Hi all,
as previously mentioned, i have a Mk3 Golf with engine code AAM. I'm just looking through the Haynes manual as the timing belt needs replacing and I'm assessing my ability to do it!
On my engine the belt loops round the crankshaft,camshaft,passes the circular tensioner and also drives the auxilliary shaft. I think the auxilliary shaft drives the distributor so its timing is important.
Off the cranksaft are some vee belts which drive the power steering pump,alternator and water pump. The water pump is not driven off the timing belt.
Do i need to remove the crankshaft pullys in order to remove the lower timing belt covers to get at the belt?
Do i need any special service tools? eg the tensioner has two holes for a "special" adjustment tool.
Are the timing marks on the craknshaft end,cam sprocket and aux shaft obvious?
Thanks
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As it happens, I changed one of these last week. All crank vee pulleys need to come off - but the same 4 bolts hold them all on. Very annoyingly, the water pump pulley has to come off too - stupid detail. I used an oil filter strap wrench to hold it whilst the retaining bolts were removed.
The "special adjustment tool" for the tensioner can be a pair of right angle circlip pliers. The applied torque to get the required belt tension is quite small.
The timing marks are reasonably obvious - I used the flywheel marker to maintain TDC. The camshaft is clearly marked but the auxiliary shaft marker is just silly - but as there is no locked-in torque on this shaft, the job is straightforward if you are careful.
Other than the water pump detail, this job is dead easy. Watch out for corroded fixings - when will VAG use proper plating on these parts?
659.
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Just to add to that. On the ABS '94 engine - so I assume its similar - you need to align the crank pulley with the mark on the lower cover - a bit annoying as you have to put it on / off / on / off whilst you get it correct & check it. Once the cam & crank are done, then put the intermediate shaft into position. Dead-easy just take the dizzy cap off and line it up with the mark. The crank pully is keyed - so make sure its in the correct place.
Haynes and AutoData seem to miss (unless I've misread) doing the crank alignment first....
The belt tension on the crank - intermediate shaft should be 90' twist in the middle. re-check it again when you've done it and the car is hot, to make sure its not overtight.
Let us know how you get on.
James
PS - new bolts are £2 from VW. Worth it if the heads are stripping!
Edited by Javalin on 19/02/2009 at 21:11
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It was because of VAG's absolute idiocy in putting the crank timing mark on the cover (which of course you've just removed to fit the belt) that I used the mark on the flywheel.
Just to add to my post above, one thing you can't do without is a good 6mm AF hex key - the type which fits into a socket. The V belt pulley bolts are tight and soft, using anything other than this tool to shift them will end in grief. Get an assistant to hold the flywheel with a big screwdriver on the ring gear teeth (access hole in bell housing) whilst you remove and replace these bolts.
All cambelts tighten as the engine heats up and expands. The 90 deg twist test is "valid" for a cold engine - don't loosen the belt.
Other than the odd wrinkle, this is a very easy belt to change.
659.
Edited by 659FBE on 19/02/2009 at 22:29
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Agree, this is a fairly easy belt to do, but last poster is right, get the right size tools.
You can try taking off the water pump (with hoses attached) as this will give you enough room to slip the cam belt round. Probably less grief than trying to remove the pulley. You will lose all the coolant so do it cold. Nice if you are due a coolant change too.
There is a mark on the crank pulley, which is aligned with a mark on the intermediate shaft, while making sure the mark on the cam wheel is aligned with the top of the head.
I personally do not try and hold the ring gear with a screwdriver. But if plugs are removed, bring up No1 cyinder by turning the crank with a 19mm socket, and just after it starts to come up stuff down a long piece of soft rope into No1 cylinder through the plug hole, and then wind the crank up again. This will jam the engine solid. Got me out of trouble lots of time when an engine has to be locked. Wind it backwards to remove the rope. It has been argued that the rope can be chewed up (not found it in 30 years) but if it did I would be confident the bits would burn off harmlessly.
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Hello 659
How do you get to the flywheel on this engine? Isn't it rather hidden by the gearbox?
That said - there is a green plug in about the correct position on the gearbox/block - but I think thats just a lube hole?
On the same subject - are there spark timing marks anywhere on this engine? I.e. for setting the dizzy advance etc? I've seen some are marked - so you can use a timing light....?
J
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The green plus IS NOT A LUBE HOLE. Dont put oil down it. By pulling out the green plug you can see the TDC and timing marks. The timing mark is really for static timing. This engine has to be at temperature and high revs to set the timing properly. Once these engines are set there should never be a reason to change the timing. Get a manual and read it carefully. Alignment of all the shafts is quite easy and marked. If the covers are off it does not matter as you align the shafts with their own marks to each other, and the cam drive to the head.
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oh ok. Seem them in Bentleys (manuals not cars') - will have to check out of interest now.
Cheers,
James
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The tensioner wheel I took off (at about 80k miles) was a really shoddy plastic wheel made by FAG. The date code on the plastic moulding signified that it was the original. The bearing was dry and loose. The replacement which was made by INA was all metal, suitable for the job - available as part of a timing belt kit from GSF.
