John, it would be a Godsend if you could take some pix when you do this job. Am thinking of tackling this myself and I believe the special tools aren't entirely necessary.
The only info I could find online was this (apologies to the author of this guide, I've forgotten your name and where i found the link
How to change the Timing Belt on an Alfa GT 1.9 JTD 2005.
This past week-end I successfully changed the timing belt on my GT diesel. Although I had the right tools and some procedures I struggled a bit because certain things were either not mentioned or not too clear to me.
This procedure is thus aimed at making easy to perform this task avoiding a couple of hours wasted wondering about something.
1. Tools required.
a. Normal sockets and ring spanners for 10, 15, 17, 19 and 22 mm.
b. Ribe bits sizes M (timing belt cover), M (crankshaft pulley) and M (bracket for the reaction link).. With care you can use Torx bits T40 (timing belt cover), T47 (crankshaft pulley) and T 55 (bracket for the reaction link) instead, but is not ideal.
c. Torque wrenches for 10 to 55 N-m. Ideally these should be very shallow otherwise you won´t be able to use them for a couple of bolts like the timing belt tensioner due to the limited space available.
d. Camshaft locking tool Alfa P/N 1.870.896.900
e. Crankshaft locking tool Alfa P/N 1.860.905.000
f. Calibrated screw for above tool Alfa P/N 1.860.905.010
g. You can see a picture of the tools at: http://home.intekom.com/alberto/Alfa/Timing_Tools.jpg
h. Allen Keys: 5mm and 8mm.
i. Smaller tools, like screw drivers, etc.
2. Parts required.
a. Cambelt P/N 0046791189
b. Cambelt Tensioner P/N 0071747799
c. Cambelt Pulley P/N 0055187100
d. Auxiliary Belt P/N 0055189677
e. Aux. Belt Tensioner P/N 0071747798
f. Aux. Belt Pulley P/N 0046794035
g. Water Pump P/N 046804051
h. Hose clamp, screw type to replace the one in the bottom hose of the radiator. Stainless steel is recommended, like from Hella.
I would strongly advise to purchase the tools as they are available and quite inexpensive, about the cost of an extra pulley.
a. Disconnect the battery
b. Remove the engine cover
c. Remove the engine upper reaction link. It is the short torsion bar on the left hand side of the engine inking it to the suspension strut turret.
d. Remove the Diesel Control Unit. Squarish box with the two large electrical connectors on top situated between the engine and the inner side of the fender by lifting the levers. This is to gain some space.
e. Lift the front right hand side of the car. I use a large hydraulic jack on the inner lifting point and as a safety also put the normal car jack without taking much weight on it in case the hydraulic jack would fail. Remove the right front wheel
f. Remove the plastic cover fitted to the right wheel arch guard that gives access to the crankshaft pulley. You don´t need to remove the wheel arch guard. I did so unnecessarily.
g. Make a diagram of the auxiliary belt layout to facilitate re-fitting.
h. Remove the auxiliary belt by fitting a spanner on the bolt of the pulley and turning it anti-clockwise to the maximum travel. Slide off the belt or better ask an assistant to do so.
i. Remove the auxiliary belt fixed pulley.
j. Remove the auxiliary belt tensioner.
k. Remove the crankshaft pulley. Keep it steady using a socket on the centre bolt.
l. Remove all three timing belt covers. At the point of removing the top left cover it may be easier to remove the bracket on the engine where the reaction link was attached. (Take care not to disturb the separator where the horizontal bolt goes through). Beware that in my car two of the timing belt cover bolts had 5mm Alley Key heads and not Ribe as the rest.
m. At this point you must make sure that you understand the usage of the timing tools and verify the alignment using them.
n. Remove the plug to the right of the camshaft pulley fitted to the engine cylinder head that covers the actual camshaft. Use the 8mm Allen Key.
o. Now fit the camshaft locking tool noticing that the actual plunger is spring loaded so at this stage it does not matter what the camshaft position is.
p. Rotate slowly the camshaft clockwise using the centre bolt until you hear a “click” indicating that the camshaft tool has engaged into the slot of the camshaft. Now the camshaft is locked in the TDC position.
