TheSamba.com :: View topic - 82 vanagon diesel alternator/water pump belt

Sat Jul 26, 2014 4:53 pm

am i supposed to use one belt from the crank to the water pump and another one from the water pump to the alternator? my alternator stopped working and i found the snapped belt, so i bought a new one exactly like it. i found that it went from the crank, around the water pump pulley and onto the alternator pulley. but it squeals and i think it's because i need a seperate, smaller one that goes only from the water pump pulley to the alternator. is this correct?

Sat Jul 26, 2014 6:38 pm

The stock 82 diesel pulley setup uses 2 belts. One from the crank to the waterpump, 643mm, another from the waterpump to the alternator, 600mm.

Mark

the bard wrote: am i supposed to use one belt from the crank to the water pump and another one from the water pump to the alternator? my alternator stopped working and i found the snapped belt, so i bought a new one exactly like it. i found that it went from the crank, around the water pump pulley and onto the alternator pulley. but it squeals and i think it's because i need a seperate, smaller one that goes only from the water pump pulley to the alternator. is this correct?

Sat Jul 26, 2014 6:42 pm

Yes, there are two separate V-belts: one from the crank to drive the water pump, and another from the water pump to in turn drive the alternator. If you only broke one belt, you should still see the remaining intact belt.

They're different sizes:

Water Pump
10 x 643mm

Alternator
10 x 600mm

The double pulley on the water pump utilizes a dodgy system of stacked shims which you add/delete in order to achieve the proper tension on the crank-to-water-pump belt. The alternator belt tension is easily adjusted in the typical fashion, using an adjustable mounting bracket.

Good luck!

Sat Jul 26, 2014 7:01 pm

Possibly not relevant but my AAZ 1.9 has one belt that drives the alt and WP

Far from a stock engine - even a stock AAZ

Sat Jul 26, 2014 7:03 pm

thanks for the response(s). so do i have to remove the water pump belt to get a new alternator belt in there? also, how exactly does this 'dodgy' shim system work?

Sat Jul 26, 2014 7:09 pm

that's what one of my belts does too. (the one i just replaced) but i have another one from the crank to the water pump. so, in essence, i have two belts 'driving' the water pump pulley and i can't imagine they are spinning at the same rate which probably isn't good. thanks for the photo. i'm just learning how to post so someone with the knowledge to post a photo is at a whole other level. :)

Sat Jul 26, 2014 7:48 pm

I object to the use of pejorative terms like "dodgy shims” to describe the belt adjustment system. These assertions just poison a newcomer’s experience of the diesel Vanagon. I have found the shims to be extremely reliable and simple, while keeping moving parts to a minimum.

Obviously the water pump is critical, considering the isolation of the engine from the radiator. The shim system is well engineered to keep the pump turning by avoiding an unreliable adjusting bracket and idler.

There is some mechanical ability needed to adjust the belt properly, which some have trouble with. They then launch into a lifelong crusade of badmouthing the offending shims while others defend the maligned shims. I am obviously one who is pro-shims, so let the vituperations begin.

If you remove all bolts, it can be tricky to align the outer sheave and shims with the bolt holes. I use a small tool to align the holes prior to inserting the bolts, it is easier than trying to insert the firt bolt through multiple unalighned layers.

For a new belt, which is smaller in circumference, put more shims between the sheaves. This spreads them apart causing the belt to ride lower between the sheaves. As the belt loosens up, maybe after a few thousand miles, remove a shim and store it outside directly under the bolt heads.

Seems pretty easy to me.

Sat Jul 26, 2014 8:20 pm

as a newbie, i'm (hopefully) assuming the sheaves you are referring to are the ones on the water pump pulley(s). and i gather - from looking at my setup - that there are extra shims on the outside of the pulley.

so here's one more question. i just need to replace the alternator belt. but i suppose i have to take off the water pump belt to get it on. and thus, the shim/sheave/pulley shuffle......?

am i making sense?

Sat Jul 26, 2014 8:41 pm

Yes, you are making sense. A pulley consists of two “sheaves” that are normally affixed to each other permanently. In the diesel Vanagon they are in two parts adjustable between them. The distance between the two sheaves determines the tightness of the belt. More spacers means a smaller belt. Remove spacers as the belt expands and store them on the outside of the pulley.

Yes you’ll have to take off the alternator belt to get the water pump belt on. As I recall, it is easier to do this job if you remove the license plate holder with a phillips head screwdriver. Just gives you more access to the pulley and will save you time.

Sun Jul 27, 2014 5:32 am

thanks to everyone who responded to my alternator/water pump belt queries. time to use some elbow grease and give this a try. gotta love the samba.....

Sun Jul 27, 2014 9:32 am

OOPS, I had to change my own alternator today (to put in the tachometer compatible model) and what did I notice? That you can change the water pump belt without taking off the alternator belt, but not vice-versa.

I don’t need to change the alternator belt, so it is a slip-on exchange. Maybe other diesels are different from mine.

Sun Jul 27, 2014 2:25 pm

Rest assured, I have no intentions of directing any "verbal abuse or castigation, violent denunciation or condemnations" regarding this matter, nor embarking upon a "lifelong crusade" of any sort. I mean, they're just shims ... Sigh.

