Topic: A4 Timing Belt Change procedure
Drivbiwire
Finally the procedure we have all been waiting for the "A4 Timing Belt Procedure" including the Automatic and Manual transmission differences. Some people have argued till they are blue in the face that "mark and pray" was the easiest way to change one of these belt, and it has been proven that this belt can be changed in under 2 hours using the full factory method as demonstrated here in this thread. The procedure utilizes all the factory tools and processes. The reason for going to the extreme of utilizing all the tools is the elimination of all possibilities of making a $2500.00 mistake and destroying the head.

You do not need many tools to complete this job. What you do need is a thorough understanding of the procedure and what you are about to accomplish. When changing a timing belt you are doing more than just replacing an old belt. What you are doing whether performing a 40K on the auto or 60K on a manual is inspecting the entire engine area that has been covered up since the engine was new or since the last belt change.

The second most important thing this procedure accomplishes is it totally resets ALL timing setting on the engine and restores them back to Factory new settings. While on the topic of timing we need to understand that there are three types of timing involved here. The first and most overlooked type of timing is the cam and crank timing. This keeps the cam spinning in perfect time allowing the engine to produce great low end power as well as allowing the engine to rev to it's full redline of 5100 rpm.

The second type of timing is "Basic" injection timing. I concocted the word "Basic" timing because it is used to initially set and assure that the engine will start. This is accomplished by inserting the injection pump lock pin positioning the pump shaft in relation to cam and crank timing in such a way that injection will occur within the ignition window.

Once the cam & crank timing have been set and the Injection pump is positioned you will need to adjust the injection timing utilizing the Vag-Com http://www.ross-tech.com/ If you do not have this then get it before attempting to perform this procedure.


This leads me to my next point, tools. Everybody wants to know where to get them and how much they cost. The simple fact is they are not cheap, but neither is your engine... I use the factory tools that I got from http://www.zelenda.com/ . They sell all the tools you need for the job and they are the same tools the factory used to assemble your beloved engine so again it's your engine and your money.

The VW Factory tools you are going to need are:
-3036 Camshaft holding bar
-3418 Camshaft setting bar
-2587 2 pin spanner wrench (don't use a bicycle wrench this one costs the same!)
-3359 Injection pump lock pin
-T40001 puller set

Specialty tools your going to need from Sears:
-41831f Serpentine belt tensioner tool
-44360 11mm&10mm 45 degree offset wrench
-5mm 3/8 drive allen socket
-6mm 3/8 drive allen socket
-T25 Torx bit(1/4" drive)

Specialty tools from AutoZone:
Flat Band clamp tool

Other tools and "stuff"
(1) Block of wood, a 2x4 6" long will work great
(2) Jack stands (strong enough to support your car!)
(1) Hydraulic floor jack

Tools you have to make:
stubby 5mm 1/4" drive socket


Not to mention a set of metric 1/4, 3/8 and 1/2" drive sockets and extensions.


Now the fun part! I have to add If I have to explain how to remove the belly pan and the engine cover you may want reconsider performing this job and take it too your local dealer...no joke.



This engine represents a majority of the forum members in that it has an oil bypass filtration system, bypassed CCV system (Thank God no oil to drip on me !) and he is a proud member of Epsilon!




Using the "Flat Band Clamps" remove the intake tube going into the EGR/intake manifold








Remove the coolant reservoir connector, hose clamp and two philps screws.



using a 5mm 3/8 drive allen socket and extension, remove the allen bolt securing the power steering reservoir to the engine mount



Remove the two fuel lines coming off of the fuel filter, cap them off and insert them through the oil dip stick


Stuff some paper towels into the intake to prevent "Murphy's Law" from kicking in and prevent you from dropping that flying spring clamp into an intake duct!!

Raise up the power steering reservoir and pull the coolant reservoir hose under and to the front of the car. let the coolant reservoir hang on the front of the car.


