740 belt routing

ccb222 · Post by **ccb222** » 20 Aug 2012, 12:57

1987 740 drive belts being replaced.
When I removed the three (3) belts, I observed that the A/C Compressor belt was routed to the front pulley (of three) on the crankshaft which is out of line by a pulley width with the pulley on the A/C compressor. The belt has never come off, but it doesn't seem as though this is right.

Here's what I've got:
Crankshaft--3 pulleys
water pump--2 pulleys
power steering pump--1 pulley
alternator--2 pulleys
A/C compressor--2 pulleys

All rear pulleys in line.

Belt 1: rear crankshaft pulley=rear water pump pulley=power steering pump
Belt 2: middle crankshaft pulley=front alternator pulley
Belt 3: front crankshaft pulley=front A/C compressor pulley

It's Belt 3 that's the problem.

Routing should be---???

Thanks,
Charles

lummert · Post by **lummert** » 20 Aug 2012, 16:08

Are all of the belts off by one space? If not, check the A/C compressor rubber mounting bushings. If yes, check the crankshaft pulley for slipping. Make certain that you're trying to install the A/C belt on the correct groove on the compressor pulley, I had an alternator belt on the wrong alternator pulley groove and it wore out the belt.

ccb222 · Post by **ccb222** » 20 Aug 2012, 19:51

No, the only belt that's off by one space is the A/C compressor.
Rubber Mounting Bushings of the A/C compressor all (4 of them) are sticking out of their metal housings to the rear for some reason, and it seems, by the 1/2" I need to get the front A/C pulley aligned with the crankshaft pulley.
HOWEVER, if I move the compressor toward the front, it looks as though the brackets for the adjustment of the belt will be misaligned.
Any insight?

Thanks--

lummert · Post by **lummert** » 20 Aug 2012, 21:32

I'm thinking that the adjustment brackets will move forward with the compressor. Of course I would have to check my 88 765 to make certain. My bushings are worn enough that the compressor moved around too much. I learned of the worn mounting bushings when I recently decided to replace the broken adjuster after driving the car more than 6 years without the belt. After 6 years without using the A/C compressor (and no belt installed) the clutch is stuck and won't release.