1990 Volkswagen Jetta Mk2 1.6L diesel, alternator belt drive modifcation

[TheEmy27]

can I please get the part number for the bearings and how long the bolt needs to be thank u

[MercedesDieselGuy]

@TheEmy27 I can't seem to post a link here, so I'm going to send you a message with a link to the forum post that has the part number information.

[compu85]

It's very critical that all the pulleys line up. VW in their wisdom used a myriad of different alternator pulleys, and if it's not lined up just right it puts sideways tension on the belt and snaps it. The belt can also slip because the 2 piece stamped steel pulley wears out. I replaced the one on my ex 1991 ECOdiesel with the updated one piece pulley and never threw another belt. I think the current belt has 25,000 miles on it!

The belt system leaves a lot to be desired. I like this mod!

[MercedesDieselGuy]

@compu85 - Thanks. Actually, it wasn't my design. I got the fix online.

I sold the car around six weeks ago. As the car was leaving with the new owner, the belt did start squealing again. I didn't have enough time with this setup (it was in the car for around a month - maybe 1000 miles) to know if this is a long-term solution or not.

[damac2004]

Are all of this generations diesels supposed to have this problem or is it because of some accessories and the belt routing?

I just have my alternator belt going to crank, alternator and water pump. Got my 85 jetta td used in ok shape and replaced the belt for the hell of it when I brought it home and its still on there 20,000 miles later?

[MercedesDieselGuy]

@damac2004 From what I hear, the really problematic ones are the cars like mine with AC and power steering. Even so, the belt setup is pretty finicky regardless. But, I'm not an expert on these. Sounds like you got one of the good ones, though.

[compu85]

It's very critical that all the pulleys line up. VW in their wisdom used a myriad of different alternator pulleys, and if it's not lined up just right it puts sideways tension on the belt and snaps it. The belt can also slip because the 2 piece stamped steel pulley wears out. I replaced the one on my ex 1991 ECOdiesel with the updated one piece pulley and never threw another belt after that. I think the current belt has 25,000 miles on it!

[Rowburt51088]

hey where in mass do you live?

[MercedesDieselGuy]

@Rowburt51088  I'm in Worcester. How about yourself? BTW - checked out the metal riffs you posted. Pretty good stuff.

[Rowburt51088]

@MercedesDieselGuy thanks man that stuffs really old im gunna post some new stuff.

[V10PDTDI]

would bounce at idle only as soon as the engine would run faster it would go away so at fist we replaced the tensioner with a new one it would be good for a while and then come back like it was so we figured that the TDI never had any problems so we installed the TDI pulley and then bingo fix what this affected is it got the crank gear bolt loose and then would damage the end of the crank and finally it would slip and then bent the valve very expensive alternator pulley problem. seen it lots.

[MercedesDieselGuy]

@V10PDTDI Thanks for the feedback. So far, this fix is working out well (close to 250 miles already).

[V10PDTDI]

Great tip I all know what you are talking about I not only owned these cars bu woks on them we own a vw shop and I sorry to say but I'm glad we don't work on them much anymore I was so glad when the 1.9 TD came out with the serpentine belt set up but the only problem with the 1.9 TD was the factory alterator pulley was fix what I mean is the the first Jetta and Passat TDI came with a clutch pulley like the ALH MK4 TDI and at idle when the black belt tensioner came soft then at idle the belt

[V10PDTDI]

Great tip I all know what you are talking about I not only owned these cars bu woks on them we own a vw shop and I sorry to say but I'm glad we don't work on them much anymore I was so glad when the 1.9 TD came out with the serpentine belt set up but the only problem with the 1.9 TD was the factory alterator pulley was fix what I mean is the the first Jetta and Passat TDI came with a clutch pulley like the ALH MK4 TDI and at idle when the black belt tensioner came soft then at idle the belt