Crankshaft?

Do the AHU and ALH engines use the same crankshaft?

No, they are a totally different engine family from one another.

They are similar, and have some commonality mainly in the arrangement of the cylinder head and bore spacing, but that is about it.

Thanks for the straight scoop on the crankshafts.

I've heard that the pistons and rods are the same. Is that so?

If you have used a Fluidamper harmonic balancer, what's your opinion of it?

The ALH still continued to use the 028 type con rods, yes, but the pistons are an updated 038 version but you can put ALH pistons in an AHU.

I have no experience with the damper you speak of, but have heard of them.

I assume the context to your question is that your AHU's crank snout is ruined. I think this is a weak point of that engine, which was in 1998 already a design dating back to 1974. This was remedied with the ALH.

But, I think making sure the crank bolt is kept secure, the alternator clutch pulley is in good order, and the balancer is the newer type, can at least give the AHU a good long service life.

No problem with cranks or balancers. I have a 98 Jetta with about 130 k on a 1Z engine that runs well. No mods.

Just nabbed an 03 Jetta TDI with bad clutch, maybe flywheel too. Have serviced my own cars for years, but will need to get the tools to change the T belt on this one. Much more work to get at and change the belt than in the older ones. What's the diameter of the pin for the injection pump sprocket?

Except for the 2,000 miles between us, I'd have you do the timing belt job .

Thanks for any info you're willing to share.

I would just buy the tools necessary for that job, they are not expensive.

The cam lock plate is different, although there are some that work on both type engines.

The ALH pump lock pin # is 3359. I have seen them on eBay for as cheap as $12.