The kit also includes a new stud, nut and spring washer for the tensioner. I fitted them, but I can't see how an M10 stud can possibly fail in this location - the old one looked fine.
Don't take any chances with the FAG tensioner. This is another case where pattern parts are better than OE.
659.
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Hi again,Im the OP...
OK i did some exploratory surgery today and there are a couple of bits that are unclear.
Engine code AAM the crankshaft end has two vee pulleys,one to drive the PS and the other to drive the alternator and water pump. This engine has had a timing belt done before. The four hex bolts came off easily from the vee pully (crankshaft) but there is also a centre bolt which isnt hex head but more a male splined head. Does this have to come off too ?
I only ask as after removing the four hex bolts,nothing really seemed to be loose!
Also i note that the water pump pully might partially block removal of the plastic lower cover. Is it possible to sneak the cover past the pully or do i REALLY have to remove the water pump or its pully?
There are already some white paint dabs on the cam sprocket so I'll guess there are some on the intermediate shaft and c/s pullys.
The existing tensioner is the metal one..
Just noticed a hole in my sill..more woes...maybe i shall just trade the car in/sell/get a newer one??
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Don't remove the centre crankshaft bolt. The vee pulleys are on a register and will come off with a bit of wiggling. It's worth noting which way these pulleys fit - there's a slot in the bore to mark the position of the first one.
The water pump pulley does have to come off - it's just too big to allow you to shift the cover. I would definitely not remove the pump itself unless you want water leaks.
If you can find the flywheel TDC mark under the plug in the bell housing, there's no possibility of getting the position wrong. Likewise, the camshaft is really well marked. The auxiliary shaft isn't - the mark is on the pulley you removed. As an insurance, I removed the distributor cap and marked the position of the rotor relative to the distributor body. It was very near the scribed mark used by Bosch to denote No 1 TDC.
If you can shift all the rusty unplated bolts, this job is easy. Don't lose the stud when you come to refit the lower timing cover...
659.
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Dohhhh.hex screws on water pump pully will not move. Applied as much force as i dare with the drive belt still on and car in gear. No joy. Considered applying some heat but didnt due to tight area. Dont really fancy pulling off water pump. Stupid VW. Why dont they design an easy to maintain car?
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Which is why I suggested taking the water pump off. Only 3 bolts and an O ring seal (£0.8p) from GSF or even VW.
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I'm afraid it's silly details like this which are partly responsible for VAG's relatively poor reliability. The average mechanic, faced with a problem like this is likely to do something detrimental to the vehicle. Other routine servicing jobs (eg fuel filter on '05 4 cyl diesel Passat) are just as needlessly bad. The Japanese don't do this.
I found it essential to restrain the water pump pulley with the strap wrench in order to have any hope of shifting the 4 pulley bolts - the belt is nothing like tight enough. These bolts are the same as those on the crank vee pulleys, so in theory they should be no harder to shift. Once the pulley was adequately held - its flat profile helps - the bolts were not too difficult to shift.
659.
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Have considered further..i have in my tool kit a good sized chain wrech. I can hold the pully with the chain wrench and try the hex wrench again. Failing that,tap the hex wrench firmly into bolt head and use gland nut pliers to grip the hex bolt externally. My reasoning is that I'll be applying the force on the external perimeter of the bolt,thus applying more force thean can be applied using the hex key. Also the hex key can only take so much force before it may slip,snap or slip ! What a crzy idea to put hext bolts on here. With decent bolts i could have used a socket,
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Yes, bolts with internal provision for the operating key (internal hex, torx etc) are stupid for high torque applications - see my earlier post on VAG detailing. I would not use a chain wrench on the water pump pulley as any surface damage here will seriously shorten the life of its driving belt. I used a fabric oil filter strap wrench.
Use a good quality 1/2" drive 6mm AF hex key, tap it firmly into the bolt and crack it loose with the pulley firmly held. If I remember correctly, you can get to the back of these bolts to apply a little penetrating oil.
659.
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A fibre strap wrench is a good idea but where the strap winds up to tighten you can damage the pulley so a little care. The other option is to cut the belt, it news a new one anyway, and cut a length that is just short of the circumference then use the chain wrench on top of the belt, fully protected and max adhesion to the pulley. Regards Peter
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Well the job is finally done.
I got two hex bolts out of the water pump pully fairly easily but the last one was a pain. The old belt and tensioner had done about 50,000 miles and visually,looked ok. The tensioner spun freely but did have a slightly edgy feel to the bearing.
Fortunately the VW Main dealer who changed the belt first time round,helpfully painted some blobs on the teeth of the crank,cam sprocket and aux shaft so when i put the engine in tdc using the manufacturers mark on the cam sprocket,all the paint blobs lined up nicely !
Top tips for other amateur mechanics like me doing the same job,,
Make sure you have a 3/8 or 1/2 drive hex socket to fit the daft hex bolts and that it is good quality and an accurate fit.
Clean out the heads of all hex bolts before putting that socket anywhere near them.
If your engine isnt already marked up, set the engine in tdc and accurately paint blob all the cogs so that its easier to reset when you fit the new belt.
Belt tension should be max 90 degree twist mid way between the cam sprocket and aux shaft.
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