Timing Belt V6 TDI: Replacement & Installation

After many other pleasant discoveries, I've now noticed that my pump belt is misaligned. The wheel on the pump is positioned about a millimeter further forward than the front wheel.
The pump is brand new, original, with the same part number, and so is the NW (presumably a related component). How can this be? Of course, I didn't pay attention to this before starting the extensive replacement procedures.
How can that be? Are there different types of NW wheels?
I'll probably have to put three large washers between the two NW wheels.

I need to check mine, but I don't think I would have normally noticed. Is it only partially running on the impeller?

Due to the washers, the alignment of the second wheel is not achieved through the screws. I'm worried that you won't be able to properly position the washers (they won't lie flat) and that the wheel will become misaligned.

"Could you possibly move the pump a bit further back, or have you forgotten something? The fuel injection lines would barely be able to handle that. I think that's the better solution."

Hello.

Okay, if the belt is running completely along the full width of the pulley and isn't rubbing anywhere, I would leave it as is. That's definitely better than messing around with shims.

Greetings!

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I've now noticed that my pump belt is running crooked. The wheel on the pump is positioned a good millimeter further forward than the NW wheel.

If there's a genuine misalignment, the belt should wear away on the vibration damper or tensioner on the side due to the friction (measure the belt width). If that's not the case, it simply means the pulleys are offset relative to each other, which, as R.M. writes, isn't a problem as long as the belt is fully seated.

The squealing only occurs when the pump is positioned too far back; in this case, it's the opposite. When that happens, it runs against the limit of the counterweight wheel on the front. As far as I remember, the tensioner pulley is smooth and doesn't have any "limitations." Therefore, I don't think the belt is hitting anything. At most, it might not be fully engaging with the pump pulley.

It's not really a big deal if the belt breaks, but something was still done on a large vehicle. I suspect the pump was mounted too far forward, or there's some other difference. I don't think using washers on the pump mounting is a bad thing, as long as the fuel lines don't experience excessive tension.

Today I looked at it (great attachment of the cover , probably not possible to remove and install without scratching your hands). The belt is straight, the pump should be positioned further back, but I've never removed it before...

The belt tension is determined by the spacer sleeves, and there's nothing you can do about that. The belt is rubbing against the axial guides, and the cover is visibly worn and dirty. If I wait a while longer, it will probably resolve itself; the belt will just be a bit narrower than normal. The best way to prevent problems during assembly is probably to lightly glue the washers to the edges. Centering is probably still within 1 mm.

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The oscillation occurs only when the pump is positioned too far back; in this case, the situation is the opposite.

Okay. So, either the camshaft gear needs to be moved forward, or the pump needs to be moved backward. In that case, will the belt still run centered over the tensioner pulley?

Is the pulley installed correctly on the pump? If it's asymmetrical, it's possible that it's mounted upside down, right?

The tensioner still has some play. The pump impeller must not be disassembled; only the flywheel at the front can be removed.

@christians
Is it now that the impeller only partially engages with the pump wheel at the back, or does it engage with the Northwest wheel at the front and hit this limit?

@BM
The tensioner pulley is slightly wider (probably >1mm) than the belt, but I don't see this as a problem. Especially because I think the position of the tensioner pulley relative to the crankshaft pulley is correct.

The left-side (NW) wheel that drives the belt is difficult to turn. The screws that secure it have elongated holes (resulting in play). A flange on the left-side (NW) wheel of the drive belt centers the pump pulley, preventing it from wobbling.

Either the large northwest wheel is worn out on the inside, causing both wheels to be positioned too far back, or the problem lies with the pump. The former is less likely (the main timing belt would also have to be misaligned), while the latter is more probable, as he only noticed the issue after installing the new pump.

The VP44 is screwed onto the "engine" from the rear, so you don't have to remove anything from the pump mounting to access the rear; you just need to fill it. Since the alignment in the longitudinal direction of the vehicle remains unaffected by the same washers, and the alignment around the pump axis is irrelevant (keyword: adjusting the dynamic start of injection), I consider this the best solution. If any adjustment is even necessary...

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The pulley is slightly wider (certainly >1mm) than the belt, but I don't see a problem with that.

I'm not entirely familiar with the motor, but if the tensioner pulley is rounded (?), which would center the belt, that wouldn't be an ideal solution either.

Update: I just removed the cover again. The impeller only has a guide on the front; the belt is not guided on the back. It runs against the crankshaft pulley on the front, which means that the axes of the two shafts are not perfectly parallel, or the axis of the tensioner is not aligned with the rest.
There's not much excitement to it.
The "starting disc" of the sNW wheel had a bulge, which might explain the wear.
Anyway, the issue with the washers has definitely been resolved.

I should have looked more closely from the beginning.

christians wrote:

1) The axes of both pulleys are not perfectly parallel to each other, or the axis of the tensioner pulley is not parallel to the rest of the system. 2) Well, that issue with the washers has definitely been resolved.

"I thought you might have had parallel waves, but the wheels were positioned at different distances along the longitudinal axis... When I say 'not parallel,' I mean the ESP (Electronic Stability Program) is likely installed at an angle."
2) But should shims be placed between the crankshaft pulleys? How thick are these shims, and is that enough for proper alignment? If the shafts are not parallel, wouldn't the timing belt still "climb" (rub against the limit) despite the lateral offset?

Herr Antje wrote:

christians wrote: 1) The axes of both pulleys are not perfectly parallel to each other, or the axis of the tensioner pulley is not parallel to the rest of the system. 2) Well, that issue with the washers has definitely been resolved. "I thought you might have parallel waves, but the wheels were positioned at different distances along the longitudinal axis... When I say 'not parallel,' I mean the ESP (Electronic Stability Program) is likely installed at an angle." 2) But, are there any

spacer plates between the NW wheels? How thick are these plates, or is the thickness sufficient for proper alignment? If the shafts are not parallel, wouldn't the timing belt still "climb" (rub against the limit) despite the lateral offset? }
I thought so too, but I hadn't looked closely enough. "Not parallel" doesn't mean "completely crooked," it's probably not much, but it's enough that the belt runs on one side. I probably overestimated it because of the wear.
The pump cannot be installed incorrectly due to the bushings, but perhaps the front NW bearing is slightly worn, or it might just be normal, and I'm being too particular.