Question…. What water pump pulley size do you have on your 1984 or 1985 w123 300D with a plastic 9 blade fan?

The reason I am asking is I upgraded a friends ’82 300d with a small water pump pulley and plastic 9 blade fan that I got from an ’84 SD. I was under the impression smaller pulley is used with these fans because I’ve read the 9 blade fans can break using the bigger pulley. I have been using this setup with my car for a few years now, in which I also got it from a w126 300SD. But I remember when I went to get the belt for it (I told them is for an ’85 300D), they gave me the bigger pulley belt - 10 x 1037 and said it is correct for this year car. I ended up going back to get a 10 x 1000 belt.

Forward to this weekend…. Same exact thing happened at a different auto parts company. They gave me a 10 X 1037 and told me this is correct for this car. I believed them, tried to install it and the belt is too big. Crap!

Now before I sold my ’84, I don’t recall it ever having a small pulley even though it had a 9 blade plastic fan. I just never paid attention to it.

I am thinking that the ’84 and ‘85 617.952 (300D) came from the factory with a bigger pulley and the ’84 and ’85 617.951 (300SD) came with the smaller pulley. But only people with those years can tell me.

Thanks in advanced.

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1983 123.133 California
- GreaseCar Veg System

The pulley is separate from the pump, so the folks at the AP store may not be pulling your leg.
The belt should go by engine, vs fan blade composition.

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83 SD

84 CD

That is what I am figuring. So what I am trying to get at is do people with 617.952 motor with a 9 blade plastic fan, have the big pulley?

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1983 123.133 California
- GreaseCar Veg System

The SD came from the factory with the smaller pulley and the nine blade plastic fan. It should use the 1000 mm belts, but, it's impossible to install those belts without taking the fan and pulley off...........getting the belt in the sheave...........and then reinstalling the fan and pulley. The belts need to be about 1010mm to function properly.

Other members have had a similar issue with the SD..........but, not everyone.

So that's why the manual indicated the wrong size belt for my SD.

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83 SD

84 CD

Anyone out there who can confirm their '84 or '85 300D came with a big pulley on the water pump?

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1983 123.133 California
- GreaseCar Veg System

Looks pretty big on my CD 10 x 1035's.
The SD has 11 x 1015's, both have the plastic fan blades.

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83 SD

84 CD

Thanks for going out there to check, TM B! I thought that was the case for the '84.


Now somebody with an '85 300D, CD or TD can confirm if their car came from the factory with the bigger pulley.

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1983 123.133 California
- GreaseCar Veg System

My '85 300D-T (CA version) has a 7 inch pulley and a 9 blade plastic fan. In case someone wants to do a numerical list, the last 6 of my VIN is 211367 and the build date was October 1984.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Thanks Jeremy,

I forgotten to mention in the earlier posts that the smaller pulley is about 6 inches across and the bigger pulley is about 7 inches across.

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1983 123.133 California
- GreaseCar Veg System