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| Joined: | 05-01-2005 |
| Location: | Minneapolis, Minnesota USA |
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What I have had to do is rotate the cam pulley half a tooth or so CW, install the pulley over the cam teeth, then rotate the cam back to where it should be, removing the slack in the belt.Tom.
That's correct procedure. All parts in the engine have dimensional tolearances, and in an assembly the tolerances are additive. As a result, it's highly unlikely that with the crank at TDC, and the pulley timing dots perfectly aligned, that the belt's and pulley's teeth will perfectly align and drop together. And then there's the matter of pulling all the slack out by hand... it can be difficult.
As you wrote, put a wrench on the exhaust pulley's retaining nut, and turn the pulley clockwise (as viewd from the front) toward the crankshaft 'just' far enough to engage the first available belt tooth. Then turn it back, pulling the slack out of the long run to the crank, and putting a little bit of tension in it... but not enough to pull the crank away from TDC.
Then repeat for the intake pulley.
The belt is very stiff side to side. If you slide it fully onto the exhaust pulley first, then it's too stiff to make a zig-zag move to align with the intake pulley. Instead, slide the belt onto the exhaust pulley only 3/8 to 1/2 inch... just enough to engage firmly. Then repeat the pulley rotate-hook-pull with the intake, leaving both only partially engaged with the belt. Hold the belt in place with a little tension toward the auxiliary pulley.
Then switch to the tensioner-side of the engine. Pull the run of belt from the crank sprocket firmly up and around the tensioner, only partially engaging it. Finally, pull the belt strands from both sides toward the auxiliary pulley.
Rotate the auxiliary pulley as required to ensure that the distributor's rotor is where it needs to be for correct ignition timing, then slide the belt loop onto the aux pulley.
Only now, with the three sprockets and the tensioner partially engaged, do you go back and push the belt all the way onto them all.
Crank some strong tension into the belt, enough to pull out all slack and add some strong tension. Don't sweat 'correct' tension for now, just strong tension. Now, make certain the crank is still at TDC, then double check the cam pulley timing dot alignment on the imaginary centerline between the cams. If the dot alignment is a mis-match, or not on the centerline, then go back and fix it now.
When all the pulleys are correctly aligned with the crank at TDC, rotate the crank through two full revolutions, and back to TDC. Have the spark plugs all out so a minimum of force is required to turn the crank. Rotate it with a little mechanical empathy, 'feeling' for the crank to cluck to a stop. That would be a piston hitting a valve... don't force it! Stop immediately and figure out where you went wrong. If you get through two full revolutions without clunking to a stop, and all the timing marks still align, then the belt installation is correct.
Now properly tension the timing belt. Use a gauge and the tension values given in message #4.
*~*~*~*
One more point (I sound like Columbo).
Even with the tensioner backed off all the way, there's NOT a lot of slack in the belt loop. It can still be a bit of a struggle to get the belt stretched onto the auxiliary pulley.
While the belt is very limp radially, it's very stiff if you try to bend it across it's flat strand width. Use that against it.
Pull the loop up onto the auxiliary pulley as far as you can, engaging teeth on either side as far up as you can. More than likely, there will be the last little bit in the middle that will be a bugger to get up onto the pulley.
Leaning in over the left fender (wing), facing forward, left hand nearest the intake pulley and right hand nearest the tensioner... lay one hand on the the top/OD of the aux pulley, where that last, obstinant bit of belt loop is, with your fingers extending past the front edge of the pulley by about two knuckles.
Bend your fingers, folding the top of the belt loop over, laying the belt flat against the front of the pulley. Bend your fingers at the last (outer) knuckle, hooking the edge of the belt, and pull up firmly. The belt, being stiff the flat way, will slide up the face of the pulley until it's edge just barely passes the diameter of the pulley. Not by a lot, just barely, but it's enough.
Now pull/rotate the belt loop back up to a horizontal position, catching the edge of the pulley, and slide the belt back onto the pulley. Do that as one dance move... pull-rotate-slide, and the belt will go right on. Actually, with practice, the whole procedure is 'one move' that takes less than a second... fold-pull-rotate-slide. It goes right on every time.
Regards,
Tim Engel
Last edited on 06-08-2019 04:30 am by Esprit2