timing belt instalation

KLXD · Dec 12, 2017

If you're looking at the instructions on this site the last step on adjusting is a little off but the only removal is the timing belt cover.

You loosen the three bolts and rotate the pump shaft CW to advance.

And don't rotate the engine using the cam or pump. Only rotate with a wrench on the crank.

iuvalclejan · Dec 12, 2017

Windex said:
The adjustment on the Injection pump is via three bolts which hold the Inj pump pulley to the hub.

By loosening the bolts, the pulley can rotate independently of the hub, and will affect injection timing. It's part of the belt replacement procedure as detailed in part II where the pump is "pinned" with the holding tool (6mm pin).

If you follow the procedure to the letter, the injection timing often lands right where it needs to be or pretty close. The tensioning of the belt, Which bolts are loose, and the correct order of installing / removing the holding tools is especially critical.

If you skip steps or don't follow the procedure / use the correct tools, all bets are off.

I understand, but if the injection pump is a bit off, it needs to be readjusted using a VCDS. THe question I asked (which has still not been answered) is whether this adjustment can be done easily without removing any other parts once things have been put back together. I.e. are those 3 bolts easily accessible while the car is running?

Vince Waldon · Dec 12, 2017

The three sprocket bolts are easily accessible from the top of the engine compartment, once the upper timing belt cover is removed (two spring clips).

To be clear, however, the adjustment is not made while the engine is running.

You remove the timing belt cover and then loosen the three bolts slightly, tweek the pump a tiny nudge with the center bolt, retighten the three bolts, then start the engine and check the timing.

The stop-adjust-start-recheck timing cycle is repeated until the timing dialed in. The various alignment jigs, if built properly, will get the timing close enough for the engine to start and run reasonably well... dialing it in assures max fuel economy and power.

Windex · Dec 12, 2017

As above, the three bolts are rotating at engine speed (technically 1/2 engine speed) while the engine is running. If you can figure out a way to adjust them while they are spinning around, my hat's off to you.

Of course all of this is in the procedure detailed above, which you said you have already read. :-/

iuvalclejan · Dec 12, 2017

Vince Waldon said:
The three sprocket bolts are easily accessible from the top of the engine compartment, once the upper timing belt cover is removed (two spring clips).

To be clear, however, the adjustment is not made while the engine is running.

You remove the timing belt cover and then loosen the three bolts slightly, tweek the pump a tiny nudge with the center bolt, retighten the three bolts, then start the engine and check the timing.

The stop-adjust-start-recheck timing cycle is repeated until the timing dialed in. The various alignment jigs, if built properly, will get the timing close enough for the engine to start and run reasonably well... dialing it in assures max fuel economy and power.

Thanks!
I'm going to talk to the in-town mechanic who thinks he can do it ofr $670, but I doubt he's going to do the fuel injector pump tweak. I wish there was some way to do this job without all the special tools. For example, couldn't the camshaft be pinned by wedging a crowbar somewhere once it gets to TDC? There usually are many ways to do a job, not just following directions, but in order to do it well, a high level understanding is necessary, before getting down to the details. If I had more time and it wasn't so cold, I'd probably try this without the extra tools.

Windex · Dec 12, 2017

The tools are cheap if you make them - and not all that hard to make.

The Pump pin - A drill bit suffices.

There is no lock needed for the crank - you just need to keep checking the bellhousing to make sure the flywheel mark stays at TDC.

The cam plate can be made out of some mild Iron angle or plate.

The Sprocket buster for the cam sprocket can be made with rebar, but you will need to heat and bend it. I made mine out of an old real-estate sign.

The only other tool absolutely required is the tensioner "two prong" wrench - I made mine by heating and bending an old pair of needlenose in a vise.

Total cost for my ALH timing set was about $30 in materials and an hour's labor.

jokila · Dec 12, 2017

iuvalclejan said:
Thanks!
I'm going to talk to the in-town mechanic who thinks he can do it ofr $670, but I doubt he's going to do the fuel injector pump tweak. I wish there was some way to do this job without all the special tools. For example, couldn't the camshaft be pinned by wedging a crowbar somewhere once it gets to TDC? There usually are many ways to do a job, not just following directions, but in order to do it well, a high level understanding is necessary, before getting down to the details. If I had more time and it wasn't so cold, I'd probably try this without the extra tools.

You can have a full toolbox with a crescent wrench, hammer, a few screwdrivers, and one of those universal sockets. That will save you a lot of money. Being cheap has consequences though.

