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1989 740Ti A/C belt to alternator or crankshaft?

89_740Turbo

New member
Joined
Apr 10, 2018
Location
Central New Jersey
I haven't really sat down to take a look but does my 1989 740Ti A/C compressor have a belt that goes to the alternator or the crankshaft? Pretty sure it's the crankshaft but I haven't had time to look.

I need to buy a new A/C belt for the car. Thanks
 
There is the tension adjuster on the front of the compressor. The rear of the compressor has a locknut on the bracket to hold the adjustment at the rear. You have to loosen both to get a good adjustment.
 
Be careful! Ive had 2 bolts break on me tightening the alternator, and thr other while driving. Get a good replacement if it does.
 
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Be careful! Ive had 2 bolts break on me tightening the alternator, and thr other while driving. Get a good replacement if it does.

Youre doing it wrong then.

the thin, long M6 bolt(10mm head) should only be loaded when adjusting belt tension while two front and back M8 bolt/nuts (12/13m heads), are loose.

when the belt tension is correct, tighten the two M8 bolts, locking it in place, and relieve tension on the long M6 bolt. It isn't tight or under load otherwise. Keep it lubed, and it won't break.
 
Youre doing it wrong then.

the thin, long M6 bolt(10mm head) should only be loaded when adjusting belt tension while two front and back M8 bolt/nuts (12/13m heads), are loose.

when the belt tension is correct, tighten the two M8 bolts, locking it in place, and relieve tension on the long M6 bolt. It isn't tight or under load otherwise. Keep it lubed, and it won't break.

I wasn't tightening it wrong...it broke while adjusting because my first belt was to worn that I tried to compensate by adjusting. But I garuntee if the bolt wasn't old/rusted it wouldnt of broken. When I replaced it, I bought a cheap bolt from the hardware store, and about a month later my alternator was dangling after it snapped while driving down the road.

After that, ordered a hex head m6 bolt from mcmaster carr and no problem for the last 6 months. If it breaks, Get a good replacement...
 
I wasn't tightening it wrong...it broke while adjusting because my first belt was to worn that I tried to compensate by adjusting. But I garuntee if the bolt wasn't old/rusted it wouldnt of broken. When I replaced it, I bought a cheap bolt from the hardware store, and about a month later my alternator was dangling after it snapped while driving down the road.

After that, ordered a hex head m6 bolt from mcmaster carr and no problem for the last 6 months. If it breaks, Get a good replacement...

Properly installed, if it vaporizes while driving, nothing will happen.
You are doing it wrong.
 
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