AC and alternator belt help plz!

[bbob203]

Here's my solution a gates 10x675 for alt and a gates 13x955 I think it is. I replaced stock idler with a timing belt tensioner on same adjustable system as the old idler. I used a few jam nuts on the adjusting bolt to hold it in a fixed postion whilst still being able to adjust the idler tension. no real miles on it yet but it is smooth at idle in my garage.

[92EcoDiesel Jetta]

............................................
I test this setup for a year; in the warm weather it was fine,  but I found in the cold weather, the lugs would rip off the belt, so it is running stock for now.




More puzzling, is the stock system on my '89  works pretty well.

I wonder if a non lug belt will work better?  No lugs to shed.

[DogDiesel]

Mine is an idler pulley slightly larger, but the same concept. Belt bends are not as drastic as with the pulley in your picture.

Quote: From Tyler.  "Like this?"

[92EcoDiesel Jetta]

Here's my solution a gates 10x675 for alt and a gates 13x955 I think it is. I replaced stock idler with a timing belt tensioner on same adjustable system as the old idler. I used a few jam nuts on the adjusting bolt to hold it in a fixed postion whilst still being able to adjust the idler tension. no real miles on it yet but it is smooth at idle in my garage.

I like it! How are you pushing the roller into the belt? Let us know how this works out in the long run. Changing alternator belt is still a PITA. How long does it take you? The first time took almost a whole day. I can do it in under 1 hour now provided I have the right tools ready, including a remote starter switch.

Crazy to have to spend 1 hour to change a belt requiring so many tools (the right bits and extensions and ratchet/breaker bar, flex head gear wrench)

[92EcoDiesel Jetta]

I had this belt system on my previous 1.9AAZ build, it came from MKII.
 Like you, my alternator belt flopped and loosen and I rarely ever go over 20K miles before replacement.

Then I created a counter pulley.

I took a longer bolt on the back of the ALT BRKT under the INJ pump and threaded the shank to match the OEM bolt, then shaved the threads where it came out of the mount.  Then I took a small 2" pulley with bearing that I bought from a lawn mower shop, shaved the outside edges to fit the area without rubbing, put it on thus geting more belt contact with the pulley.

My belts stopped flopping, they lasted.  My voltage came up, obviously the OEM setup had slippage, and with more pulley contact my slippage was nill.

I pulled that engine and put in another AAZ with serpentine.  Love it.  Sweet.  Still have that counter pulley in my shop.

Wayne

Do you have a pic of your setup?

[DanV990]

This is what I've done on my 1992 ECOdiesel to delete the AC & power steering and use just one belt for the water pump and alternator. So far I have had absolutely zero belt squeal or slipping
The engine and alternator bracket are from a 1983 MKI Rabbit. The alternator is from the '92 ECOdiesel Jetta. I sleeved the lower bolt hole on the MKII alternator with aircraft grade aluminum so it would mount on the MKI bracket that uses a smaller bolt diameter. I then went to the local alternator shop and found a pulley that has a longer offset so the alternator lines up with the water pump and crankshaft pulleys and fits the wider 12.5/13mm belt. I also put a couple of bearings and a long spacer on a bolt that holds on the lower cover for the timing belt to help tame down belt slap. The belt is a Gates 9485 Green Stripe XL 13A1230
I may add another set of bearings to the bolt for the lower alternator mount to tame down the rest of the belt slap.

Total cost of this modification was $27 plus bits and pieces (nuts, bolts, washers) I had laying around my shop.

Extended pulley  $10
13A1230 Belt     $12
Two Bearings       $5


Here are a couple of videos of it running followed by a few photos

http://www.youtube.com/watch?v=0St3RiqIuIE

http://www.youtube.com/watch?v=EQXO-gXpDeU

[hillfolk'r]

Ok I grabbed a bunch of belts tonight from my job. I'm trying a 4L 280. My alt belt is doing the  same thing. In fact it's so bad I gotta hold a high idle with the lights on. I know the  stock belt is 10 mm so I figured on trying a 11 or 7-16. I only put it on tonight, and it sits proud in the  ac and idler but nice in the alternator. Time will tell. But so far I didn't have to tension it again after driving home. Like I said time  will tell if a fatter incorrect belt will work.

Not the greatest pic but its high on the ac and tensioner and almost perfect on the alt


And while I was tinkering,for good measure
I basically backed out the idle screw then adjusted the idle with the fuel. Nice and goody sootyvag

[hillfolk'r]

A fatter belt may be better. I know its only been a few days and i retensioned it once but it wasnt loose enough to squeal. Yea time will tell though. It may not be the real fix or its a halfarse repair but hey if it works it works.
I ran this problem past guys i work with cause they deal with motors and belts and pulleys and thats what hey are sort of thinking that a stock 10mm belt isnt wide enough to carry that much load maybe.