The tools can be rented for about $50. Is that too much to spend?

Lightflyer1 · Dec 12, 2017

Use sticks and stones and puppy dog bones if you want to. They work in a pinch. You are definitely not cut out to own one of these cars. You need to sell this car and buy yourself a non interference engine car. There is no problem changing a timing belt on those and no special tools needed. You can also just change only the belt if you want to.

AndyBees · Dec 12, 2017

Uncle!

1854sailor · Dec 12, 2017

iuvalclejan said:
...For example, couldn't the camshaft be pinned by wedging a crowbar somewhere once it gets to TDC?...

PeterV · Dec 12, 2017

The show me state......

TDIs are NOT EASY. follow the rules or have a pro do it. Unless you have deep pockets.

Vince Waldon · Dec 12, 2017

iuvalclejan said:
For example, couldn't the camshaft be pinned by wedging a crowbar somewhere once it gets to TDC? There usually are many ways to do a job, not just following directions, but in order to do it well, a high level understanding is necessary, before getting down to the details.

Unfortunately this job is *all* about the details, because these are interference engines and because even small errors in the exact simultaneous alignment of three sprockets/shafts can have a significant effect on the engine's performance and/or economy.

And of course, if the alignment is off enough, the health of the engine itself is up for grabs if valves meet pistons.

It's really the only precision thing there is on this car... but there you have it...it is in fact precise.

For example, a crowbar as an cam alignment jig would not be precise enough because the jig is not just a lock.. it's a piece of metal milled to the exact right profile to ensure the cam is exactly at TDC. Technically speaking, even the correct jig is then shimmed with thin feeler gauges, to get it even more close to being perfect.

The jig is how we know the cam is exactly at TDC, as opposed to a lock for once the cam gets there.

A game of thousandths of an inch, so yup, all about the details.

Ol'Rattler · Dec 12, 2017

iuvalclejan said:
Does autozone or O'Reilly's lend a VCDS?

Additionally, do not put garbage Chinese parts on you Dub from AutoBone or O'Reilly's. In the long run, garbage parts end up costing more than buying quality parts the first time.

iuvalclejan · Dec 12, 2017

Vince Waldon said:
Unfortunately this job is *all* about the details, because these are interference engines and because even small errors in the exact simultaneous alignment of three sprockets/shafts can have a significant effect on the engine's performance and/or economy.

And of course, if the alignment is off enough, the health of the engine itself is up for grabs if valves meet pistons.

It's really the only precision thing there is on this car... but there you have it...it is in fact precise.

Precision does not equate to following the details in one way to do the job.

Vince Waldon said:
For example, a crowbar as an cam alignment jig would not be precise enough because the jig is not just a lock.. it's a piece of metal milled to the exact right profile to ensure the cam is exactly at TDC. Technically speaking, even the correct jig is then shimmed with thin feeler gauges, to get it even more close to being perfect.

The jig is how we know the cam is exactly at TDC, as opposed to a lock for once the cam gets there.

A game of thousandths of an inch, so yup, all about the details.

Why can't I pin all 3 shafts before I take the old belt off (the inector pump with a drill bit, the camshaft with a crowbar, don't even need to pin the crankshaft since it's got lots of mass and friction from pistons), then put the new belt on? Maybe the tensioning makes a difference, but I could count teeth on the belt between each two shafts to keep things the same. It doesn't even need to be at TDC this way (only relative position of the shafts matters), but it will be since the drill bit won't fit in the injector pump unless it's at TDC.

iuvalclejan · Dec 12, 2017

Windex said:
The tools are cheap if you make them - and not all that hard to make.

The Pump pin - A drill bit suffices.

There is no lock needed for the crank - you just need to keep checking the bellhousing to make sure the flywheel mark stays at TDC.

The cam plate can be made out of some mild Iron angle or plate.

The Sprocket buster for the cam sprocket can be made with rebar, but you will need to heat and bend it. I made mine out of an old real-estate sign.

The only other tool absolutely required is the tensioner "two prong" wrench - I made mine by heating and bending an old pair of needlenose in a vise.

Total cost for my ALH timing set was about $30 in materials and an hour's labor.

I am not really set up to fabricate tools right now, but thanks. Which tool is the one used to pin the cam? Is that what you call the cam plate?

iuvalclejan · Dec 12, 2017

jokila said:
You can have a full toolbox with a crescent wrench, hammer, a few screwdrivers, and one of those universal sockets. That will save you a lot of money. Being cheap has consequences though.
The tools can be rented for about $50. Is that too much to spend?

