240 DL 1989 Alternator replacement

Cassman500 · Post by **Cassman500** » 29 Nov 2009, 00:51

Im about to replace my alternator which has recently died in my 240, i was wondering if anyone had any tips for this. i noticed im going to have to remove a radiator hose. is there any easy way to drain the radiator before i remove it? also is there a serpentine belt tension pulley i can loosen to remove the old one? Appreciate the help, Andrew

Post by **billofdurham** » 29 Nov 2009, 04:19

You shouldn't need to remove a radiator hose to replace the alternator but if you feel it is necessary the coolant can be drained by removing the bottom hose from the radiator and draining the coolant into a container. You don't need to drain it all, just enough to drop the level below the top hose. Before draining any coolant set the heater controls to max heat to prevent an airlock in the heater and leave them at max heat until you refill the system which should be done slowly.

There is no tensioner per se on the 240. The tensioning is done by moving the alternator. At the top of the alternator there is a tensioning arm with an elongated hole in it. There is a square necked screw which goes through the arm and fastens to the alternator. At the end of the arm there is an adjusting screw. As you are removing the alternator forget about the adjusting screw. Slacken the nut on the square necked screw and push the alternator to the side, releasing the tension. If the alternator won't move, loosen the flange screw underneath the alternator until it will. With the belt off remove the wires from the back of the alternator, making sure you know which goes where. Remove the two bolts you have loosened and remove the alternator.

Installation is, as usual, a reverse of the above. At this time don't fully tighten the two bolts. Leave them slack enough to allow the alternator to be moved with a little pressure. Put the belt around the pulleys and pull the alternator to take up the slack. Holding the alternator so the belt is reasonably tight adjust the tension using the adjusting screw on the end of the tensioning arm. The belt is tensioned correctly if you can depress it 5/16" with normal pressure from your thumb midway between the fan and the alternator.

The attachment shows all of the alternator parts to which I have referred.

240 alternator.pdf: (884.23 KiB) Downloaded 3405 times

Bill.

Cassman500 · Post by **Cassman500** » 08 Dec 2009, 13:07

Thanks for the help. I'm currently in the middle of replacing it. i got the the top nut off and the square headed bolt. i got the bottom screw off also but i can not for the life of me get the bolt that slides through the bushings and the alternator out. I've soaked it in liquid wrench. banged on it the best i could (real tight quarters) but it will not slide out. I slipped the belts off and have been trying to wiggle it around to help loosen the rust or whatever is holding it in there. I feel like my next option is to take a torch and heat up the outside to expand it and hopefully slide it out. Is there something I'm missing here? or a better way to approach this. Thanks a lot Bill you've been a huge help the last few months with the problems that have been popping up!

Post by **billofdurham** » 08 Dec 2009, 15:15

I'm not sure which bolt you are having trouble with. Can you give me its number from the diagram?

Bill.

Cassman500 · Post by **Cassman500** » 08 Dec 2009, 17:30

7, the one that slides through the bushings and the alternator. i got the nut off of the end, but i cant slide it out.

Cassman500 · Post by **Cassman500** » 08 Dec 2009, 17:31

i didn't even have to put a wrench on that end to get the nut off, the back. thats how stuck it is. its been drenching in liquid wrench all night. hopefully that'll do something

Cassman500 · Post by **Cassman500** » 08 Dec 2009, 21:35

Okay i realized that the last post made no sense. The hex head part of the bolt (7), did not need a wrench on it to keep it from rotating while i removed the nut at the other end. i was able to yank on it with all my might and break it free. Therefore the carriage bolt (7) has to be lodged in the bushings and alternator pretty well. Like I said I've been soaking it in liquid wrench and banging on it to break free the rust. Tomorrow I'll see if any of that has helped. I feel like this is an isolated problem with my vehicle, I'm just looking for a different technique to get the bolt out. I'm scared if i use a torch and try to heat the outside to expand it to loosen it up that i will melt the rubber bushings. Any ideas would help a lot, Thanks, Andrew

Post by **billofdurham** » 09 Dec 2009, 11:50

It did make sense but I am fluent in 'strange' language.

Is it possible to pivot the alternator far enough towards the passenger side of the car to get at the flange screws, #10, and remove the bracket with the alternator attached?

Not having a similar car to look at I am having to work from diagrams and photographs.

Bill.

Cassman500 · Post by **Cassman500** » 06 Feb 2010, 23:46

I know this is fairly late but i ended up having to take the mounting bracket off in order to remove the bolt from the alternator and the bushings. There was some serious built up oxidation on the bolt! which was preventing it from sliding out. A good bath in liquid wrench did the trick.

Post by **billofdurham** » 07 Feb 2010, 12:05

Good to know it has been solved. Thank you for the update.

Bill.