Firstly, major kudos to the contributors here. If you’re like me, the biggest challenge with any major car repair is getting past the “what if I can’t handle it” fear. As a casual knuckle buster, this is the first time I’ve worked on this engine. Here are a few tips / notes I can offer that may save the next guy some time & frustration:
1) Heed War Wagon’s recommended tool notes regarding the harmonic balancer! I’ve never seen anything like this in my life. Not only did I shear a ½ drive breaker bar, I also applied a Husky 800ftlbs air impact gun to this bolt and it wouldn’t budge. Penetrating oils? Tried that & failed. Heating up the bolt with a torch? Tried that & failed. Verified the direction of the engine rotation (clockwise from the passenger wheel-well’s perspective), applied a cheater bar to the bolt, pulled the fuel-pump fuse & bumped the ignition several times? Tried that & failed (the cheater bar literally chipped concrete). If you’re going to tackle this project, get the right tools. Don’t make the same mistake I made in thinking I could muscle it off with a ½ breaker bar. Every (wanna-be) mechanic I called looking for a deep-well 19mm x 3/4 drive socket all said the same thing: “Why do you need a ¾ drive? You should be able to get it with a ½ drive,” (emphasis on ‘should’). Wrong! Save yourself the frustration & get a ¾ drive breaker bar, a 20” x ¾ drive extension, and a 6-point, deep-well 19mm x ¾ drive socket (a 12 point will not work – tried that too). I’m sure there are cases where something less worked but if this is your daily driver, chances are, you will not want button the car back up without being able to make the intended maintenance.
Here you can see where I tried to use a 3/4 drive reduced down to 1/2 trying to accommodate the only 19mm deep well socket I had:
Another photo of the sheared adapter:
And here is why you need a deep-well socket:
2) Common sense may dictate this, but by the time I got the bolt loose on the Harmonic balancer, I was so excited that I did not pay attention to the that thin sheetmetal washer in between the harmonic balancer & the crankshaft. Its really more like an escutcheon. The outer circumference of this escutcheon is flared / cupped. The flare faces out. As War Wagon noted, if you install it in with the flare facing in, I imagine it will eat your new timing belt.
3) Before you remove the old timing belt, take the old spark plugs out & leave the new ones out until you’ve installed & verified timing on the new belt. This way, if you miss your marks on the timing, you can rotate the motor without having to fight compression.
4) Also, before you remove the old timing belt, note the positions of the cams & crankshaft relative to Cylinder One TDC (Top Dead Center) marks. I know of some mechanics who disregard these marks assuming that if nothing changes between taking the old off & putting new belt on, timing will be spot on. Maybe I’m too cautious, but working on an interference motor like this, its too risky for my kind. Once you remove the harmonic balancer, you will see the markings on the crankshaft & motor wall for TDC. In my case, the Woodruff Key happened to coincide with the crankshaft mark. I put the harmonic balancer back on and used the special Honda tool to rotate the motor to TDC (clockwise). The cams will match TDC every second full rotation of the crankshaft.
5) I’m one of those idiots who charges ahead and refer to instructions / manuals only after I get stuck. That said, I’m sure there is a precise sequence for routing the new timing belt – nonetheless here is how I did it & got it right the first time.
a. Hand thread the top bolt into the tensioner but leave the lower bolt off until you’ve routed the timing belt. This will give you a little extra slack to work.
b. Start on with the belt on the inside of the tensioner pulley & work your way up to Cam 1 (closest to the firewall). This cam not only has an edge guard, but the head-wall has an obstruction / guide just above the cam with just enough clearance for a fully-seated timing belt.
c. From Cam 1 tightly draw the belt under the water pump, up to Cam 2, down & inside the pulley guide & finishing on the crankshaft. A third or forth hand is extremely helpful, but if you doing this by yourself, you can use desk / office binder clips to keep the belt on the cams.
d. All of the timing belt slack must be between 9 o’clock of the crankshaft an 9 o’clock of Cam 1. Once the tensioner is fully installed & engaged, it will absorb all of this slack. You ready for the secret?
