What part swaps upgrade the 300D?
 

Hello,

I would like this thread to start to compile parts swaps for the W123 300D from other Mercedes chassis and models. I am not going for step by step tutorials, more interchangeable upgrades and associated parts needed. Think of it as stuff to look out for at the junk yard. When the thread is exhausted, a handy summary of easy W123 300D upgrades could be made.

I did not find this information easily compiled. I saw bits here and there. Stuff about possible front and maybe rear brake swaps, sway bars from W126’s, and some stuff like that. It would be great if everyone could put their heads together on this.

Seems like there was a thread a while back on this same subject where things were compiled.


The Steering knuckles (Spindles) assy from a W116 and W126 will swap over.

The Trailing Arms from a W116 and W126 up to 85 will swap over.

The Differential from a W116 and W126 up to 85 will swap over.

The seat bottoms (Spring Box) from a W126 all the way to 91 (end of production) will swap over. Maybe the W116 will too.

The rear Rotors and Pads from "I think" back in the 60`s thru 91 are the same. W109, W109, W115, W116, W123, W116. I forget the chassis # of the Fintails (Heckfloose) W111?

The front Vented Rotors from a W126 will swap over. First generation, 81 - 85 you can still use the 14" wheels. Second generation 86 - 91 you must go to a 15" wheel or larger, change the backing place and caliper.

The clutch (Disk, FW, PP) from a W115 220D, W123 240D, 300D NA, are the same. Some of the Euro W126 (280SE) had a 4-spd and the clutch may be the same too.

The 4-spd gear box in a W115 220D, will bolt into a W123 as well. a 4-spd or 5-spd gear box and peddle assy has been grafted into a W126.
Look up Sirnick84 thread on it.


Charlie

Does the brake swap only require the rotoros, pads, and callipers? Are they just vented or also a larger diameter? It has been a while since I needed to changed my brakes but I figured I would also need some sort of bracket from the W126.

You mentioned trailing arms and knuckles are these upgrades of some sort or basically just the same parts on another car?

Does anyone know about sway bars?

There are probably heavy-duty suspension items of all kinds that were/are available from the factory for the W123, including sway bars. That's not adapting parts from other models but the result is what you want.

The W1213 instrument cluster has a rectangular aperture blanked off (was used for column shift cars) that can be used for an outside temperature display as found on W124 and other models. I don't think this is a simple bolt-on, it probably would require more work. I think someone posted about this in the past few years.

Jeremy

Yes. You dont need any brackets. The rotors have the same diameter.

Using the second Gen W126 Rotors, you will need the backing plates, Rotor, and Caliper. and 15" or larger wheel. also these Rotors are larger diam and thicker than the first Gen W126.

First Gen W126 you will need the Rotor and Caliper and maybe the Backing plate these are vented (as well as the second Gen W126) and you can still use the 14" wheel.

The out side Temp display from the W124 fits right in the center blaked off space (where the batt, oil, gp lights strip) you will need to remove the wiring cable, sensor from a donor car.

http://www.peachparts.com/shopforum/diesel-discussion/251755-w126-outside-temperature-display-installation-w123-300d.html

The front Sway Bar used in the 300TD is an up grade for the 240/300D/CD. the difference is 21mm vs 24mm. you will need to order the TD Bushings.
123-323-12-85 or W0133-1807027.

The rear Sway Bar is 13mm as I remember, there was a 15mm available (NLA) from what I know. Difficult to find even in the Yards.

Charlie

Are the calipers the same or different? Are the calipers two piston on the older SDs? Newer ones?

I will have 15's (bundts) on my CD once I mount tires.

I ordered the #3 of the last 15mm bars on my car that I no longer have (and am missing for a winter beater).

The brake upgrade is totally worth it, as is the 300TD bar. Everything else is kind of meh.

What are you looking to do?

https://lh4.googleusercontent.com/-Y...a_wma_0604.JPG

I miss her.

When upgrading the calipers I'd put in new hoses as a precaution. the old ones will have taken a shape and if the new caliper requires a different shape the hoses won't last long if reconfigured.

The exterior door mirrors of early W116 (1977) seem the same as W123.

Steel braided ++

Steering wheels, they pretty much all fit from W140 backwards, with some work.

Do you have a source for braided steel lines for W123s? Pelican doesn't list them.

I'd bet dollars to donuts the 124's are the same length. I think my old ones are still laying around if you can get the lengths on the W123's.

12" rear, 14 3/4" front. Same for 123, 124, and 126. Pelican lists the same 129 part number for the fronts for all three, and the same 126 part number for the rear on all three.

Are you saying you have a set of braided stainless brake lines just laying around?

If you go with the PRE 1986 SD (vented) front rotor, you'll need a different caliper, the thickness is different.

First pic is a 123 front rotor, the second is a 126 front rotor. The calipers have different part numbers.

The diameter may be the same and it doesn't matter about 14 or 15 inch wheels.