I'd rent the tools, but I don't think there is anyplace near me that rents them...Is there?

Ol'Rattler · Dec 12, 2017

iuvalclejan said:
Precision does not equate to following the details in one way to do the job.
Why can't I pin all 3 shafts before I take the old belt off (the inector pump with a drill bit, the camshaft with a crowbar, don't even need to pin the crankshaft since it's got lots of mass and friction from pistons), then put the new belt on? Maybe the tensioning makes a difference, but I could count teeth on the belt between each two shafts to keep things the same. It doesn't even need to be at TDC this way (only relative position of the shafts matters), but it will be since the drill bit won't fit in the injector pump unless it's at TDC.

Lightflyer1 · Dec 12, 2017

The places listed already will mail them out to you. If you would even do a minimal job of investigating what has been told to you here and the instructions given you would already be ready to do this job successfully. Trying to reuse parts and skimp on things and go your own way will only result in failure. You aren't the first person to come here and be instructed on how to do this. Many after trying things as you suggest. Either get with the program and do it right or quit wasting time. You are getting close to troll status with the stupid things you have suggested instead of following the procedure. A crowbar, right. Everyone uses that for doing their timing belt.

maxmoo · Dec 12, 2017

iuvalclejan said:
Precision does not equate to following the details in one way to do the job.

Why can't I pin all 3 shafts before I take the old belt off (the inector pump with a drill bit, the camshaft with a crowbar, don't even need to pin the crankshaft since it's got lots of mass and friction from pistons), then put the new belt on? Maybe the tensioning makes a difference, but I could count teeth on the belt between each two shafts to keep things the same. It doesn't even need to be at TDC this way (only relative position of the shafts matters), but it will be since the drill bit won't fit in the injector pump unless it's at TDC.

I see troubles and trials in your future.

n1das · Dec 12, 2017

iuvalclejan said:
Precision does not equate to following the details in one way to do the job.
Why can't I pin all 3 shafts before I take the old belt off (the inector pump with a drill bit, the camshaft with a crowbar, don't even need to pin the crankshaft since it's got lots of mass and friction from pistons), then put the new belt on? Maybe the tensioning makes a difference, but I could count teeth on the belt between each two shafts to keep things the same. It doesn't even need to be at TDC this way (only relative position of the shafts matters), but it will be since the drill bit won't fit in the injector pump unless it's at TDC.

If you try this, you will run into a problem when you tighten the tensioner to set tension on the new belt. The cam and injector pump sprockets will need to rotate backward slightly as you tighten tension on the belt. This is totally WRONG! You won't be able to compensate by counting teeth on sprockets. This where the old school "mark and pray" method that you want to use totally FAILS. The result is retarded cam and pump timing and maybe pistons kissing valves. The factory procedure in the how-to details the correct method to keep everything set correctly when tensioning the new belt.

Note there are 4 bolts in the passenger side engine mount which has to come out during a timing belt change. These bolts are torque to yield (TTY) bolts aka stretch bolts and can safely be used only ONCE. These bolts are taken out during a timing belt change and absolutely MUST BE REPLACED with NEW bolts. You take one of these bolts out for ANY reason, you MUST replace it with a new bolt. VW dealers are notorious for reusing instead of replacing these bolts and often don't keep replacements in stock. There have been a few cases of the bolts breaking and the engine falling to the ground after a timing belt change done by VW dealers. These bolts are marked "Always replace" in the Bentley manual.

The bolt for the large roller guiding the timing belt is also one of these bolts and MUST BE REPLACED with a NEW bolt when changing the large roller. All one-time use stretch bolts are marked "Always replace" in the Bentley manual.

Don't overlook the 3rd of 3 horizontal bolts in the engine mount bracket. This bolt is hidden and often missed when reinstalling the bracket. The bracket eventually breaks because the engine is held by only 2 bolts instead of 3. When the bracket breaks apart, it tears a hole in the block as the engine drops to the ground. The result is a destroyed engine because of the gaping hole in the block where the engine gets mounted.

The factory timing belt procedure described in the how-to absolutely MUST be followed TO THE LETTER in order to ensure a successful outcome. Following the factory procedure and using the correct tools will ensure that the cam, crank and pump are indexed EXACTLY like they were when the engine first left the FACTORY. The job is all about the details and following the correct procedure. This is not the time or place for old school shortcuts and not using the correct tools.

