I broke the alternator belt on my 85 300td, car got hot for a minute before i pulled over and realized what had happened.

It is a single pulley, i pulled a double pulley from pnp yard and plan to reinstall this one, however i have doubts abot how to do it, first of all i think i had the belt on wrong to begin with because the belt was going from water pump to alternator without looping in the crank, i just realized this and now wander how am i supposed to install the pulleys and belts on the new set up.

Any help appreciated.
Ep

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W123 1985 300TD naturally aspirated

How is it possible for the alternator to turn if the belt just comes from the water pump? How is it possible for the water pump to turn with that set up?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I have no idea, car came this way. and it did tun for 6k miles this way, charging system and cooling were not an issue.
I was at yard looking at the 300sd w126 which i pulled the new dual pulleys from and asked myself the same question, how did this thing run without going thru the crank.

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W123 1985 300TD naturally aspirated

There's certainly something out of the ordinary regarding his belt routing.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Be careful. The us spec 300s of that era run a double belt setup on the alternator. The non turbo euros of the same era run a single alternator belt setup like a 240d. The belts are different widths. If you use a us spec 300d belt on the single pully setup it will be too narrow and will slip, causing problems.


Don't ask how I know!

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Was there only one belt total apart from the power steering belt? Did that belt just go around the water pump pulley and the alternator, nothing else? Do you have any pictures? Something doesn't make sense.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

There were three belts, one to ac and one to ps and the one from water pump to alternator.

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W123 1985 300TD naturally aspirated

Did the AC belt go around the water pump?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Simply put if you got six thousand miles with some night driving the alternator must have been driven. Set up the way you suggest the alternator light would have not gone out after starting if the light was working. If you had a single pulley on the alternator and a double pulley on the waterpump or fan. The wrong alternator pulley was present. They did not have a belt that would be non adjustable between the crank and the water pump only as well did they?

Also For the single pulley to go bad it must have been driven. First measure the belt you removed. It should be between 39 and 40 inches. I no longer will be using the aftermarket car belts for the twin pulley set up. Instead using the 39 inch utility belts available at hardware stores. They install a little harder but not much and give you a fuller range of adjustment. Or that is my experience.

They just seem far better and do not initially seem to stretch in use. The normal car belts seem to be seriously lacking at a much greater cost. My last auto aftermarket belts were continental and junk in comparison.

Many thanks to ur post. I love it.

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