UPDATE:
I am a moron - I had the timing belt on backwards - the arrows should point to the timing marks on the FRONT of the crankshaft cog and camshaft sprockets, not the REAR timing marks. I incorrectly assumed that the "MITSUBOSHI" text on the belt would be oriented to face toward the front of the rig, but that is not the case. I have no idea how I got all of the timing marks on the belt to align correctly with it backwards, but it clearly put too much tension on one side and that it why the belt jumped teeth as I turned the engine by hand.
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[TL;DR - timing seems to be off by about 18 degrees after new timing belt install - how do I safely remove the timing belt, readjust the position(s) of the cam sprockets relative to the crankshaft and attempt to reinstall the timing belt?]
Decided to take the plunge and do a PM replacement of the timing belt, fan bracket, water pump, cam and crankshaft seals, etc. this weekend. Everything seemed to be going well up to installation of the timing belt. Per the FSM, OTRAMM's video, and the various posts I read here, I aligned the timing to the 50 degree mark (harmonic balancer mark pointing to pully bolt) and when mounting the new belt I lined up the marks on the timing belt first on the crankshaft, then on the driver-side cam sprocket, and then when attempting the passenger-side cam sprocket, things ran off the rails a bit. The best I could do on aligning the passenger-side sprocket with the corresponding mark on the belt was off by 3 sprocket teeth, so I rotated the driver-side cam sprocket counter-clockwise a bit to provide enough slack to allow me to mount the timing belt on the passenger-side cam sprocket with the markings aligned.
Double checked everything and all marks lined up. Installed the tensioner, pulled the pin, and inspected the tension on each segment of the belt - the section between the crankshaft up to the passenger-side cam sprocket seemed slightly more slack than between the cam sprockets and between the driver-side cam sprocket and the crankshaft sprocket. Perhaps unwisely, I assumed "good enough" and pulled the pin on the tensioner, and then rotated the crankshaft two revolutions. When I first applied force to turn the crankshaft, I felt a shift that I perceived as the belt teeth slipping a few notches. Sure enough, after two full rotations of the crankshaft, the harmonic balancer mark is retarded by about 18 degrees relative to the marks on the two crankshaft sprockets, as shown in the attached images.
I've perused the forums and other online sources, and there is a lot of information on how to verify good timing, but I can't find much on what to do if timing is verified as bad.
So my question to those experienced in such matters: how do I safely remove the timing belt and adjust the relative positions of the camshaft sprockets and crankshaft crocket to remount the timing belt with the correct timing? Can I simply remove the timing belt, rotate the crankshaft sprocket almost two rotations so that the harmonic balancer mark lines up with the zero on the timing indicator, and then remount the timing belt and test again? I see conflicting information about whether the non-vvti 4.7 is an interference engine or not, and I dread bending valves by screwing around with the positions of the cam sprockets.
I am a moron - I had the timing belt on backwards - the arrows should point to the timing marks on the FRONT of the crankshaft cog and camshaft sprockets, not the REAR timing marks. I incorrectly assumed that the "MITSUBOSHI" text on the belt would be oriented to face toward the front of the rig, but that is not the case. I have no idea how I got all of the timing marks on the belt to align correctly with it backwards, but it clearly put too much tension on one side and that it why the belt jumped teeth as I turned the engine by hand.
_________________________________________________________________________________________________________________________________________
[TL;DR - timing seems to be off by about 18 degrees after new timing belt install - how do I safely remove the timing belt, readjust the position(s) of the cam sprockets relative to the crankshaft and attempt to reinstall the timing belt?]
Decided to take the plunge and do a PM replacement of the timing belt, fan bracket, water pump, cam and crankshaft seals, etc. this weekend. Everything seemed to be going well up to installation of the timing belt. Per the FSM, OTRAMM's video, and the various posts I read here, I aligned the timing to the 50 degree mark (harmonic balancer mark pointing to pully bolt) and when mounting the new belt I lined up the marks on the timing belt first on the crankshaft, then on the driver-side cam sprocket, and then when attempting the passenger-side cam sprocket, things ran off the rails a bit. The best I could do on aligning the passenger-side sprocket with the corresponding mark on the belt was off by 3 sprocket teeth, so I rotated the driver-side cam sprocket counter-clockwise a bit to provide enough slack to allow me to mount the timing belt on the passenger-side cam sprocket with the markings aligned.
Double checked everything and all marks lined up. Installed the tensioner, pulled the pin, and inspected the tension on each segment of the belt - the section between the crankshaft up to the passenger-side cam sprocket seemed slightly more slack than between the cam sprockets and between the driver-side cam sprocket and the crankshaft sprocket. Perhaps unwisely, I assumed "good enough" and pulled the pin on the tensioner, and then rotated the crankshaft two revolutions. When I first applied force to turn the crankshaft, I felt a shift that I perceived as the belt teeth slipping a few notches. Sure enough, after two full rotations of the crankshaft, the harmonic balancer mark is retarded by about 18 degrees relative to the marks on the two crankshaft sprockets, as shown in the attached images.
I've perused the forums and other online sources, and there is a lot of information on how to verify good timing, but I can't find much on what to do if timing is verified as bad.
So my question to those experienced in such matters: how do I safely remove the timing belt and adjust the relative positions of the camshaft sprockets and crankshaft crocket to remount the timing belt with the correct timing? Can I simply remove the timing belt, rotate the crankshaft sprocket almost two rotations so that the harmonic balancer mark lines up with the zero on the timing indicator, and then remount the timing belt and test again? I see conflicting information about whether the non-vvti 4.7 is an interference engine or not, and I dread bending valves by screwing around with the positions of the cam sprockets.
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