Remove the timing belt cover, and the flex line coming from the air filter going to the engine, I strongly suggest stuffing some paper towel in both holes to prevent you from dropping something into the turbo inlet.






Using a 5mm 3/8 drive allen socket, remove all the front and driver side rear allen bolts except for the two by the oil filler cap. For those use the special cut-off 1/4" drive socket that you made to remove them. Believe me when I say this, I have tried EVERY possible way to do this and I have stripped out a few heads in the process and this by far is the only true easy way to do it.



Lets look at the head and gauge what we are going to do. On the right side of the camshaft is the vacuum pump, there is a slight difference in removal procedure between the auto and manual (not a big deal by the way). Anyway on the left side of the cam look at the first two lobes. These two lobes MUST ALWAYS be returned to the "both up" position, why you ask? If you don't its not a matter of if but you WILL wet the cam timing 180 degrees out of time don't ask how I can only say from my experience and that of others that it can and does happen. By the way this is a great example of a SUPER clean engine using Delvac 1 5w40 full synthetic, the best oil out there that meets the VW TSB oil viscosity specifications....had to through that in there


Remove the vacuum line running under the vacuum pump. MANUAL TRANSMISSION OWNERS, REMOVE THE CENTER GLOW PLUG WIRE AT THIS POINT AS WELL



Using a 1/4" drive deep socket remove the lower 10mm nut. MANUAL TRANSMISSION OWNERS, USE THE 45 DEGREE OFFSET 10MM WRENCH AND REMOVE THIS NUT. THE NUT WILL BE BETWEEN THE COOLANT HEATER HOUSING AND THE VACUME PUMP AND THIS WRENCH IS THE ONLY WAY TO GET IT OUT WITHOUT REMOVING THE COOLANT HEATER HOUSING.



Using the 10mm deep, remove the aft 10mm nut, this is the same for the manual owners as well, then remove the vacuum line support bracket.


Using a 13mm deep socket, remove the front vacuum pump bolt There are three of these 1 normal bolt and the other two have a threaded bolt on the top for the vacuum line support bracket


Remove the rear vacuum pump bolt


Remove the lower 13mm bolt. MANUAL TRANSMISSION OWNERS, USE A 13MM BOX WRENCH TO GET IN AND REMOVE THIS BOLT. THE COOLANT HEATER HOUSING WILL PREVENT YOU FROM USING THE DEEP SOCKET (BUT I SUPPOSE YOU HAVE NOTICED THAT...)


Remove the vacuum pump and bend it out of the way, you won't damage the line by bending it just make sure it does not fall damage could result.


Here is a picture of the end of the camshaft. The groove in the end of the cam is where the 3418 Cam setting bar is inserted. In a later step the groove as you would suspect will need to be rotated, the 3036 Cam Holding bar will be used to turn the engine into the correct position.


Using your two jack stands and a hydraulic jack, lift the car and support it at a height that is comfortable for you to get under the car. Now crawl under and remove the engines belly pan



Crawl under the car and at the back of the engine above the passenger side drive shaft is the turbo compressor outlet pipe. Using your "Flat Band Clamps" remove the spring on turbos Compressor outlet and pull the hose off of the outlet.




Use a 10mm socket and remove the nut on the turbo to intercooler pipe, then use the clamps and remove the clamp on the intercooler and remove the whole duct assembly.



[b]Remove the washer nuts using a long screwdriver by un-screwing them, or you can just pull off with some force but you may damage the washer so try this as a last resort. Then remove the side lower panel.



Using the Craftsmen 41831f Serpentine belt tensioner tool and the special short 16mm socket that came with the tool. (FYI a standard socket WILL NOT fit in this small space) Relieve the tension on the serpentine belt tensioner and remove the belt.




Using the 3036 Cam holding bar, rotate the engine until the cam lobes on the #1 cylinder (passenger side in "Normal world") are in the "Lobes up position and the groove in the cam pulley is level with the machine finished valve cover deck.


