300SD vs. 300D A-Arm - PeachParts Mercedes-Benz Forum

nickofoxford · #1 01-30-2009, 08:59 AM

Hey guys, me and a friend are looking at getting a beat up 300SD locally and using it for parts. His 82 300D needs a new A-Arm because it is rusting where the shock goes through. The SD in question is an 79 300SD. This is pretty much the deciding factor in buying the car. I feel bad for the poor SD, I may just part it out because of the serious rust but it might just need a lot of love.

mobetta · #2 01-30-2009, 09:41 AM

what is an A arm? do you mean rear trailing arm?

rrgrassi · #3 01-30-2009, 10:04 AM

My old Pontiacs and Chevies has upper and lower control arms that some referred to as upper or lower "A" frames.

Suspension parts like that really need to be gotten from a w123, as w116 and w126 cars are a different animal. I do not think those parts are interchangable.

aaa · #4 01-30-2009, 10:55 AM

I have a W126 arm in my 300d.

nickofoxford · #5 01-30-2009, 11:20 AM

Quote:

Originally Posted by mobetta

what is an A arm? do you mean rear trailing arm?

Yup that's the one, sorry about my terminology. The one on the 300D now is rusted almost half way around where the shock hooks into it.

rrgrassi · #6 01-30-2009, 11:20 AM

Quote:

Originally Posted by aaa

I have a W126 arm in my 300d.

Where?

nickofoxford · #7 01-30-2009, 11:20 AM

Quote:

Originally Posted by aaa

I have a W126 arm in my 300d.

Interesting, did everything bolt up normally.. It would really be nice to pick up the SD and get some parts off it.

rrgrassi · #8 01-30-2009, 11:23 AM

Quote:

Originally Posted by nickofoxford

Interesting, did everything bolt up normally.. It would really be nice to pick up the SD and get some parts off it.

The '79 SD is a w116. If aaa has a rear trailing arm from a w126, then that is cool. I do not know if the w116/w126 rear traling arms are the same. Part numbers would be good to have, and see if they are, in fact, the same part number.

aaa · #9 01-30-2009, 11:37 AM

It has W126 in the part number, so I do not think the part number is the same. This is the right rear trailing arm btw. I am not sure how easily it goes in as I didn't install it.

nickofoxford · #10 01-30-2009, 11:41 AM

Quote:

Originally Posted by aaa

It has W126 in the part number, so I do not think the part number is the same. This is the right rear trailing arm btw. I am not sure how easily it goes in as I didn't install it.

That is the same exact one we need to replace as well. I think im going to stop by the local NAPA and look through the books to compare part numbers maybe it is the same?

mobetta · #11 01-30-2009, 03:15 PM

fastlane list the 123, 126, and 116 T arm as part 126 350 (16R-15L) 46 only $1242.50!!- but that includes the HUB!!

so it seems that it would be the same. a quick look at the EPC net would verify this. subscription is free, but it does not run on a MAC.

I got a used pair from TN shipped to me for like $240 a few years back. it is a job. 2 days, mostly spent trying to get the subframe mounts loose.

nickofoxford · #12 01-30-2009, 09:50 PM

Quote:

Originally Posted by mobetta

fastlane list the 123, 126, and 116 T arm as part 126 350 (16R-15L) 46 only $1242.50!!- but that includes the HUB!!

so it seems that it would be the same. a quick look at the EPC net would verify this. subscription is free, but it does not run on a MAC.

I got a used pair from TN shipped to me for like $240 a few years back. it is a job. 2 days, mostly spent trying to get the subframe mounts loose.

Sounds good, NAPA confirmed that the numbers are the same! Looks like we're gonna jump on this SD and see what kind of luck we have..

This should be a real blast

Im going to stock up on PB Blaster, any tips and tricks??

pawoSD · #13 01-30-2009, 10:13 PM

That seems hard to believe, in having worked under both a W123 and W126 extensively, they LOOK different, perhaps they fit and will perform the same task in either chassis, but they aren't the same by appearance, the W123 one looks a little narrower and taller, and the W126 one is wider and flatter looking. Maybe I'm crazy.

charmalu · #14 01-31-2009, 11:07 AM

Here is a cross reference chart showing what fits what.

www.peachparts.com/shopforum/showthread.php?t=229825

hope this helps.

Charlie

nickofoxford · #15 01-31-2009, 11:51 AM

Quote:

Originally Posted by pawoSD

That seems hard to believe, in having worked under both a W123 and W126 extensively, they LOOK different, perhaps they fit and will perform the same task in either chassis, but they aren't the same by appearance, the W123 one looks a little narrower and taller, and the W126 one is wider and flatter looking. Maybe I'm crazy.

Huh.. Im thinking if they are different in appearance but do still bolt up I'll just go ahead and put two 126 arms on my buddies 300D..

Charlie, you da' man. Thanks for sending me that I looked all over the place on here yesterday for something like that. Looks like nothing but good news so far so I think we'll go ahead and try it out.

Just curious guys, whats the demand for parts from a '77 300SD on here?

If the motor is good, i'll be using that in my 240D, and then making a biodiesel generator for the family business (mushroom plant) out of the 240D motor