fan belt issue - '79 e12 based 633

[bgriff]

Last week it was the engine and fan clutch, now I'm having an issue with getting fan belts off...and I'm stuck on the first one! I can't get the AC compressor to move enough to allow me to even come close to taking this belt off, sure, I could cut it off, but I'd never get the new belt on if I did that. Any tips from the pro's about how to loosen things enough to replace belts on a '79 e12 based 6er with a stock original engine?

[T.Hanson]

All three belts are fairly tight fits, and go on off by loosening, moving the alternator, power steering pump and a/c unit.

Crud, rust gets in the bolts and brackets to make getting the units to swing not so easy. Check you've got all the bolts / nuts loose.

[bgriff]

Thanks Tom, my problem is with the ac unit (the first belt to come off if I'm replacing all three), it only swings about 1/2 inch before it hits a 12mm bolt that holds the unit to the engine block, not enough movement to let me get the belt off. I'll keep working with it and take that bolt out if I need to, it seems to be the only thing keeping the ac unit from moving another 1/2 to 3/4". I can't be the only one who's had this problem, can I?
You're dead right when you say these belts are tight going off n on.

[Lenny D.]

Use a largish screwdriver, wedge the tip and a little more under the belt where it meets the pulley. Figure out which way you have to roll the car it 4th gear (you DO have a standard, yes?) and it'll pop right off. Reinstall is the reverse procedure. Works every time, and those belts, especially ther A/C belt MUST be tight or they'll slip.

[GripGreg]

I agree with what Lenny said. Or just cut it. Also, in my small shade tree opinion; if you pull the bolt, I understand, but, make sure you put it back BEFORE you install the new belts. Good Luck,,,,Greg

[Mike W.]

Use a 36MM socket on the crank nut and a decent sized screwdriver and it will roll right off. No biggie.

[bgriff]

Sometime, years back, I remember being told not to gouge or scar the V portion of the pulley - supposedly it would shorten the life of the belts, so when I'd change fan belts (I've only done it twice in my life that I remember), I used to take precautions not to damage the pulleys, now I'm thinkin that advice wasn't very factual, don't remember who told me not to use a screwdriver or prybar to get fan belts off, maybe some drunk in a bar. One thing I can say about this great group of do-it-yourselfers, you teach me something new just about every day....I appreciate it!

[John in Simi Valley]

bgriff,
As the others are indicating, the belt doesn't just lift off like the alt or P/S, it's rolled on and off. (?!?)
Think back when you were a kid when you installed a bicycle chain, get it started and rotate the pedal and let the chain "climb' onto the sprocket.
Same idea with the A/C belt.

Me, I'd take the spark plugs out before trying to turn the engine, it's just easier.
If your E24 has a manual transmission, chock the wheels, lift the rear and put it in TOP gear.
Turn the rear wheel to turn the engine. (This presumes you don't have a big wrench for the front nut).

As far a prying with a screwdriver, your previous advice is correct.
What Mike is saying, is true also; meaning you don't have to lift the belt out of the pulley, just get it started so it can "climb" out when you turn the pulley.

Have fun!

[bgriff]

John, gotcha my man, I've got it figured out now....just want to let my knuckles heal a little before I attack that ac unit again. Good analogy, by the way.

[Mike W.]

Sometime, years back, I remember being told not to gouge or scar the V portion of the pulley - supposedly it would shorten the life of the belts, so when I'd change fan belts (I've only done it twice in my life that I remember), I used to take precautions not to damage the pulleys, now I'm thinkin that advice wasn't very factual, don't remember who told me not to use a screwdriver or prybar to get fan belts off, maybe some drunk in a bar. One thing I can say about this great group of do-it-yourselfers, you teach me something new just about every day....I appreciate it!

It's one of those depends types of things. On my first BMW a Bav, it had been thru a minor flood and one or more pulleys were rusty. Before I cleaned them up I tried driving it and went thru the belts in a couple of days. I mean just flat out worn out. Cleaned up the pulleys with sandpaper and a wire brush and no more problems. So it all depends on how bad. Remember, that belt goes around a lot of times each day.