Since you are located in MS, I recommend getting the car to TDIclub GURU Oilhammer to do the job to guarantee the job is done correctly.

Good luck and Welcome to TDIclub.

jokila · Dec 12, 2017

iuvalclejan said:
Precision does not equate to following the details in one way to do the job.
Why can't I pin all 3 shafts before I take the old belt off (the inector pump with a drill bit, the camshaft with a crowbar, don't even need to pin the crankshaft since it's got lots of mass and friction from pistons), then put the new belt on? Maybe the tensioning makes a difference, but I could count teeth on the belt between each two shafts to keep things the same. It doesn't even need to be at TDC this way (only relative position of the shafts matters), but it will be since the drill bit won't fit in the injector pump unless it's at TDC.

Does the document you supposedly read say you can do that? Does it even come close to that? You have zero experience in doing the timing belt procedure and yet now you again are asking about completely deviating from the recommended steps and want some feedback as to why you can.

I think this guy is trolling the forum. "You can lead a horse to water, but you can't make it drink."

1854sailor · Dec 12, 2017

Good night...

KLXD · Dec 12, 2017

I'm beginning to think someone's pulling our collective chain. Three pages to come around to describing a M&P procedure.

iuvalclejan · Dec 13, 2017

Hey guys, sorry to ruffle your feathers. It looks like I previously missed some of the replies, not sure why. It's not that I'm not willing to follow detailed procedure, but the way my brain works, I also need to understand why I'm doing things, and I like to be able to think of new ways of doing things if needed. My short term memory is also starting to go, so it's hard for me to do things on the fly anymore, and so following procedure might be a good idea. Last time I changed the struts it started to rain before I could tighten the lug nuts back on one of the tires and I went inside thinking I would do it in the morning but I forgot...Found out later while I was driving...
I think I did a TB on a regular car many years ago and it was pretty easy. But it appears this one is not (as it warns in that how to link)
I guess I will talk with the Kirksville mechanic tomorrow and if I feel confident that he can do it (I'll tell him about the bolts that need replacing and the tweaking of the injector pump) I'll either rent the tools by mail (I missed that option before, I thought I have to rent them in person) or go down to Columbia (a 2 hour drive, hope the car makes it) to one of the trusted TDI mechanics.
I still don't understand why tensioning can cause loss of shaft alignment though, please bear with me. The way my brain works I don't just want to fix the problem, I also want to understand the problem. Isn't the camshaft sprocket keyed into the shaft so that there is only one orientation that works? Maybe there is enough play so it makes a difference? From the description of the tweaking of the injector pump shaft, it appears that its sprocket has some play, but for that shaft a drill bit will suffice. So what does the special camshaft keying tool do if not just lock the camshaft (which, ahem, don't mean to upset anyone, can be done with a crowbar)? It can't key in the sprocket, since its on the other end of the shaft?

iuvalclejan · Dec 13, 2017

Wait, I think I get it. The special camshaft tool keys in the shaft (not the sprocket) to just the right spot, within fractions of a degree. But then why do people say it's not necessary to have that tool if the valve cover can be removed and TDC can be visually inspected from the positions of the cams (and the crankshaft marks)? That visual inspection is not that accurate.

UhOh · Dec 13, 2017

iuvalclejan said:
Wait, I think I get it. The special camshaft tool keys in the shaft (not the sprocket) to just the right spot, within fractions of a degree. But then why do people say it's not necessary to have that tool if the valve cover can be removed and TDC can be visually inspected from the positions of the cams (and the crankshaft marks)? That visual inspection is not that accurate.

Visual (valve cover off) is only of value in determining whether you're on the right stroke. If the car was running AND when one pulls the TB AND doesn't rotate anything the CAM will be in the correct stroke. You're NOT 180 degrees out, but, THIS IS NOT CLOSE ENOUGH, which leads to...

The need for a cam indexing tool (some call it a "locking tool" - it is NOT a locking tool- don't rely on it to counter-hold against torque) to position the cam precisely. There are two types of these tools. BOTH insert into the end of the camshaft (with vacuum pump removed). But...

One cam indexing tool can be used w/o removal of the valve cover. If the engine was running fine before undertaking the TB job (and the valve cover doesn't need to be removed for inspection or sealing) then this type would be preferred. Valve covers like to leak; if you don't have to remove one then don't.