Install the 3418 Cam setting tool into the groove, you may need to work the cam back and forth a bit with the 3036 tool. The 3418 has a nit of flex to it so it hold the bar nice and tight in the groove preventing the cam from moving. In the A3's you needed to use feeler gauges but in the design of this tool they built in tension that eliminates the need to use feeler gauges as depicted in the Bentley Manual. THIS IS A GOT-YA, MAKE SURE THE #1 LOBES ARE IN THE LOBES UP POSITION BECAUSE OF THE FLEX IN THE 3418 TOOL IT IS POSSIBLE TO FORCE IT INTO THE GROOVE ON THE CAMSHAFT EVEN THOUGH ITS 180 DEGREES OUT, TRUST ME ON THIS ONE hehehe



NOTE TO AUTOMATIC OWNERSThis is where the Bentley fails at depicting what you are looking for. On the flywheel you are looking for a stamped circle with a "minus" sign on either side. The first link shows the timing mark when the cam setting bar was first installed. It should look like the second link with the circle and dashes at the very bottom of the window. At this point do not worry about the crank timing it is however "VERY" important for you to know what it looks like because of all the marks that can be construed as a "TDC" mark.



NOTE FOR MANUAL TRANSMISSION OWNERS this is a picture of the timing mark and the hole to observe it through. The hole is located at the very top of the transmission bellhousing (12 O'clock postion).




Moving back over to the Pendulum Engine mount by the Power steering reservoir, use a 13mm with an extension to remove the steel engine mount alignment plate.



Remove the two lower bolts using a 1/2" drive and 16mm socket If you have to use an 18mm these are the WRONG BOLTS!


Grab your hydraulic floor jack and the 6" 2x4 piece of wood, position the wood and the jack on the rear passenger side corner of the oil pan. NOTE: MAKE SURE THE WOOD IS ON THE EDGE THE REASON IS STRUCTURALLY THIS IS THE ABSOLUTE STRONGEST PART OF THE PAN AND WILL PREVENT YOU FROM CRUSHING IT IF ANYTHING WERE TO SHIFT OR DROP. Once the jack is positioned under the pan lift the engine until the engine weight is off of the mount and so that the engine mount is off the car frame by about an inch.


With the engines weight off of the engine mount use a 1/2" 18mm socket and breaker bar (this is a tight bugger) and remove both of the remaining engine mount bolts.



Slide the engine mount out of its position and remove from he car.




Now carefully raise the engine on the jack until the engine mount bracket hole is exposed so you can get a socket in. Don't worry you will not damage the other mounts in doing this. You may have to raise the engine quite a bit so don't be surprised (your knuckles will thank you the higher you raise it...) Now use a 3/8 drive ratchet and a deep 16mm socket and remove the front and center engine mount bolt and the super secret hidden rear one, this one you will have to find by feel, but I can assure it is there!





Lower the engine on the jack so that you can have access to all four of the allen bolts on the Harmonic Damper. Then use a 3/8 drive ratchet or breaker bar and a 3/8 drive 6mm allen socket break loose and remove the allen bolts. NOTE: DO NOT USE AN EXTENSION OR ELSE YOU RISK STRIPPING THE BOLT HEADS. FYI the cam setting bar will kee the engine from moving. On the manual you could put the engine in gear and keep it from moving by having somebody hold the brake pedal down, so this method works for both but at least the manual tranny folks know there is an option.


Use a 3/8 drive ratchet and 16mm socket to break loose the engine mount but don't remove the bolt yet.









Get a 1/4 drive and a 10mm deep socket and remove the (5) bolts that hold the timing belt cover plates on. Remove the last 16mm bolt holding on the engine mount and push the mount upward to remove the top timing belt cover plate NOTE: THE TOP COVER CAN ONLY BE REMOVED ONCE THE LOWER ENGINE MOUNT BOLT IS REMOVED. WHEN RE ASSEMBLING THE ENGINE THE LOWER COVER MUST BE INSTALLED FIRST FOLLOWED BY THE TOP COVER THEN THE ENGINE MOUNT CAN BE INSTALLED IN THAT ORDER. Also notice the rotational direction of the timing belt. Look for oil leaks or anything that is out of order, now is when you want to find it.




