300SD speedometer sneding unit?

Where in the transmission is the speedometer sending unit for both a W116 and a W126 300SD? I have been under both cars but still can't find it. =(

Reply to
Mauricio Tavares
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In the 116 there is no sending unit. It uses an old style direct speedometer cable connection. Not sure if you know this, but if not, you may be looking for the wrong thing.

Reply to
trader4

What I mean is this: both the W116 and W126 get their info from the transmission. AFAIK, one (W116) is cable driven so have some kind of gear mechanism on the transmission the speedo cable goes to. And, the W126 has probably some Hall-based thingie which then sends a voltage pulse to the speedometer wiring. I am calling both the electronics and mechanics pickup sending unit because they both do the same -- measure shaft rotation -- in a different manner. I would guess they both are in the tail of the transmission so they are after all the gears and are not affected by them; the only gear that can cause them to be off is the differential (and the tire size).

So, if my terminology is not accurate, I do apologize; I do not claim I know that much about cars. But, I hope now we are talking the same language. =)

Now, why I am so curious about the different sending units? You see, I dropped a engine + tranny off a 83 300SD in my 75 300D. As you know, the W115 has mechanically driven speedo while the W126 has electrically driven. I am trying to decide if I am going to use the W126 speedo (just a matter of redoing the cluster) or use the stock W115 speedo and somehow change whatever I need to in the tranny to send a signal to the mechanical speedometer. To do that I need to know what I am looking for. =)

Reply to
Mauricio Tavares

Your 75 300D is a W115 body.....

That must be a tight squeeze for the primer pump.....

Reply to
Karl

Not horribly bad though I retired that pump in favour of a squeeze ball off a boat. Much faster and easier to get to. I did have to move the battery to the trunk since the power steering pump wanted to occupy the same location. Also the engine saddle had to be modified because the turbodiesel pump is deeper.

Reply to
Mauricio Tavares

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