e. I like to cheat (when it means I can win). I imagine there is a iron-grip monster out there that can pull the belt taught in between Cam 2 & the crankshaft but I am not one of those guys. The best I could do was pull the timing belt taught enough to match the belt-grooves & crankshaft-splines peak-to-peak. So with the timing belt on everything but the crankshaft, I hand-pressed the harmonic balancer back on & used the special Honda tool to rotate the crankshaft counter-clockwise (away from TDC) by almost a full tooth (minute rotation - maybe 1 – 2 degrees). Then, harmonic balancer back off, I pulled as much slack out of the right side of the belt and pressed it on the crankshaft. This way, once you rotate the crankshaft clockwise back to TDC, it will absorb the remaining slack on the right side of the timing belt before it engages the rest of the assembly.
f. Swing the tensioner up into place, & insert the lower bolt. Remember: once you pull that tensioner retainer pin, its 2200lbs of game-on pressure! If slack is in the wrong place, you’ll have to remove the tensioner entirely, re-set the hydraulic tensioner pin & start over. They make a special tool for that too, but I've heard a C-clamp works just as well(?).
g. Using the harmonic balancer & the special tool, rotate the crankshaft clockwise through two rotations. Verify both cams & crankshaft line up with TDC. If you’re as good as I am, (jk) everything should line up.
6) I decided to install an Unorthodox Racing under-drive pulley (Part No. CU6141A) in lieu of the harmonic balancer. Brief instructions accommodate this little wonder but(!) there’s only one small problem: you cannot use that special Honda tool to lock that fancy new pulley and crankshaft while you re-install the bolt. Youtube has a video where the mechanic puts the car in 6th gear, applied the brakes, and was able to lock down the crankshaft. Me? Not so much. My car is an automatic. If I may, I’ll save you the frustration of pointless google and youtube research. You’ll only find this tip here. The only way to lock the motor for the proper tightening sequence is to pull the starter and hold the starter gear on the flex-plate with a pry-bar / crow-bar.
7) Moving on to the re-assembly of the turpentine belt assembly, that tensioner is a real bee-ah for two reasons: 1) the lower pulley is the one that has the pivot bolt and escutcheon / washer. I wasn’t paying attention when these parts fell away from each other. I was left scratching my head and googleing images trying to figure out how that escutcheon is oriented –especially because when I put it together like common sense dictated, the washer & the pulley seemed to interfere with each other. I save you another 20 minutes: it goes in between the bolt and the pulley and, just like the crankshaft washer, the flare faces out! This is what I assumed originally but what I didn’t realize while holding the assembly is that the interferences cease, only after the pivot-bolt is torqued down to spec. 2) If you’re doing this project by yourself, applying enough pressure to the tensioner AND trying to route the serpentine belt? It’s nearly impossible. My trick? I positioned the breaker bar on the tensioner and then used one of those ratcheting furniture straps. I ran the strap from the sway bar around the breaker bar & ratcheted them together. The strap held the breaker-bar & tensioner while I finished routing the serpentine belt.
That’s about it folks. Armed with the right parts & tools, a little courage, and a lot of patience, this project is a fun one! Having no prior experience with this engine, it took me right at 10hrs to complete with the upgraded UR Underdrive Pulley (part no. CU6141A). Now that I am armed with the right tools & experience, I would say I could comfortably complete this project again in half the time.
Two side notes:
1) The old serpentine belt and the timing belt matched each other in signs of wear –next to nil. After 98k miles, they could have easily gone another 20k. The only component that showed noteworthy wear was the timing belt guide pulley. I imagine this component would ultimately led to the failure of the others. As Aviography quoted: "You would rather change the timing belt 30,000 miles early than one mile late."
Here is a photo of the soon-to-fail timing belt guide pulley:
2) The ECU is still adjusting to the new underdrive pulley but so far, I am thrilled with the upgrade. The original harmonic balancer weighs 5lbs 9oz. Unorthodox Racing’s underdrive pulley weighs 11.7 oz. By my calculations that nearly an 87% reduction in spooled / torsional weight! Not to mention the reduction in parasitic drag. It’s not a cheap upgrade but I intend to drive this car until my great-grandchildren mock me for it. You can’t put a value on the rush of more responsive acceleration but you can put a value on the more efficient fuel consumption. So I expect my ROI is about another timing belt project away. ☺ Best of luck!
Here is a photo of the UR underdrive pulley compared to the OEM harmonic balancer: