it is just the undercoating. Will need cleaning off & replacing to stop rust starting.

nah, my sister is 5'9" tall, but she's in the 140lb range... the woman who gave up on this car and left if for me was in excess of 400lbs...

tbomachines · #15 04-12-2011, 10:08 AM

Quote:

Originally Posted by vstech

nah, my sister is 5'9" tall, but she's in the 140lb range... the woman who gave up on this car and left if for me was in excess of 400lbs...

The seat must look like a pancake! They wear bad enough under normal loads...