Cam sprocket question - timing belt change

Hi,

Has anyone ever change a timing belt without removing the cam sprocket?I've done it with my gas car...Slipped the belt on, put the tensioner on last. (factory manual said to remove it [cam sprocket] also)

I really don't like touching a bolt like that! *snap*

Tom

I've seen a couple of successful "Mark and Pray" jobs....but I can't recommend them. On an A4 when you adjust the tension on the belt....you leave the cam sprocket loose so it will turn on its taper(no key) and you leave the pump bolts loose so it's sprocket can rotate just a little.
Metalnerd makes a great puller for these.....and you counterhold as you loosen/tighten the 18mm bolt in the cam.

lrpavlo said:

I've seen a couple of successful "Mark and Pray" jobs....but I can't recommend them. On an A4 when you adjust the tension on the belt....you leave the cam sprocket loose so it will turn on its taper(no key) and you leave the pump bolts loose so it's sprocket can rotate just a little.
Metalnerd makes a great puller for these.....and you counterhold as you loosen/tighten the 18mm bolt in the cam.

Click to expand...

I'm actually looking at his tools. I was thinking about buying everything that keeps the cam, pump and crank lined up (plus the tensioner tool).

What exactly is mark and pray? Doesn't sound like the method i'm going for...

Tom

Mark & Pray is putting marks on the Cam,pump,and crank as well as the belt, then taking the belt off....transfer marks to new belt and put it back on with the marks lined up......Not recommended

Drivbiwire's write up does it the correct way. I think both DieselGeek and TDIparts sell metalnerds tool set...great investment IMHO but if this is your first TDI belt you might want to have a Guru watching over your shoulder.
Also, Don't forget vag com for setting timing afterward!

lrpavlo said:

Mark & Pray is putting marks on the Cam,pump,and crank as well as the belt, then taking the belt off....transfer marks to new belt and put it back on with the marks lined up......Not recommended

Drivbiwire's write up does it the correct way. I think both DieselGeek and TDIparts sell metalnerds tool set...great investment IMHO but if this is your first TDI belt you might want to have a Guru watching over your shoulder.
Also, Don't forget vag com for setting timing afterward!

Click to expand...

I've been reading Drivbiwire's instructions - that's gotta be the best write-up ever.

I'm just trying to figure out why you have to remove the cam sprocket. Is the belt really that tight to get on with the belt tensioner loose or off?

I have done hundreds of timing belts, and no problems with the bolt on the camshaft sprocket. Take the sprocket off as everyone has said and your timing belt replacement will be succesfull.

Yes, 60,000 mi, and 120,000 miles. I marked the sprockets against fixed objects, never loosened pump or cam. Used recommended belt, not newer thicker. Injection timing came in at the top of the gray, right where I would have put it. If that is right on, how far off could the cam (the next sprocket) be. 50.6 average mpg at 150,000 miles. I had bought all tools, but never used cam lock, as never took off cover. Tip: mark crank sprocket under car, as it can turn so it doesn't show in the window, then you don't know which way to turn to find it. As it is supposed to be at TDC, you could turn even past 90 degrees without hitting anything, but must put it back when hooking up belt.

professor said:

Yes, 60,000 mi, and 120,000 miles. I marked the sprockets against fixed objects, never loosened pump or cam. Used recommended belt, not newer thicker. Injection timing came in at the top of the gray, right where I would have put it. If that is right on, how far off could the cam (the next sprocket) be. 50.6 average mpg at 150,000 miles. I had bought all tools, but never used cam lock, as never took off cover. Tip: mark crank sprocket under car, as it can turn so it doesn't show in the window, then you don't know which way to turn to find it. As it is supposed to be at TDC, you could turn even past 90 degrees without hitting anything, but must put it back when hooking up belt.

Click to expand...

Many ways to change a timing belt...depends on how close you want to be.