Remove the 13mm nut on the tensioner, and using the 2587 Two pin spanner wrench and relieve the tension on the timing belt tensioner by rotating the wrench counter-clockwise.



Using the 3036 cam holding bar and a 19mm 1/2" drive socket loosen but DO NOT REMOVE THE BOLT ON THE CAMSHAFT. The bolt at the factory was tightened to only 33 ft-lbs. so it should not require much force at all to loosen this bolt. NOTE: I HAVE RUN ACCROSS A FEW BOLTS THAT WERE WAY OVER TIGHTENTED, USE EXTREME CARE IN REMOVING THESE TYPE OF BOLTS!!!! IF THIS IS THE CASE I STRONGLY SUGGEST REMOVING THE CAM SETTING BAR UNTIL THE BOLT HAS BEEN LOOSENED AND THEN REINSTALLING IT.



Install the T40001 puller using the 2 prong puller and one of the single prong pullers (it comes with 2 single prongs and one 2 prong grippers). Install the puller making sure that there is a gap between the washer and the pulley. Use a 17mm box end wrench and turn the puller until the pulley "SNAPS" (it will scare you if you don't expect it) off the tapered end of the camshaft.




Remove the cam pulley bolt, the pulley and the tensioner pulley from its shaft


Holding the engine mount away from the engine slide the old belt between the mount and the block, if you have not noticed yet the mount cannot be removed unless the engine is removed from the car... Remove the belt and inspect it for any cracking or rubbing damage. This is when you want to make sure the belt was wearing normally with only minor cracking or wear marks visible. If any abnormal wear marks are present you need to determine how and where they came from so that you do not install a good belt in a poorly aligned engine pulley system.




The first picture is a shot of the hole the 3359 Injection pump lock in gets installed into. The second pictures shows me using a crescent wrench to turn the center bolt to align the pin hole so that I can insert the lock pin. The last picture shows the orientation of the pin relative to the center of the pump. NOTE: IT IS POSSIBLE TO INSTALL THE PIN TO THE RIGHT OF THE HOLE AND HAVE THE INJECTION TIMING OFF BY ABOUT 30 DEGREES, WHICH HAPPENS TO BE OUTSIDE THE IGNITION WINDOW, A NO START WILL RESULT. FYI DO NOT try and turn the whole motor over using the injection pump center bolt! Use the 3036 tool. Rotating only the pump such as I have demonstrated will not loosen or throw the pump shaft alignment off since I am only turning the pumps pulley with out a timing belt installed.



NOTE THIS IS THE AUTOMATIC TRANSMISSION TDC TIMING MARK. If you look at the first picture notice that the circle is at the base of the window, this is what you want. If you have to turn the crank use a screwdriver and gently push the fly wheel in the direction you need to go to get the TDC in the correct position of the window. Then insert the small screw driver to prevent the flywheel from spinning when installing the new belt.


NOTE: THIS IS THE TIMING MARK ON THE MANUAL TRANSMISSIONS. Make sure the mark lines up with the aluminum tooth at the top of the hole.


This is a picture of the water pump. If you have 120,000 miles or more consider replacing it. It's only a few bolts and a gallon or so of coolant. This is a great time to do the job if you have high mileage.


Here is a picture of the timing belt and its part number for the A4 TDI. I strongly suggest making it very clear to the part supplier what type of car you have. It has happened more than once a part counter guy has looked up and sold the wrong part leaving you with a car that is out of commission and the possibility of facing a backorder!. Take your time when researching the parts and double check you have the correct parts before beginning this job, at this stage in the game is the last time to realize the belt or tensioner DO NOT fit!


Hold the belt up and install it so that the curves go this way, it makes it easier to install the belt around the pulleys.


[b]Holding the engine mount away from the engine slide the new belt back under and onto the engine. Route the belt around the appropriate pulleys, in case you forgot how they go on the lower pulleys here is a snap shot for you:


[b]Install the new tensioner. In this picture you see the two holes on the inner hub at the top of the shaft, you DO NOT want it here. rotate the two holes so that they are at the bottom. Also make sure that the alignment prong is engaged in the slot in the head. Go ahead and install the nut finger tight only.




Starting from the crankshaft and working counter clockwise of the belts path around the pulleys take out the slack and make sure the belt is engaged in all the pulley teeth on all the pulleys. Once you work your way back up to the camshaft install the cam pulley into the belt and slide the pulley onto the cam. This may take a couple of tries but it will go on, the belt is going to be very snug. What you are working against is injection pump pulley. Once you get the cam pulley on install the cam bolt but DO NOT TIGHTEN, make sure it is only finger tight!.

Once the cam pulley is on, loosen but do not remove the three blue bolts on the injection pump. This will relieve the stress on the belt betwwen the injection pump and the camp pulley as well as the lock pin. I suggest getting the new style non-stretch bolts, the older style stretch type were depicted by an "x" in the part number Avoid these if possible. The new style non-stretch are suitable for use on ALL A4 TDI's.

You can visually determine the non stretch style bolt by looking to see if the bolts have threads all the way up the shaft to the integrated washer head, the stretch type threads stop half-way up the shaft. Anyway when you loosen the injection pump bolts remove one to inspect it for the type of bolt installed.

With the 3 pump bolts loosened and the injection pump lock pin installed this will assure you that the injection pump is set within the ignition window. I call the setting "basic" pump timing as it pertains to a mechanical setting rather than anything to do with the ECU or "Basic Settings" as recognized by the VAG-COM. Keep in mind having the pump set with the pin will only assure you the engine will start and run, however it will not give you an optimum setting for efficiency or power. At the end of the procedure I will explain how to adjust the timing using the VAG-COM to get the best power and economy from your TDI.





Snug up the 13mm nut just enough and insert the 2587 Two Pin spanner and rotate the tensioner "CLOCKWISE" until the marks (a tooth and a groove) are lined up as depicted in the last picture. You will notice that when you set the tension the cam pulley and the injection pump pulley will move as you take up the slack, this is the whole idea of doing it this way. The magic is even though the pulleys move the pump, cam and crank all remain in perfect time! Now lock down the bolt "Good'n Tight" is a good torque setting.



Double check that the engine mark is still at TDC, the injection pump lock pin is inserted all the way into the pump, and that the Cam locking bar is fully seated. Now using the 3036 Cam holding bar torque the bolt to 33ft-lbs. I usually add just a hair but under no circumstance should this bolt be over torqued. If it is it can snap the end of the camshaft off, now you have problems.

Torque down the three injection pump bolts where they are at.

Double check that the flywheel is still at TDC.

At this point you have the cam locked down, a small screwdriver wedged in the bell housing holding the flywheel at TDC, the injection pump lock pin installed in the pump and all the bolts on the pulleys tightened. The pulley bolts you want taight at this point are the 3 bolts in the pump, the cam bolt (33 ft-lbs) and the tensioner nut.



Remove the cam lock bar, injection pump lock pin, screw driver in the bell housing. REMOVE ALL THE PAPER TOWELS IN THE INLETS, INCLUDING THEAIR BOX, TURBO INLET, EGR INLET, AND ANYTHING ELSE THAT WAS PLUGGED.

NOTE: INSTALL THE LONG ENGINE MOUNT BOLT IN THE CENTER ENGINE MOUNT HOLE TO PREVENT THE NEW TIMING BELT FROM RUBBING ON THE ENGINE MOUNT IN THE NEXT FEW STEPS.

Using the 3036 holding bar rotate the camshaft counter clockwise ONLY!! or else you screw up the tension that is set on the tensioner!! Turn the camshaft/engine one complete rotation until the the #1 cylinder is back to the "Lobes up" position (FYI you should feel really good compression when doing this however compression goes away valves incorrectly timed do not! If you feel like the engine is hitting a valve turn it back and recheck all your settings and bolts to make sure you torqued everything. In the unlikely event that you got the timing incorrect you cannot damage anything provided you rotate the engine by hand. If at anytime you change a timing setting at the cam recheck the rotational clearance using the 3036 tool and turning the cam one rotation).


Install the front and rear bolt in the vacume pump so that the oil feed does not shoot oil all over the engine bay. Be carefull to make sure the o-ring is not pinched in when tightening it down.

Once you complete a camshaft revolution check that you can see the TDC mark in your bellhousing window, if you do your ready to bump the motor.

With somebody in the car you are going to bump the engine using the starter. The reason is this will get the new timing belt properly centered on the pulleys and allow the tensioner to take up any slack in the timing belt. Try not to let the engine start and bump the engine as many times as required (3-4 times) until the belt stops moving and is centered on the "CAMSHAFT" pulley. The injection pump will be somewhat off center that's totally normal you just want to make sure that the belt is not riding off the injection pump pulley, if it is you need to have the bracket either replaced or reshimmed.

Now that you have bumped the motor clear every intake port once more and start the motor, it should start immediately and run normally, if not recheck all timing marks you missed something. When the engine starts shut it off to prevent oil from going everywhere.

When your closing every thing up a few things to remember:

-Timing belt covers, install the lower cover first, then the top cover then the engine mount.

-When installing the pendulum mount install the steel alignment bracket first then install the big mounting bolts.

-Use blue locktite on the 4 harmonic damper bolts.

VAG-COM timing procedure

Start the engine and let it run. Hook up the Vag-Com and start the software and enter data block 000. Enter "Basic Settings mode". Read data block 2 and data block 9. If block 9 (fuel temp) is reading 110 then block two should be reading 70. I doubt it is since the timing is only set to be in the ignition window so shut the engine down. Loosen the three bolts (DO NOT REMOVE THEM!) on the injection pump. Using your trusty large crescent wrench gently and very very slowely rotate the pump counterclockwise to make the number in block 2 increase or clockwise to make it decrease. Increasing the value of the number in block two will effectively "Advance your timing".

You of course will have to guess at how much you moved the pump, retighten the 3 bolts get in start the engine and see where its at. If the number is not where you want it repeat the procedure until the setting is where you want on the graph in the bentley manual (sometimes I am glad one of my cars is an A3....)

FYI, advancing the timing will reduce smoke output, increase fuel economy, and make the engine more rev happy. It will not matter if you are running the .184, .205 or .216 injectors becuase the #3 injector tells the ECU when injection occurs so the ECU will have all that taken care of.

Break time....my hands hurt
Drivbiwire

GeWilli


hey, nice write up!

As a vindicated "Mark and Pray" method user - meaning I used it and it was proven to be good, but after hearing what happened to a Michigan TDI that went to a Detroit area Dealer, the Timing belt was changed with the "mark and pray" method and the car wasn't the same till Drivbiwire performed an emeregency belt change with re-timing.

IF everyone remembers The Ripster - went to a guy in Ohio to get the timing belt done and it was done super fast! With the factory method.

I have to emphasis - if you are going to be doing your own work on the car it is worth it regardless of the price to get the correct tools, esp if you plan on keeping this vehicle for a while.

The debate about fabricating one - really isn't worth it cause the time spend and the uncertainty factor about the strength cannot be justified by most people - those with home machine shops and 20 years experience . . . well that is different.

getting the belt on with the mark and pray requires strength and luck esp trying to work the belt over the sharp teeth of the camsprocket.

Another thing - you cannot do the factory method using Mickey's 12 point socket to turn the cam. or I should say you had better not! Esp if you need to line the cam and the crank!

Thanks Pete.

The Offical TDI Club A4 Manual Golf/Jetta Video should be availible soon (I hope)


GeWilli


Here are the prices from Zelenda

The VW Factory tools you are going to need are:
$67.30 -3036 Camshaft holding bar
$58.50 -3418 Camshaft setting bar (locking plate)
$19.25 -2587 2 pin spanner wrench (bicycle wrench costs about $7.00)
$12.80 -3359 Injection pump lock pin
$149.50 -T40001 puller set

Total:
307.35 shipping over $300 is free.

anyone find cheaper Prices?

The other tools:
Craftsman Serpentine Belt Tool
Use to release tension on Serpentine belt self adjusting idler pulleys.
Sears Item #: 00941831000
Mfr. Model #: 41831
$29.99

Craftsman
10 x 11 mm Box End Wrench
Sears #: 00944360000
Model #: 44360
$10.99

the bit sockets are generally about $6 a piece from sears.

the one other suggestion for them is to find some 1/4 bits that are 5 and 6 mm and then use a 1/4 socket to hold the bits (Othewise known as the NYTDI solution)

thats it for now - too much parts hunting for me - I hope this helps

Please anyone else with prices for the tools from other suppliers please post them.

Parts Place in Auburn Hills DOESNOT have any of there parts.

Powder Hound


Just a quick comment on the final timing procedure. Turning the center bolt to advance the timing is the clockwise direction when viewed from the passenger side.

Also, since the injection pump pulley turns at 1/2 crank speed, it should be noted that a very small turn (3-4mm travel measured at the sprocket diameter measured by how much the wrench handle moves there) will move the timing figure (the 'A' number from data word 2) about 40 or more. So, be careful and make very small corrections!

mickey
Really, REALLY small corrections! As small as you can possibly make. I think the entire timing range from 0 to 255 covers just 3 or 4 degrees at most. And the "band" considerably less than that. If you even THINK about moving the pump shaft one way or another you've probably made all the adjustment you need to make.

-mickey

BillW
Great Job! I have been thinking about this all morning. The pump on the A4 is bolted down and does not move like the A3 older TDIs. The only part that will move on the A4's injection pump, is the sprocket center bolt and shaft. The belt and sprocket will stay relatively stationary, due to all of the belt tensioning. After the 3 sprocket bolts are loosened slightly, then you can take the crecent wrench and rotate the injection sprocket center bolt clockwise or counter clockwise. Clockwise means the same thing as what the Bentley manual refers to, when they write "to right=advances start of injection". Advanced timing means higher numbers in the Bentley gray scale chart. Conversly, When people say Counter Clockwise, this refers to the Bentley "To left=retards start of injection," which means lower numbers for retarded timing. Drivbiwire has the right idea. If the pump could move counter clockwise, the shaft would be moving to the right which is also advanced timing. This is how the A3s work. Slightly different, but because the pump cannot rotate or move, the shaft has to go to the right(clockwise) for advanced timing. Note this is when viewing the injection pump sprocket straight on looking from the passangers front fender side as viewed in the Bentley manual. I hope this helps and does not create confusion.
NYTDI
GeWilli and others - just to clarify - we found that the following did work to get at the tight clearance allen bolts

1/4" drive screwdriver bit holder used w/ 1/4" drive universal and 5 & 6 mm allen screwdriver bits. The clearance was less than with the homemade sockets but it does work w/o danger of stripping/breaking allen bolts.


Drivbiwire
Buy a 5mm allen wrench and a 1/4" drive 5mm socket. Cut off the end of the allen wrench so that just enough of the wrench protrudes from the socket to fully engage the allen head bolt no more no less just enough to engage the bolt. Use a Dremel Tool cut-off wheel to cut the hardened steel allen wrench and some JB Weld to secure it into the socket. It's very easy to do.

DB