3B timing belt question...

**denniselbows** · 2 March 2011, 21:04

How much slack on the left hand side do you have? 5mm movement or more ?. Have you checked the lines in the dizzy are lined up. There also a very small chance the key in the cam pulley is starting to shear. The first time I did my cam belt I replaced the seal behind the cam pulley and held the Lilly to undo the bolt all was fine untill I did it up again sheared the key right off. Only found out when I went to time it up as it was all to **** . Took me a good couple hours to work it out.

**kingfishers2** · 2 March 2011, 21:24

I had this on a 7a recently turned out the tdc mark on the bottom pulley was out, check the mark on the flywheel in the transmission window is lined up correctly this might sort it.

**rs200** · 2 March 2011, 22:07

bottom timing belt pulley are brand new , upper pulley are good too.. water pump are new , and roller pulley for timing belt (74mm) , are allso new..
everithing is OEM.. acept timing belt .
the mark on flywheel are good too , everithing is ok and perfect.. acept that timing and timing belt left side tension of the belt..

i don't know how much movement they have... few milimeters .. and they are not straight like on right side.. on friends AAN I make tension on each side without any problem... than I start to thing about my 3B which don't have adjustable roller pulley on left side of the engine..

the problem is (I don't fell it when I drive the car but) that engine make tense the belt in one side - on right side - you drive the car and you relise gas pedal and engine make the tension in other direction , because crank are heavier than cams are.. and then they tense the timing belt in left side , and than you pres the gas again , than engine tense timing belt in right side..
and here is the problem that timing belt don't have good tension on each side , and that is not good for engine or for timing belt..
on AAN ,ABY ,ADU , they fix that problem , and they are much better than 3b..

what to do.. I have to change engine block, or drill 3 wholes in block for 3 bolt which hold the timing belt tensioner , change the oil pump , timing belt .. it is a big piece of work.. only to tense the left side of timing belt..

**denniselbows** · 2 March 2011, 22:09

You know when I looked at the photo I thought there was a red line pointing to the flywheel indecating he was using the flywheel mark to Time up the engine but when I looked again it was the dip stick . What a pilock

if you are using the Mark on the front pully they do tend to be out and makes timing hard work .

**newsh** · 2 March 2011, 22:59

I think you are overthinking this. The belt has to pull harder to turn the cams when opening valves than when closing them, so at certain crank positions it will seem tighter on one side than the other, but its a continuous belt so really the tension is always on the side that pulls the cams, if you turned the engine backwards it would be tighter on the other side.. but just taking your foot off the gas will not do that.

Hmm, now I'm overthinking it too!

**rs200** · 2 March 2011, 23:23

I undertand what you want to say.. and that is true.. most important is that must be in at goo timing when crank pulls the cams. that is ok. but when you pull off the gas pedal , than tension go on other side. and that is a part which make me headache.

they must have tension all around the timing belt..newsh .. you have 3b engine too , if I remember well .. so how is the left side of timing belt on your car?

**newsh** · 3 March 2011, 08:39

Well the tension should be the same on both sides unless the valve gear is trying to slow it down or hurry it up, so to speak, I will try to have a look later as the front is off my car

**newsh** · 3 March 2011, 10:18

Just had a look at mine. It's the same as yours, feels tight on the right and a little slack on the left.

**simon20vq** · 3 March 2011, 11:18

I have 3B I'm in the process of replacing/cleaning/moding things and yesterday I was checking the cambelt. The right side of belt is spot on left very slack BUT As NEWSH said this is no real problem UNLESS something else is amiss. Although I have seen this on other cars I've owned. Out of interest how did you remove the bottom pully? (Crank pully)

**simon20vq** · 3 March 2011, 11:25

Funny just seen the link in KIERON20V who is selling Audi locking tool 2084. BUT how else can you lock the crank without putting pressure on cambelt of cam pully?

**rs200** · 3 March 2011, 11:43

how did I take of crank pulley.. well.. first slam few times on pulley bolt with hammer ,than put car in 4. gear.. somebody must hold the brake , than you can unlock the bolt on pulley , but use log metal pipe on your tool..

**newsh** · 3 March 2011, 15:42

Noooo!

Use a crank locking tool, fits inside the front pulley.

**rs200** · 3 March 2011, 16:27

Originally posted by newsh

Noooo!

Use a crank locking tool, fits inside the front pulley.

this solution is 100000 time better , but if is emergency to unlock the pulley.. than my solution could help..

**newsh** · 3 March 2011, 22:57

Yes, you can actually bend the crank and/or overstress the gearbox doing it that way, 550ft/lbs at 0 RPM, think about it..

Also you're holding the wrong thing still if you hold the crank, you need to hold the pulley so the key doesn't shear off the timing wheel.

3B timing belt question...

3B timing belt question...

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