The OP will undoubtedly find his own reasons to love or despise the diesel Vanagon. After many years of ownership, I personally appreciate mine enough to have recently replaced the tired original 1.6 with a new 1.9. But my appreciation for her elegant simplicity doesn't blind me to her few minor flaws, including a V-belt setup that's somewhat fiddly to adjust.

I understand WHY this particular belt arrangement is needed in the Vanagon, but that makes it no less difficult, especially when I'm doing the old Shim Shuffle through an opening barely the size of a large index card, with the engine snug up against the rear frame member to accommodate a 5-speed transaxle. And if not quite right, repeating it all again ...

To the_bard: just to clarify, NONE of your belts should follow the path of that shown in the photo of the AAZ 1.9 above! As Gizmoman says, his AAZ is pretty seriously modified and uses a completely different belt arrangement. You should indeed use the stock Vanagon diesel V-belt setup; besides ensuring the proper rotational speeds for water pump and alternator, the stock setup also has the added advantage that the primary drive belt contacts about 50% of the water pump pulley circumference, for a good no-slip connection.

Good luck!

Sun Jul 27, 2014 3:38 pm

My pic was showing that a single belt set-up can be accomplished - not recommending it (not offended, just bringing clarity). If mine had shims (like my old 1300 bug did), I still might consider doing something else for the reasons posted regarding access. On the bug they were right there. In the van, not so much.

I have always been concerned about the minimal contact of the WP pulley so, just check the belt tension when doing routine oil and water level checks.

Sun Jul 27, 2014 3:47 pm

Jeffrey Lee wrote: they're just shims ... Sigh. Yes, they are just shims, no reason to get in a fistfight over them. I even have the 1.9 with 5-speed, so I know what you are saying about the fiddly space.

Truth is, I have only had to adjust mine once in 100k miles and that was when I put a new belt on. The system may take more patience than average, but the amount of maintenance it needs seems to more than make up for it.

Sun Jul 27, 2014 5:13 pm

My 83 diesel Vanagon has one belt for both. Are 83s different in this way, or did mine get changed in this area when the van got an engine swap from an 85 jetta diesel by the PO?

Sun Jul 27, 2014 5:13 pm

My 83 diesel Vanagon has one belt for both. Are 83s different in this way, or did mine get changed in this area when the van got an engine swap from an 85 jetta diesel by the PO?

Sun Jul 27, 2014 7:00 pm

Yeah Gizmoman, I understood that, but thanks for clarifying for the benefit of the thread ... Sweet build, BTW; have you run it yet, or still buttoning it up?

FWIW, I've considered putting together a similar pulley setup but never got round to it. And as Gnarlodious says, the stock setup seldom needs adjusting. Fortunately.

bugeye72 wrote: My 83 diesel Vanagon has one belt for both. Are 83s different in this way, or did mine get changed in this area when the van got an engine swap from an 85 jetta diesel by the PO?

bugeye72, all years of the Vanagon diesel use the same pulley setup. For reference, here's what the bone stock original 1983 1.6NA "CS" Vanagon diesel looks like, in all its sooty glory, with the pulley end clearly visible. The crank pulley drives the water pump, which in turn drives the alternator. The center, water pump pulley is the one requiring adjustment using the integrated shims.

I can't say whether a Jetta diesel would use one belt or two. Every *gasoline* VW car I've owned (nearly identical engine layout to the Vanagon diesel) has used one common belt to drive both water pump and alternator, similar to Gizmoman's setup above. As have most other cars prior to the widespread use of modern serpentine belts.

But as Gnarlodious points out, it's possible VW felt the Vanagon's rear-engine design warranted a more secure water-pump drive, hence the dedicated belt. Since this would NOT be the case on a front-engined Jetta, maybe they used a single-belt arrangement? Only speculating ...

Sun Jul 27, 2014 7:38 pm

The crank pulley, like the water pump pulley, is DOUBLE, with TWO grooves, though the innermost groove is unused in the stock configuration. The WP belt runs in the outermost groove, as can be seen in the identical 1.9NA pulley setup.

The inner groove is *close* to being aligned with the WP inner groove and the ALT pulley groove. It's possible that a previous owner found the correct belt setup to be too fiddly — as previously mentioned :wink: — and decided to instead cobble together a much longer single belt somewhat similar to Gizmoman's but WITHOUT his proper alignment.

This misaligned belt setup may work for awhile, but would likely prematurely wear the V-belt, leading to a cooling failure, possibly catastrophic in a rear-engined Vanagon.

The proper belts should be installed on the correct pulleys.

Sun Jul 27, 2014 7:51 pm

bugeye72:
Can you identify what engine that is? Someone might have put a 1.9NA engine in that van. That would be a sweet deal…

There are usually some numbers cast into the exhaust side of the block that tells the liters.

Sun Jul 27, 2014 9:09 pm

Gnarlodious, how are you liking your 1.9? Is it an NA or a turbo? How long have you had it?

I only have about 1000 break-in miles on mine, but so far I'm a bit underwhelmed by the performance. At 67 HP, I was frankly hoping for about a 30% improvement in performance over the anemic stocker, but don't feel I'm getting it yet. Did yours improve after break-in?

Appreciate any insights you have!