AAZ crank bolt problem?

[MadCityMike]

Just bought a 94 Jetta w/ 1.9l TD and have been reading about the crank bolt issue.   The previous owner said the timing belt had recently been changed so I'm concerned about the crank bolt.    I was just outside looking inside the engine compartment with the engine running and noticed that the crank pulley is wobbling really bad.    Is this indicative of the bolt coming loose?   I'm going to go out and see if the bolt needs tightening right now, but I've been reading that there's a "proper" procedure for tightening it and that it requires a special tool.    Can someone please elaborate?  

Mike

[wyldman]

If it's already wobbling,it's probably to late.Tightening( the crank bolt if it's loose,and the crank gear has moved) may crack the crank.The easiest way to see if it's moving is check the belt timing.If it's off,then it's coming loose,or is moving.

The bolt doesn't always have to come loose to have the crank gear problem.Sometimes the gear and\or crank will just wear,and it spins.

Either way,your best to haul it apart and look.If you don't find anything,then use some loctite sleeve retainer on the crank gear (use a new gear),and install a new bolt correctly torqued with red loctite.That will hold it for a while until you can do it properly.

To torque the bolt,you need a tool bolted to the crank gear to prevent it from turning,and then use a long torque wrench.

[MadCityMike]

Thanks for the reply.   Now I have a ton of other questions, so please bear with me.  

I tried tightening the bolt, but it didn't budge.    I didn't try to apply a lot of torque, but it doesn't appear to be in any danger of just spinning out.

What's the easiest way to check the belt timing?   It starts and runs great.   RPM's don't bounce around at all during idle.   This motor has 397000 km's on it in case that makes any difference.  

If I get a new old style gear, what is the procedure for getting it on the crank properly if using the bolt to cinch it down can crack the crank?  

I've read some posts about replacing the timing belt that mention locking the IP and cam gear.    Do I need to essentially follow the procedure for installing a new timing belt to replace the crank gear, or is there a way to keep everything else lined up whilst replacing the crank gear?

Once the new bolt is torqued down correctly, would it be of any benefit to tack weld it to the pulley?   Just enough to essentially keep it from loosening, but easily grindable for the next time it has to come off?

I've read a number of posts about machining the crank for the TDI style gear, but I haven't seen any mention to the importance of where the flat spot gets machined.    Does it matter what clock position on the crank the flat spot gets machined?   Also, this is more just wishful thinking, but I don't suppose the mod could be done with a angle grinder applied very slowly and carefully?

Also, any suggestions on a makeshift way to keep the crank from spinning while tightening the bolt?

Whew!    Sorry for the barrage of questions.

[Tusker]

Mike,

To put the new-and-improved crank pulley on, you have to get the nose of the crank machined to fit the different style pulley. Here is a write-up on what is involved.  (EDIT: Oops, for got the link.  Thanks Otis 2  :oops: )

I have read that the stock harmonic balancer design is poor on the 1.9 td, and that there is a new upgraded balancer that, along with a new upgraded pulley bolt, can reduce or eliminate the wobbling and be at least a partial fix.  The part number I could find for the upgraded harmonic balancer is 028105243T  I bought one but haven't installed it yet.  It looks a LOT better than the old one.  You might want to try that and see what you get.  If it were me, I would consider the crank and new gear if the new balancer didn't make it smooth out completely.

HTH.

[Otis2]

Have a look at this thread:

http://www.vwdiesel.net/phpBB/viewtopic.php?t=2771

[ibmserf]

I'm just wondering how necessary it is to get this done if there's no wobble.  I have a '97 with 150,000 on it...I know a guy who put 600,000 on his 1.9 and just made sure to change the bolt.  I mean, what is the likelyhood?

[QuickTD]

The likelyhood of a failure is 100% if you do nothing. Normally the failure will occur between 100000-200000km. If you change the bolt at every timing belt change I would guess that the failure rate would be cut in half. Most dealer serviced cars get this treatment, but many still fail. If you change the pulley and bolt at each timing belt change and it was never allowed to get loose in the first place, I would guess that the odds of a failure fall to near zero. The installation of a straight harmonic balancer and a one way alternator pulley help even more.

 Mine is still stock at 295000km. I certainly have the technology to modify it, I've done many, but changing the pulley and bolt regularly is easier. I bought the car with 80000km on it and have stayed on top of the pulley issue.

 I would remove the pulley and inspect the crank nose. If it shows signs of wear, get it fixed, you'll thank your self later. If it looks good, install a new pulley and drive it until the next timng belt change.

[ibmserf]

Thanks for that.  I planned to expect it forsure...but I don't have the know how or the money to take out the shaft and send it away to get machined.  Can anyone recommend where I can find these parts?  It's for a '97 Jetta 1.9L TD.
Cheers!

[wyldman]

Where are you located ? I can get you what you need at a good price.

[ibmserf]

I'm in St. Catharines...I think I'll be looking at getting the belt, pulley, and bolt.  Could you email me the prices for each?  And how much would you charge to do it...I think I've got a friend to do it...but I'm just curious.  Email me at [email protected].

[wyldman]

I'm pretty sure you emailed me earlier on this.

I'll just reply again to that email.

[ibmserf]

Sorry...I just meant for the pulley, bolt and belt...
One more question...does anyone know if the 97 has a tdi crank on it?  and does this mean that i won't have to worry about it?
Thanks in advance for your time.

[wyldman]

No,it will not have a TDI crank.The only ones that may,are ones that were replaced by a dealer under warranty,and even then it was rare,as I have never seen one.

[MadCityMike]

I pulled my harmonic balancer and crank gear and I do see a little bit of galling on the end of the crank nose, but the notch seems nice and square.  The key on the crank gear seems nice and square with no noticeable deformation at all.   I ordered the upgraded harmonic balancer and it should be here tomorrow.   Most places I called wanted around $400 US for it, but one place only wanted $130 which seemed awefully cheap so I asked him to double check the part # and he kinda gave me attitude and was sure it was correct, so I'm hoping it'll be the correct part.   Since it's all apart I'm thinking I should probably just go ahead and replace the crank gear as well.    Oh yea, I got a new bolt as well.
It's probably only been about 5000 miles since the timing belt was replaced and that was by a US garage.    Previous to that it was in Canada and I'm guessing those garages must have had a better idea of the problem and to torque the bolt down correctly.    I'm pretty sure this harmonic balancer is the original because it's actually got quite a bit of material worn away from the timing belt right up to where the crank gear sits.    

I'm afraid I might have moved either the cam or IP gear though so can someone highlight how each gear should be aligned assuming the motor's at TDC?   I've got a Bentley on order, but am really hoping to have this done within a day or so.

[ibmserf]

Question...is it the crank gear bolt that usually comes loose or the crank pulley bolts.  I believe that there is just one crank gear bolt and 4 crank pulley bolts...is this correct?