RobzWorkz #3: 328 Basic Timing Belt Service

Greetings FChat!

I'm in the process of replacing parts for my rear suspension (threads to come) and decided to include a basic timing belt replacement effort. The main reason to include this procedure at this time is that ALL THE SUFF IS OUT OF THE WAY!!! Thus it's a no-brainer to check/replace the timing belts and tensioners. Additionally, I decided to clean/inspect the alternator (actually called a generator since the VR is included in the assy.).

The first two pics show that I have a lot of room to work on the timing belts and include myself in the wheel well (of course, I'm the tool here).

BTW, to get to this condition (as if you need to arrive at this point having a car fully assembled), place car on jacks, remove the wheel and wheel well components, remove the air cleaner and side duct, unbolt the AC compressor (keep track of shims, etc....Birdman's write-up is good on this one; just hang the compressor by the AC lines; personally, I removed the AC system so as to have better in-car engine access and will derive a modern AC arrangement later) and open the decklid so as to have better lighting and access from above. BTW, BE SAFE AND PREPARE PROPERLY: I TAKE NO RESPONSIBILITY FOR YOUR STUPIDITY AND LACK OF PREPARED-NESS!!!

At this point, I detected that I would need to drain some coolant and displace the coolant hose in order to remove the forward timing cover and the alternator. This mess is shown in pics 3 and 4. Pic 6 shows that I could use paper towels to plug the coolant linnes so as to move the pipe out of the way.

Removing the alternator is simple: disconnect the cable from the starter, disconnect the plug for the ALT light and unbolt the thing. This is shown in pic 5.
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The alternator/generator get dirty over time and mine needed cleaning!

Pic 1 shows dirty.
Pics 2 and 3 show cleaned.

Note, I am NOT restoring the alternator, just cleaning and checking that it's OK. Restoration would be needed if it didn't work and I desired it to be concours prestine. Obviously, I'm not doing this...my alternator works fine.
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Of course, the reason I removed the alternator (and its belt system...DUH!) was because it was attached to the front of the forward timing cover.

Now, it's time to remove the timing covers and gain access to the belt systems.

Note: to remove the rear cover, it is necessary to remove the water pump belt and pulley with its bracket...easy to do.

Pic 1 shows the forward cover removed with alternator bracket. Pic 2 shows both the covers removed and ready for painting. To paint, be sure to abrade with sand paper (120 grit with a sander is good), prep with a cleaner/drying agent (PREP-ALL is good). Pic 3 shows primer paint applied. Pic 4 shows Aluminum engine pain applied.

Note: I didn't paint the brackets; I believe in leaving these alone. Also note that, since I wasn't concerned about the AC compressor mounting, I went ahead and painted the studs for the AC cmpressor: If you are keeping your compressor, then tape over the stud threads!!!
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To be properly able to change the timing belt system, it is essential to verify the timing condition. First, it is important to know how to set the engine in the TOP DEAD CENTER WITH PROPER CAM PHASE condition. For this condition to exist, the crank shaft must be at TDC and the cam shafts aligned for proper orientation.

The crank shaft is aligned by viewing the edge flywheel from inside the access port just below the oil filter: the mark for PM 1-4 should be observed when the crank is at TDC. Pic 1 shows the access; pic 2 shows the cleaned-up access cover. Pic 3 shows the (faded) yellow marking from a previous maintenance effort where color was directly applied to the flywheel.

I had to spend some quality time assessing that the yellowed area corresponded with the TDC condition of the crank, namely the PM 1-4 marking. This was very hard to see for my flywheel, so I had to assess with repeated rotations of the crank shaft. My belief is thus that you need to remove the engine to fully determine the PM 1-4 alignment, unless you are fortunate to be able to see it with the engine in the car. Since my engine ran correctly prior to the timing assessment, I was able to validate the crank shaft position with significant effort. DO THIS AT YOUR OWN RISK!!!

After assessing the crank shaft TDC position, I ground a small ridge marking into the harmonic balancer so as to always visualize the crank TDC position. This is seen in pic 4. I used the two marks on the engine timing gear housing to align my mark.

To verify the cam shaft positions, inspect the rear bank cam shaft positions through the oil cap and the marks on the cam relative to the pointers attached the the timing back plates (the plastic plates attached to the covers behind them looking from the inside of the passenger rear wheel well). Pic 5 shows the view through the oil cap. Pic 6 shows the timing pointer on the plastic back pointing to the cam mark. Viewing the forward bank was unavailable for me, so I had to make assumptions therein since my engine ran properly. SPEND A LOT OF TIME WITH THIS ASSESSMENT!!!
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Now is the time to lock the cams into postion so as to remove and replace the timing belts.