The other cam indexing tool is necessary when one is basically starting from scratch (new top-end parts, TB failure- timing messed up), where it is necessary to get a visual on the position of the cam (both lobes up for cylinder #1 = correct stroke).

IF you follow the procedures, and one should read, read, and then re-read them BEFORE engaging in this work, and then READ and follow in exact detail AS you do the work, you WILL have things lined up such that timing will be within spec (timing can then be finely set via VCDS). I had a friend assist me when I did my first TB: I had him audit every step (according to the document/procedures) as I did them; car started instantly and in over 45k miles I have not touched the timing (it was verified via VCDS to be set perfectly).

Pencil/pen and paper. That's what I use if I need to ensure that I finish something (if I'm concerned about forgetting- I have so much stuff going on that it is, for me, VERY easy to become distracted).

whitedog · Dec 13, 2017

The cam isn't keyed to the sprocket. It is locked in place with a taper fit. It is aligned by having the crank at TDC and the cam held accurately at TDC when tensioning the belt and before tightening the cam sprocket bolt. The injection pump gear moves as well when tensioning the belt and the bolts are loosened just enough to allow the pump sprocket to turn.

If whoever does this job doesn't understand this, then call the engineer because the failtrain is ready to leave the station.

Windex · Dec 13, 2017

Dude.

For the Nth time, read the procedure. It's all there.

The cam (as above, and in the procedure) is not locked to the cam sprocket.

If you do even a little research, you will find that the tools are not that hard to make, or that there are several people willing to rent them.

From the procedure:

From Part II

The sprocket is pressed on by a tapered fit. It might look like there's a key missing but there is not supposed to be any key on the camshaft sprocket. This is a major reason why you must use the timing belt tools to lock the camshaft position.

From part III:

Slip the belt over the camshaft sprocket and then slide the camshaft sprocket onto the taper. Put the 19mm camshaft sprocket bolt on but leave it about 1/2 cm off. This will let the camshaft sprocket rotate when you tension the belt. This can also catch the sprocket if it falls off. Again, the camshaft lock bar holds the camshaft in place while the camshaft sprocket can rotate independently - this is why you need to use the camshaft lock bar and need to loosen the sprocket! There is no missing key on the camshaft, the sprocket is a tapered/conical fit to the camshaft end. It's also difficult to put the new belt on unless the camshaft sprocket is off.

... But then you already read those thoroughly...

iuvalclejan · Dec 13, 2017

Windex said:
Dude.

For the Nth time, read the procedure. It's all there.

The cam (as above, and in the procedure) is not locked to the cam sprocket.

If you do even a little research, you will find that the tools are not that hard to make, or that there are several people willing to rent them.

From the procedure:

From Part II

From part III:

... But then you already read those thoroughly...

I read that from part 2 and promptly forgot it since like I said, details don't mean much until I get the big picture. As far as part 3, you're right, I haven't read it yet since it costs money. I will only read it if I end up doing the job.

But if it's not keyed in, then why does part 2 say to remove it )or just to loosen it, can't remember) at one point? That makes no sense to me. How do you then get it back into just the right position? Maybe it doesn't matter as long as the shaft stays put. I have to think about that.

AndyBees · Dec 13, 2017

When the Cam Sprocket is actually totally removed (at least that's how I do it) and the Injection Pump Sprocket loosened (three bolts in slots), the TB is easily slipped on. A new TB is as stiff as a dead alligator's tail.

With those two sprockets loosened is the correct method of installing the TB. The Lock Plate inserted on the opposite end of the Cam keeps it in Time. The Pin in the IP hole/slot keeps it in Time. The Crankshaft holding device keeps the flywheel TDC mark at the pointer as observed through the hole in the bell housing. The crankshaft holding device is not strong..... just a very simple holding device to keep you in the ballpark.

With everything in place, 19mm Cam bolt only finger tight (maybe just a little more) and IP Sprocket bolts finger tight, tensioning of the TB is easy. Then, tighten and Torque the 19mm bolt to 40lbs (book says 33, do 40). Then, with a 22mm wrench on the big nut on the IP, you rotate the shaft (very slightly) to center the three bolts in their respective slot, then tighten (do not torque to spec at this point). Now, the timing will be almost 100% near perfect and the engine will start assuming all else is fine. (Do not loosen the big 22mm nut on the IP.)

Once the timing is checked and/or tweaked with VCDS, the three bolts should be torqued per spec.

You need the services of a guru ....... any other establishment will most likely have a bad ending.

timing belt instalation

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