Timing belt change questions - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

Timing belt change questions by rackley on 20 Feb, 2005 21:28
First and foremost, what size socket is that 12-pt crank bolt?

Can the spanner wrench for the tensioner adjustment be picked up at any local pep boys/autozone/etc or is it a special order part? If it is, can I 'get away with' using something else?

Thanks,
Ray
#1 by Northboundtrain on 21 Feb, 2005 06:11
The only specialty tools you need to have are the camshaft locking plate, injection pump locking pin, and the timing belt tensioning tool. The waterpump pulley wrench would be very helpful too. Don't try to replace your timing belt without these tools; you can't do it right and it's not worth wasting your time. Call the PartsPlace 248-373-2300.
#2 by rackley on 21 Feb, 2005 20:38
For future searchers, I wound up getting a whole 12-pt socket set and the crank bolt is 19mm.

Also, I picked up all the tools from http://www.germanautoparts.com. All the VW tools are literally half or less of the dealer price and/or the price Parts Place wanted. http://www.germanautoparts.com/tools/Volkswagen

Ray
#3 by chrissev on 21 Feb, 2005 20:44
Quote from: "rackley"
First and foremost, what size socket is that 12-pt crank bolt?

Can the spanner wrench for the tensioner adjustment be picked up at any local pep boys/autozone/etc or is it a special order part? If it is, can I 'get away with' using something else?

Thanks,
Ray

Umm, last time I had a socket on the 12 point crank bolt I used an imperial size, I think it was either 9/16 or one higher, can't remember. It is just a regular 12 point socket. You can get them at any hardware store.

The wrench for tensioner adjustment can be substituted with a pair of bent end needle nose pliers. That's how I do mine. You also need a torque wrench as the correct torque is very important for the tensioner. Too tight or too loose can result in tragedy.

You'll also need the locking tool for the cam. You can substitute a piece of metal of the right size, or multiple pieces. The cam must be locked for the timing belt change because you need to loosen the cam pulley and if the cam turns when the pulley is loose then the timing will be quite a bit off.

You also need the locking pin for the injection pump. I have been told that a socket of the right size, or a bolt can be used for this. Not sure what size, cause I've never done it that way, but someone on here should know.

Other than that it is a very straightforward job and shouldn't take you too long. Only hard part is putting the belt on the crankshaft pulley and the injector pump pulley without having the crankshaft pulley turn.

Remember, THE CRANKSHAFT CANNOT BE ALLOWED TO TURN AT ALL, FOR ANY DISTANCE, FOR AS LONG AS THE TIMING BELT IS OFF THE ENGINE. Failure to follow this rule will result in valve damage and you'll need to rebuild your head.
#4 by janb on 21 Feb, 2005 23:02
Quote from: "Northboundtrain"
.... Don't try to replace your timing belt without these tools; you can't do it right and it's not worth wasting your time. ....

Yikes :shock: my fleet of 21 VW-d's is suffering under a derelict, but I will admit I waste a lot of my time on this iron. I just feel really bad :oops: for all the belts I've changed for friends, and even on my TDI :lol:

It must be a symptom of growing up in the seat of a tractor, suck'n diesel smoke for 12 hrs / day, We would have been in a real fix if we had to drive from Nunn, CO to Boulder to get the right wrench each time :roll:

fyi, a 3/4" wrench is 19.05 mm

Ray, don't know where you are at, but you found a good site (adirondack i.e. germanautoparts) You might want to verify your part prices here Halsey Import Parts (Portland, OR) 1.800-792-0081, they are tough to beat on most parts, but their price varies, because they buy bulk from distributors. Always specify German or Brazil, (if you care) where-ever you get your VW parts. Most quality places carry both. Unfortunatley I ran out of the $7.95 T-blts and $10 water Pumps I bought from RMAW, before they went belly-up (I had bought 10 each, but they only lasted a few months) My friend has over 75 VW-d's. so we do several engines / swaps / repairs / month.... so... let me know if you have any spare parts, we're always shopping.
#5 by dieselweasel on 22 Feb, 2005 02:24
Is it really necessary to use the cam locking tool? Won't a wrench or screwdriver of the right thickness work? Also is it really necessary to loosen the cam sprocket?
#6 by QuickTD on 22 Feb, 2005 06:38
Quote
Is it really necessary to use the cam locking tool? Won't a wrench or screwdriver of the right thickness work? Also is it really necessary to loosen the cam sprocket?

It is necessary to use something to lock the cam. I've heard of people using everything from files to stanley door hinges with success. Use your imagination.

I would definately loosen the cam sprocket. There can be enough manufacturing variation in belt pitch/length to throw the cam timing out enough to bend a valve. The pistons only miss the valves by .020" in a diesel. The only way to really get it right is to loosen the cam sprocket. It also makes the job of installing the belt much, much easier.
#7 by chrissev on 22 Feb, 2005 08:06
Quote
fyi, a 3/4" wrench is 19.05 mm

That's what I use. Thanks, forgot the size. It works great, because usually the bolt has some rust on it so is a bit bigger than 19mm.
#8 by chrissev on 22 Feb, 2005 08:10
Quote from: "QuickTD"
Quote
Is it really necessary to use the cam locking tool? Won't a wrench or screwdriver of the right thickness work? Also is it really necessary to loosen the cam sprocket?

It is necessary to use something to lock the cam. I've heard of people using everything from files to stanley door hinges with success. Use your imagination.

I would definately loosen the cam sprocket. There can be enough manufacturing variation in belt pitch/length to throw the cam timing out enough to bend a valve. The pistons only miss the valves by .020" in a diesel. The only way to really get it right is to loosen the cam sprocket. It also makes the job of installing the belt much, much easier.

Have you actually done this on an A2 diesel VW? The problem I have is that the injection pump locking tool doesn't lock the pump sprocket completely and it moves a bit, as does the crankshaft pulley. So if I loosen the cam pulley, all three things are moving and it makes it really difficult to get the belt on. I usually loosen the cam bolt but don't knock the cam pulley off of the taper lock fitting until after I get the belt on, then I knock it off and let it settle if it needs to. That way I can control movement of all three pulleys because the belt is already on.
#9 by QuickTD on 22 Feb, 2005 15:37
I've done lots of A3 1.9td's, only difference with them is that the automatic tensioner has less adjustment range and must be bolted into position (but not tensioned) before the belt is installed. I usually remove the cam sprocket, lock the cam and pump and then thread the belt over the crank, intemediate shaft, injection pump and the tensioner. I then insert the cam sprocket into the loop and then pull it up and onto the taper, always goes very easy for me.
#10 by chrissev on 23 Feb, 2005 08:21
Quote from: "QuickTD"
I've done lots of A3 1.9td's, only difference with them is that the automatic tensioner has less adjustment range and must be bolted into position (but not tensioned) before the belt is installed. I usually remove the cam sprocket, lock the cam and pump and then thread the belt over the crank, intemediate shaft, injection pump and the tensioner. I then insert the cam sprocket into the loop and then pull it up and onto the taper, always goes very easy for me.

well with the A2s they hadn't quite gotten the geometry of the pump gear/pump locking tool totally figured out (though it is better than the set up on the original diesel rabbits where the pump locking tool allowed for so much movement that it was almost useless). The locking tool still allows for enough movement that the pump gear can move half a tooth off center, making it very difficult to get the belt on right if everything is moving. That's why I leave the cam gear on until after I put the belt on.