DR

I agree, I think the keyway on the crank is partly missing and the damper has rotated.

I would go ahead and remove the pulley/damper and verify.

Edit: Or the outer part of the damper has rotated.

Tampa 928s

Let me make sure, I should place # 1 piston at TDC and since the cams indicate this is correct then remove my HB. What about the cams jumping and hitting the valves while the belt is off. I have no way of verifying or placing it at the 45 degree mark as per the manual to avoid valve damage.

mark kibort

can you explain what we are looking at. as far as I see the cams are aligned to the cam pulley marks and you are off at the crank TDC mark? keep in mind that the alignment of the pulleys can be off even at TDC. Their aligment has to do with belt stretch, head thickness. they can be up to a half of a tooth off, which is 3.75degrees, but near 7.5 at the crank. sounds like you are trying to align the crank harmonic balancer to the cam marks. this is not really possible, as I mentioed, this alignment is dependant on other things. as long as you are at TDC, and the cams are properly timed, the belt alignment doesnt matter.

go to TDC on the crank. see what the marks look like at the cam pulleys. mark them and reinstall the belt according to those new marks.

mk

SharkSkin

It's possible that the rubber has separated from the inner/outer steel on the HB. Give it a light wiggle with a small prybar. Does it always spring back to where it started when you push it around?

mark kibort

If the car was running, and running decently, things are probalby aligned correctly. it will run with on cam off by one full tooth, but not 2 or 3. at 4 bad things happen at near 4 teeth. So,you can rotate the engine so that the 45 degree mark lines up and then you can do your disassembly. remember its 6 teeth advance at 45 degreee crank advanced. at that point you can lock the flywheel and start pulling things apart and move the cams around. I usually, put vicegrips on the big bolts on the cam pulleys so that when pull the belt off, the cams dont snap one way or the other (usually the driver side cam is spring loaded to snap) Just in case.

mk

mark kibort

If this is true, you have to mark things best you can . I would try to move the balancer. I find it hard to believe that the crank doesnt have a key way. the cams would be way off a the main drive gear would shift too.

I think we need a picture of the car at TDC on the damper and show the misalignment on the cam pulleys. from the black and red marks looks like he is only less than 7.5 degrees off, which would be around a half of tooth pitch.

mk

DR

Mark,

You are correct, maybe part of the keyway is broken off (or wrong one in place) or the outer part of the damper has rotated. I clarified my ealier post, just got back from a long drive with car hauler and my mind is road rashed.

Larry928GTS

Sorry for going off topic on this, but in looking at the pictures, isn't the end of the water pump shaft usually flush with the front surface of the water pump pulley?

Tampa 928s

My brother bought this car non running, got a new fuel pump, filter, cleaned Inj, fixed a ton of intake leak's and replaced the intake boots. It idled fine with a little skip but the wires are toast and rotors and caps are completely worn out as we found out today. The belt was way loose which I thought it had slipped. But after finding the cam marks spot on and the my crank reference line moving as I rotated the crank seems like the Hb is either slipping on the key-way or on it's self. As I said I am going to go with the cam marks and # 1 @ TDC as a starting point. Is there a position of the key-way slot at TDC like straight up or down?

Tampa 928s

Let me be clear, the red and black mark I made when the cam marks were correct. The reason for the read and black is to show if the Hb was slipping as I turned it over. My gut was correct, It was a third away from the HB from the actual marks on the HB, one time on the red one time on the black . It is 7.5 teeth off on both cams not 7.5 degrees off at oTdc on the HB.

SharkSkin

I just noticed that the oil spot on the pulley just forward of the HB is all over the place compared with the timing marks on the HB. If you're turning it by the crank bolt, it's hard to imagine the pulleys slipping(unless the washer is upside down). See if you can grab the HB and move it without turning the crank; also see if you can grab the pulley and turn it without turning the crank.

Mrmerlin

I would venture a guess that you may need to replace the crank damper as it may have broken its bond on the rubber interface.
If the engine runs in its present condition that means that the timing is correct but the marks are not so you can verify TDC with a short rod placed into the #1 cylinder and the cams at TDC, with that done simply make a new mark for the TDC on the crank pulley and then you can remove it or then you can figure out where to place the crank so its at 45 degrees or use your painted marks on the cams

Tampa 928s

Quote:
remember its 6 teeth advance at 45 degreee crank advanced. at that point you can lock the flywheel and start pulling things apart and move the cams

Should I count 6 teeth from the measured Tdc on piston # 1 to establish the 45 Degrees BTDC to make sure the cams don't crash if they rotate.

Tampa 928s

Hb is completly loose and can be turned by hand "nice".

docmirror

Ok, forget the 45deg marks. Set the TDC by the screwdriver in the plug hole method and lock it there. Now, look for the small V notch in the cam gears on the BACK side of the cam gear, not the large notch on the front. The small V notch should be very close to the reference mark notch on the backing plate.

At this point, you can take the belt off, and the HB and start assembling new parts. HB, cam gears, belt, oil pump gear, etc. The exhaust cam will likely sproing when you take the belt off but it won't cause any damage. There is an anti torque large hex nut under the rotor. Use a wrench on that to remove the cam bolt. Put all your new parts on and get the new cam gears in the middle of the adjustment range window slot for the rotor screws.

Now put on the new HB, and torque it down. Then check your TDC using the new HB. You may need to move the crank slightly to realign it perfectly. This should be done carefully if one set of valves are in contact with the pistons. Using the large wrench on the cam gear, you can rotate the cams either left or right as needed to obtain clearance. For example, if the crank is now showing 3deg CCW, you will have to move it CW. You would also plan to move the cams CW which will take at least two people. It's likely that neither of the cams are in contact with the pistons but use caution to be completely sure.

Lock your crank at 0TDC, and install the belt. The cams may be a few degrees off at this point. Use the Porken tool to verify alignment. If they are off slightly, this is the hard part. You'll have to find a way to move the cam while the bolt is loose to make the marks line up. I haven't found an easy way to do this yet. So far, I've just moved the gear using the crank bolt, and then tighten and recheck at TDC. It's a hassle but it works. Do the left side first, then do the right side. Once you have it real close, turn the crank two revs and recheck with the Porken tool. Proceed with the rest of the TB job from there.