To lock the timing pulleys (on the cams), I fabricated a steel plate/screw tool to hold into place. Pic 1 shows the tool. I placed a lot of duct tape on the steel plates so as to prevent metal-to-metal contact with the cam pulleys. Just tighten the bolt to hold the pulleys in place during the belt/tensioner maintenance. Pic 2 shows the locked cam pulleys (PLEASE DISREGARD THE MARKS ON THIS PIC SINCE IT WAS TAKEN AFTER ROTATING THE SYSTEM).

Place silver Sharpie marks on the cam pulleys, the timing gear pulleys, the timing belt, and the plastic backing so as to be able to align the pulleys and the timing belt as installed. Pic 3 shows silver Sharpie marks on one of the timing pulleys and the timing belt simultaneously. Pic 4 shows the silver Sharpie marks for the timing gear with the belt. Pic 5 shows the marks on the plastic backing: these marks will be used for assessing the cam pulley timing locations.
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The tensioner pulleys are different for the two timing belt networks. Remove the tensioner assemblies when the belt for each (forward and rear) network is sufficiently held with the pulley lock mechanism. Pics 1 and 2 show the tensioner assembly for the rear timing network (smaller mountings), Pic 3 for the forward (around the AC syatem) network with bigger mountings, after cleaning.
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After removing the tensioners from each side, clean them, remove the old pulley and re-install a new pulley (with bearing, of course). Be sure to add caliper grease to the new pulley in the tensioner. Also add grease to the spreng and assembly (after cleaning of course).

Pic 1 shows the pulley mounting bolt with shaped washer. Pic 2 shows the difference between the old pulley (on bottom) and the new one (slight variation in pulley diameter). Pic 3 shows the new pulley/bearing in the tensioner assembly. Note: if you review Birdman's procedure, he cautions you to avoid forcing the pulley/bearing in a way so as to cause the bearing to fall apart; I didn't have any issue of this sort with my replacements. I did, however, have to press out the old pulley/bearing and press in the replacement...just be careful here and press with the INNER RACE only!

Pic 4 shows the cleaned assembly for the rear tensioner mechanism. Pic 5 shows the high-temp caliper grease I used for re-assembly. Pic 6 shows the grease on the spring. Pic 7 shows one view of the unassembled tensioner. Pics 8 and 9 show views of the assembled tensioner with grease applied. Note that, after assembly, the tensioner is very stable...it will hold itself together as shown.
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After removing the tensioners, you can remove the old belts.

Note that, if you are NOT replacing the tensioner bearings (this is undesired), you can simply loosten the bolts retaining the pulleys and push the pulleys away so as to loosten and remove the belt (this is in accordance with the shop manual procedure), and re-tighten the bolt with the pulley in the loosened position. Pic 1 shows the bolt to be loosened. Pic 2 shows me pushing the pulley to the loosening position. Pic 3 shows that the bolt was re-tightened with the pulley in the loosened position (note the washer position relative to the inner race). Pic 4 shows the belt relaxed and able to be removed. Do this if the pulleys are ready for loading after the belts are replaced.

Otherwise, replace the restored tensioners while replacing the belts.

To properly replace the timing belts with new ones, mark the new ones just as you marked the old ones. Pics 5 and 6 show that the new belt is marked as the old one. Note that I provided a reference called "TOP" so as to properly align the marks. Be sure to account for the number of teeth in the belt for each mark spacing.
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Assuming you have set the engine at TDC and set and locked the cam shaft pulleys at their marks, you can now install the new timing belts. You should be able to simply install the new belts so that all the marks line up. However, it is possible that the old belts streched enough that the teeth do not line up, or, you lose the cam pulley alignment by making some mistake. To mitigate any issues, you may have to "tweek" the crank shaft with a wrench/socket and/or manipulate the cam pulley(s) with a ratchet. Anyway, after all is said and done, you will have installed the timing belts so that the marks align. TAKE YOUR TIME!!!

After installing the timing belts, it is now time to load them by releasing the tensioner bearings/pulleys.

Birdman describes 2 ways to load the belts: 1)the Ferrari way, which is to release the timing system altogether, including the tensioner (meaning that it's self-adjusting...not removed) and rotate the crank until the maximum load is applied onto the tensioners (actually, the workshop manual says to rotate the crank two turns which loads the belts and then torque the bolt over the tensioner pulley/bearing to the 40.5 ft-lb spec), and; 2) the Verrell way, which is to rotate the belt system in the clockwise direction (forward-rotate) WHILE THE CAM PULLEYS ARE LOCKED, and effectively loosen the belts at the tensioner pulley thus loading the belts as much as possible; then torque the pulley bolts to 40.5 ft-lb. Both of these methods seem to be acceptable. The basic idea is to let the tensioner spring fully load the timing belt and then lock the tensioner pulley into place by torquing the pulley bolt to 40.5 ft-lb. It is essential not to add additional pressure to the belt in addition to the tensioner spring so as to prevent premature belt failure.

After this, it is time to verify that the engine is properly set up: using a breaker bar and the appropriate sized socket, rotate the crank shaft two turns and verify that the marks on the timing gears and cam pulleys line up (the marks on the belts will travel, so don't watch them). Do this a few times until you are satisfied that the engine is safe to run. Note that any "hard stops" indicate that the valves have touched the pistons...SEEK HELP if this happens.

After the belts are installed, loaded and the pulley bolts torqued, it is time to reinstall all the rest (timing covers, alternator, and water pump mechanisms). Also, it is time to refit the coolant pipe and replace any coolant removed.

Pic 1 shows the reassembled timing covers with the alternator and water pump hardware reinstalled (belts came later after cleaning/prepping for them). Besure to set proper tension on the belts and torque the bolts accordingly. Pics 2 and 3 show how I improvised a funnel to make up the coolant I drained from the pipe: basically, I use a small tube that inserts into the bleed screw hole and attached the tube to a funnel using an interim tip from an RTV kit.

After all is done here, and before replacing the air cleaner and duct, test run the engine and warm it up. I did mine and all went well.

Enjoy FChat!

Rob H.
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Here are some diagrams sutable for reference, etc.

Torque values were taken from the 328 Technical Manual. Fellow F-Chatters, please confirm the torque values. I will update if mistakes are present.

Pic 1 shows the timing system (figure from T Rutlands site...thank you).
Pic 2 is the belt layout (figure also from T Rutlands). Note the belt arrangement. It is also a good idea to replace the drive belts.

Final caveats:
1. After I inserted the forward timing belt, I turned the crank to check that the marks would all line up (after two turns clockwise-from TDC to TDC) and to check/set the max spring load in the tensioner. I did this too fast and the system recoiled and skipped teeth. The lesson learned here is: WHEN CHECKING THE TIMING OF A BELT AND LOADING THE TENSIONER WHILE TURNING THE CRANK SHAFT CLOCKWISE, TURN THE SHAFT SLOWLY AND KEEP YOUR FREE HAND HOLDING THE BELT IN PLACE! If you do lose belt alignment (skipping teeth), you will have to carefully reset it; if you didn't mark the alignment positions, you may have to remove the engine to be able to see the (tiny) marks on the forward camshafts (that's a big oops!). Basically, iteratively rotate the crank with the large socket and rotate the cam pulleys with a small socket untill all is aligned: the crank will stay in place at TDC, but you will have to hold the cam pulleys in place since they have the valve train spring loaded (I used small wood block for this). The reason for iterating the adjustments is that you may cause the piston to touch a valve (3.2 is an interference engine); if this happens, you will have to back track a little...do this slowly and methodically...and do not force the rotation at a stop (piston touches a valve).


2. Do not use a belt if it gets cinched (bent tight). Replace it! This happend to me during my first attempt to restore the timing after the teeth skipped. I bought a new set from T Rutlands from ebay at a great price.

3. Allow only the tensioner spring to load the timing belts. Do not add force to a belt by pushing on the tensioner. Basically, just be sure that the belt is spring tight for all crank shaft rotational positions. When the tensioner pully bolt is torqued, it will not move to adjust itself. Both the 'Verrell method' and the 'Ferrari method' mentioned by Birdman ensure this. This caveat is also stated in the workshop manual.

4. Proper crank shaft rotation is CLOCKWISE when viewing the harmonic balancer.
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This is actually a good question. Basically the pulley hole is oversized and thus there is room for it to wiggle about. When torqued, the bolt, large washer and shaped washer work together to hold the pulley in place at its inner race. There is also a slot in the pulley retainer which sets the direction of motion along the spring force path.

 

No, two crank shaft turns bring the engine into the same configuration. For the standard Otto cycle (4 stroke), the crank turns 2X while all the cams turn 1X. Actually, TDC is generally defined as when #1 piston is at its highest point in the cylinder, which happens 2X during the Otto cycle. That is why the phrase TDC with proper cam phase was used.

Rob H.

 

Absolutely!

However, I don't have a media blasting system. My next choice was thus to paint since the covers looked horrible.

 

Good pic, Steve; it does show the spring travel slot. You can also see that the bearing/pulley has an inner race diameter that is larger than the mounting bolt. BTW, the spring bodies are identical in this pic; is this for a 308? The 328 bodies are of different thickness forward and back, with the forward body much thicker (thus not interchangable).

 

Can't tell you, Steve. I just used something that I know wouldn't decompose at higher temps and would still preserve the insides of the assembly. Recall that, after the pulley is torqued, the spring is locked into position and thus is not really used.

I tend to use white lithium in small gear networks like in fishing reels and such, where temperature is ambient.

 

They are different than the ones in Steve's pic. Pic 1 is the 328 version. Pics 2 and 3 show the assembled tensioner. The pulley carrier moves freely along the slot and is retained by the protrusions in the tip and in the carrier.

Just be sure to learn the configuration of yours when disassembling.
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