[92EcoDiesel Jetta]

I tried the fatter belt (1/2 inch) and it is not a permanent fix. As it wears the belt gets grooved and quickly go downhill from there.

[R.O.R-2.0]

I tried the fatter belt (1/2 inch) and it is not a permanent fix. As it wears the belt gets grooved and quickly go downhill from there.

1/2" (13mm) is too wide for a 10mm pulley..

7/16 (11mm) shouldnt be too much of an issue tho..

[hillfolk'r]

So far so good with the wider belt. I only tensioned it again the next day after install and its been a week+ and it hasnt lost tension yet. Im not worried if its correct im just happy that i can pull up to a traffic light and dont have to shut off all th electrical consumers until i get goin again

[R.O.R-2.0]

So far so good with the wider belt. I only tensioned it again the next day after install and its been a week+ and it hasnt lost tension yet. Im not worried if its correct im just happy that i can pull up to a traffic light and dont have to shut off all th electrical consumers until i get goin again

your runnin the 11mm belt now, right?

[hillfolk'r]

Yea. It sunk a little requiring some adjustment but i figured that was gonna happen.
It definately needs or has needed less adjustment than a normal one.
Yes it  bounces and looks crazy when its idling on the wide span. It may sink a little more in one of the pulleys i havent really looked close.
i just been enjoying driving it and not worried about what electrical consumer i can have on.
Lol i even jump started my cousins car and it still didnt gimme a problem yet. I did retension it a little the other night but if it was the old belt i woulda needed a few retensions since then.

I dont get it, what is the real underlying problem? Even when i got it in 03 it didnt eat belts.
I thought i saw someone here did change all the pulleys related like the ac clutch and tensioner/idler,and still doesnt like it.
Oh if your idler pulley is fair you can press a new bearing in for 15$ vs like 80 for a new assy(thats about the price i saw)

[wolf_walker]

I've been fighting with v-belt problems on these things forever.  And by forever I mean since I started driving them in, 1990 or so I guess.  Every one.
The least problematic was an 86 8v gasser with AC and no PS, the diesels are more troublesome for whatever reason.

I have observed that belts are often not the stated, or correct, size these days.  Most of my stuff does not take a stock size belt any more so I can't remember anything specific, but
I've had the problem with Porsche as well where spec is xxmm width, and they substitute xx.xmm width since it's handy.  It works, but isn't ideal.

I've had good luck cleaning the crap out of pulleys, degrease, scotchbrite, clean up on oil changes without removing belts.

I try real hard to not over-tighten belts, it's counter intuitive. 
The alternator, the worse shape it's in or the more heavily loaded it is for a given amparage, the more likely it is to squeal it seems.
The AC pump chirps at idle when the AC is on running high pressure with R134, I don't remember any of them doing this with R12
but it's been awhile.  I've seen this behavior in other cars as well. 
I've never had what I thought was a slipping water pump belt so far, fwiw.

I replace them often, and keep a spare.  Belts are cheap, and don't buy cheap as in crappy belts.  Contitech belts aren't what they used to be.

I never liked the way the alternator belt flaps at idle, most of em do it.

Pulley alignment and size is important, a lot of that stuff has been swapped around over the years.  Manufacturing tolerance in water pumps, and
differing water pump pulleys are a factor as well.

That's all I got, I can manage the problem, but it's still there.  I've only ever thrown one belt.  I keep an eye on them, every fuel stop.

[92EcoDiesel Jetta]

Same here, fighting the alt belt (with AC) forever. It's insane the amount of time I spent fighting the alt belt. It's a bad design:

1. poor belt tensioner routing- less belt contact as the tensioner is tightend.

2. too narrow a belt for the load (90 A alt w AC)

3. alt belt is immensely difficult to replace. Took me 8 hours the first time

There are a few people on the forum who have no trouble with the alt belt with AC. Maybe the pulleys on those cars are perfect.

If you have AC and intend to keep it, then I'd suggest replacing the 3 pulleys on the alt belt with new ones from the dealer. Are they available? Probably not cheap.

If you don't need AC, the best solution is deleting the AC compressor and its tensioning bracket, lower the alt into the AC compressor's space, replace the alt's 10 mm pulley with a 13 mm double pulley and run a 13 mm belt off the AC pulley on the crank.

I have such a setup and and so far no problems with the belt loosening up. Changing alt belt now takes a few minutes instead of hours. Swapping the alt  takes 15 minutes.