Alternator belt broke--how to replace?
 

Well I got the HVAC on my car running, and when I turned it on for the first time, I heard some squealing sounds. At first I thought it was the HVAC blower motors finally coming on after a long slumber, but then the noises stopped and I decided to go for a drive. Then the tach started going wacky and my headlights were very dim!

Then the car just flat out died and I got out and smelled burning rubber and the alternator belt had just completely torn. I'm guessing running the HVAC put additional load on the alternator, which made the pulley harder to turn and caused the belt to slip. (Does that sound feasible? My friend insists that no matter how much load you put on the electrical system, the alternator is always freewheeling and that my theory is impossible!) Apparently the alternator belt has broken before by the previous owner (perhaps a couple years ago?) but I checked the pulleys and they do look like they are properly aligned, at least with a quick visual inspection.

Back on topic...

How do I replace the alternator belt? I know there is a locking bolt on the alternator and a tensioner, but there are two other belts in the way, and they look like a big pain to get off. Are there any tips for doing this job (removing the other two belts blocking it in?). Do I need to remove the fan?!

Don't need to remove the fan.

Of course if other belts are blocking, they'll have to come off first. I can't remember the order of the belts on a Ser III

On any of the belt driven devices you'll have to loosen the pivot bolt a bit before using the turnbuckle-style adjuster

I recall that, in some cases, the adjuster might have to be disconnected at one end to allow the alternator (or whatever) to swing far enough to get the new belt on

Hope this helps a little. It's been too long ago for me to give a bolt-by-bolt description

Cheers
DD

does the alt belt drive the ac compressor, too? Remember this is an automatic climate control system, so I'm thinking maybe the compressor took the belt out as the squeeling and belt breakage coincided with the bringing back to life of the hvac system. THe ac amp can turn that compressor on whenever it likes.

I don't believe that the AC belt and the alternator are on the same belt. The AC belt still appears to be connected.

I carefully worked my way through the factory service manual and I think I have an idea of where the pivot bolts are for the power steering pump, the AC compressor and the alternator. I'll give it a shot!

If the battery is low and/or there's a large amperage draw (like a/c compressor, rear defogger, blower motors all on at the same time) the alternator will be under a greater load. A loose belt could slip, and an almost-ready-to-break belt could conceivably be put over the edge.

Cheers
DD

I was also thinking along the lines of the compressor might be seized or close to it and replacing the amp, turning on the hvac engaged the clutch (thus the subsequent squeeling) and took out the belt.

Well, I had to give up. The good news is all the belts seem to have been very IMPROPERLY tensioned, they are all very loose. I'm surprised they're not all broken already! Pushing down on them lightly (maybe 5 lbs of pressure) resulted in the belts deflecting about an inch. It wouldn't surprise me if the alternator belt were done the same way.

I cannot for the life of me figure out where the damn AC compressor pivot bolts are. I have loosened the bolts on the tension adjuster and the two nuts on it, but I can't figure out where the pivot bolts are! Does anyone have any idea where they are?

Wouldn't that imply that the compressor belt would be the one that went out? The compressor belt is not broken.

Does the belt for the alternator drive it alone, or something else as well ? On my UK car, which had no Air Con, it also drove the water pump.

Check that everything your broken belt drives rotates OK, and is not seized.

Yup, the alternator belt drives the alternator alone. The alternator spins freely. Does anyone have any idea where the pivot bolts for the air con compressor are? I just can't find them!

Any ideas? :) The FSM says there should be a rear pivot bolt and a front one--but it does a poor job explaining where they are.

I've attached a picture of an aircon compressor off Ebay that I think has a good view of both sides of the compressor. I'm having trouble figuring out how it pivots!

http://i.ebayimg.com/t/NEW-AC-COMPRE...qLQ~~60_12.JPG

Here's another view! I imagine if there's one bolt on the front and one on the rear that need to be loosened in order to pivot, they both need to be on the same plane. I just can't seem to see any holes that are on the same plane on the front and the back!

http://i.ebayimg.com/t/A-C-Compresso...(V!g~~0_12.JPG

One more!

Is there no jockey pulley to tension the belt ? If not, then compressor will have to be mounted on a bracket with some sort of relevant adjustment facility. There seems to be nothing on the pics of the compressors.

As I remember it my alternator pivoted on two lower lugs, and an adjuster at the top allowed belt tension to be adjusted.

If you have the workshop manual, it should show belt layout.

Yeah, the compressor belt has a tensioner towards the top, but I'm trying to figure out which bolts I need to undo.

I guess i'll just give it another shot when it gets warmer out--but there's so many nuts/bolts on that thing I don't want to disconnect the wrong one! I also don't know which way it's supposed to pivot (down? inwards?) and I don't want to break or bend the tensioner.

https://lh3.googleusercontent.com/-1...eltRemoval.JPG

https://lh3.googleusercontent.com/-M...movalRefit.JPG

This is what I have to work with. The alternator drive belt removal instructions make it sound like there's two bolts that need to be slackened (so do the compressor removal instructions), but only one bolt is labeled on the diagram.

OK, I think I've figured it out. I've circled the ones I think need to be removed.

Notice that that one in the rear has a bit of a longer thread on it and is lined up with the other hole which I've circled. The compressor in the photo is actually upside down.

Just reporting back--it turns out the two I've circled there ARE the pivot bolts. I've been able to get the bolts loosened and the compressor pivoted partially. Unfortunately, the nut on the tensioner is very hard to loosen because it is up against a bracket that holds the compressor to the cylinder block. So I can't get a wrench in there easily to turn the damn thing!

Almost there, though. Slowly but surely! I loosened the bolts holding the tensioner onto said bracket and the compressor, and I'll probably wedge a screwdriver in there to separate the tensioner bolt from the bracket just enough to let me loosen that nut.

I am afraid that when Jaguar engineers designed things, the design team did not include a maintenance mechanic. So there was nobody to say " hey guys, this will be impossible to fix the way you've placed it"!

It was even worse, there were no production engineers on the team, the complete design was thrown over a wall to 'production' to sort out how to make it.