q. Working on the crankshaft pulley, present the locking plate (P/N 1.860.905.000). The longer part should be to the left. Locate a bolt on the crankshaft cover that would be aligned with the hole at the extreme of the tool. Remove this bolt and in its place screw the spindle part of tool P/N 1.860.905.000. Now re-position the crankshaft locking plate and it should be perfectly aligned with the spindle and the plate aligned to the crankshaft by means of the dowel pin on the crankshaft.
r. At this stage you could put the calibrated screw but it is not necessary. You have now verified that you can align the camshaft to the crankshaft.
s. Make a diagram of the timing belt layout.
t. Loosen the timing belt tensioner and remove the timing belt.
u. Now we need to drain the radiator. To achieve this it is necessary to loosen the bottom radiator hose.
v. The factory fitted clamp can be removed by first sliding off the safety curl. Use a flat screw driver and thin nose pliers but be careful that the radiator is plastic. Once this curl is off it is easy to open the clamp at the crimping point. Drain the radiator.
w. Replace the radiator hose and fit a new clamp.
x. Replace the water pump.
y. Here you can see a picture of the water pump removed: http://home.intekom.com/alberto/Alfa/Water_Pump_removed.jpg
z. Re-fill the radiator with 50-50 mix of antifreeze and distilled water.
aa. Replace the fixed timing belt pulley.
bb. Replace the timing belt tensioner leaving the bolt a bit loose at this stage.
cc. Now the timing belt needs to be fitted. Take note that the belt has yellow arrows pointing to the direction of rotation. The arrows must point in a clockwise direction.
dd. The belt also has two yellow lines. Note that both the camshaft toothed belt pulley and the crankshaft tooth belt pulley have each a white mark on the front face next to the teeth.
ee. The mark on the belt closer to the arrows needs to align to the white mark on the crankshaft toothed pulley. Before placing it paint the front face of the belt teeth at either side of the yellow line because when the belt sinks into the teeth you will not be able to see the line any longer.
ff. Now place the belt on the crankshaft aligned to the white mark on the pulley and wind it upwards. The other yellow line will now match exactly the white mark on the camshaft pulley. This is a further confirmation that things are ok. Complete placing the belt around the other pulleys and the tensioner. (If you wish you can also lock the crankshaft for this operation. I found to be not necessary).
gg. Now we need to tension the belt. This is achieved by placing a large flat screw driver between the engine recess and the bent tongue of the mounting plate of the belt tensioner. Make the metal arrow to align with the pressed dot or hole on the same mounting plate (black metal) and at this point tighten the belt tensioner bolt.
hh. Verify that the crankshaft aligning tool still aligns to the spindle. Remove this tool and the camshaft plunger tool.
ii. Rotate the camshaft a bit less than two turns and re-fit the camshaft plunger tool. Continue rotating the crankshaft until you hear the click indicating that the camshaft tool has engaged. Now re-check that the crankshaft tool indicates correctly.
jj. Remove the tools and check that the tensioner arrow is still aligned with the dot. If not re adjust the tensioner and repeat the above process to confirm alignment and tension. Do not check the tension with the alignment tools in place as this will cause a reading error. The timing belt is now ready. (Keep in mind that the yellow lines on the belt will wonder around once you rotate the crankshaft, so those references are good as a second check initially but only your tools will allow to check the alignment thereafter).
kk. Replace the timing belt covers and the bracket for the reaction link.
ll. Fit the fixed auxiliary belt pulley. Fit the crankshaft pulley and also fit the tensioner for the auxiliary belt, this time also tightened.
mm. Now fit the auxiliary belt. You will need an assistant, remembering that you need to place a spanner on the pulley´s bolt and rotate it counter-clockwise to be able to slide the belt in. (This can be the trickiest part of the process!).
nn. Fit the reaction link, fit the crankshaft plastic cover on the wheel arch underguard and re-fit the wheel.
oo. Re-fit the engine cover.
a. Timing Belt tensioner: M8, 23 to 28 N-m
b. Reaction link bracket to the engine: M10, 45 to 55 N-m, all three bolts.
c. Reaction link bolts: M10, 45 to 55 N-m
d. Cranshaft pulley: M8, 23 to 28 N-m
e. Auxiliary belt tesnioner: M10, 45 to 55 N-m
f. Fixed timing belt pulley: M10, 45 to 55 N-m
g. Water pump: M8, 23 to 28 N-m
Which is all very useful, but I need pix!
Will watch this thread with great interest