Folks-

I just got around to replacing some belts in my '81 245 with K jet , it has a York AC comp that seems bolted to the body with no way of adjusting tension.
I did some digging and it seems that the belt was tensioned via 10mm nuts on the crankshaft pulley. Not sure how that works, but Ioosened all those 10mms and the tension hasn't decreased.
Am I missing something? I don't want to pull the whole pulley off and not be able to get a belt back on.

And of course I can't replace my Alt belts without removing the AC belt!

Any help SOON would be rad!

Abra

lucky you

The nightmare of early AC Belt adjustment.

the adjustment is made by adding or removing shims that fit between the front and the rear part of the AC pulley. The front half is bolted to the main solid pulley using short studs and those nuts

Take off the nuts and separate the front half, there will be 1 or more shims. Extras are stored on the front of the front half ---you will find them when you remove the nuts. If the studs come out with the nuts then you've got to separate the nut from the studs and re-insert the studs into the main crank pulle.

Then by adding or removing the shims between the halves the belt will ride higher or deeper in the slot. The higher up (less shims) the tighter the belt, the more shims the lower the loser.

Pain In the .....

you mentioned that you have a Haynes Manual

the one I have 240 Series 1974 thu 1984 covers this .... no pix tho

in the suplimental Section Chapter 13......52 and 53 AC compressor drivebelt - tensioning

53 Method for fitting the drivebelt

Ok so I got this figured out even before I read this! At least I think so.

What I did was cut the old belt off, the loosened the nuts and screws on the outter crank pulley, I never pulled it all the way off to see about shims etc. Then after installing the Alt belts I got the new belt installed, it fit pretty good/tight as is. I snugged up the nuts, turning the engine around 1/2 turn after a few turns of the nuts (I read about this somewhere). In the end the belt has about 1/4" of deflection, my only worry is since the I didn't have to crank the nuts down too much i'm afraid it might loosen up. i plan on checking the tension often until I'm sure its stable.

Funny thing is, I got the same size belt to go in that was in there previously, but the old belt needed the nuts on the pulley cranked down much more. I guess that makes sense though, the belt must stretch over time etc.

thanks for the advice! And yes, a major PITA.

I noticed that IPD used to sell a bypass kit for York compressors, basically it was a kit that allowed you to run a belt right from the PS pulley to the crankshaft, bypassing the AC. I see instructions for how to install it but it doesn't seem like they sell it anymore? I'd buy one if they made one!

Abra

"...my only worry is since the I didn't have to crank the nuts down too much i'm afraid it might loosen up."

Yes, it will. Tighten the nuts. The tension is not adjusted by torque on the nuts; it is adjusted by the number of shims between the sheaves.




--
Art Benstein near Baltimore

“The only true wisdom is in knowing you know nothing.” -Socrates