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Timing Belt Replacement

From Bob Brown:

Hi Doc:

This is what I do; First I put the car in stands (it's easier to work at the proper height)

Then I remove the rear tire, and the distributor inspection cover from the spare tire compartment, then I remove the timing belt covers (top & bottom)

Then remove the water pump pulley and belt at the crankshaft.

Now get to work

First align the mark at the top of the gear cam, mark the position of the rotor on the distibutor

Then, I loose the 17mm tensioner nut, pull the tensioner ALL THE WAY TO THE LEFT, then tighten the nut again (this will keep the tensioner open)

Remove the belt from the cam gear, then from the Aux. shaft and from the crankshaft at the bottom.

To install the new belt; You can drop it from the top, but first you get it at the crankshaft pulley then through the Aux. Shaft gear, being sure that the belt is properly seated on the bottom pulley (no slack)then at last the cam gear (This is the fun part), Be patient and DO NOT use a screwdriver to help you.

Once the belt is installed CHECK that the crankshaft mark is at "0 Deg." (the right mark on the pulley)and also check that the cam gear mark is aligned.

Rotate the engine with the belt at least one complete revolution (It's easier without the plugs) and CHECK AGAIN your timing marks at the crankshaft and cam gears.

If they are Ok, then you can loose again the tensioner nut to re-tighten the belt, then tight the nut again, and that's it!

Now if the rotor on the distributor has moved, simply remove the 13mm nut, raise the distributor a bit and re-align the rotor with the mark you made earlier.

Install again the water pump belt and it's half pulley and now you are ready to set the timing.

Again, at the bottom pulley align the mark with the third left mark on the pulley "10 Deg."

I have aquired some practice in the past years, and I actually find it to be a fun project (actually, the only hard part is getting the new belt into the cam gear)

Good luck, I hope my tip helps.

From Bob Brown:

Some hints. EASY to do with the engine out of the car, but certainly do-able in.

Align the timing mark at the top of the Cam gear with the backplate notch. Take note of the crank pulley timing mark. Should line up as well with its notch. Remove the distributor cap and take note of where it's pointing.

Loosen the idler bearing, (I think a 15mm?) remove the belt and replace with a new one. If you don't accidentally move the cam pulley, simply re-align the distributor to aim to the same place it was before, (this gets you in the ballpark to start your car again later.) then tighten the nut on the idler bearing while using the spring pressure (only!) of the "snail mount" spring pushing up against the backplate assembly of the idler bearing. I don't have a picture handy but you'll see these parts when you get there. Do not over-tighten the timing belt! It should be lightly "snug" if that makes any sense. You don't want it flapping loosely OR so tight as to pull tightly against the cam gear.

Once the belt is in place and tightened down, prepare to re-adjust your timing. It usually needs some adjustment. Small arms a must.

Also... The tensioner for the bearing pokes out the side of the snail mount. After you loosen the nut on the bearing, put a pair of vise grips on that tensioner and pull it toward the trunk, then slide an open end wrench between the vise grips and the snail mount to hold it back. It will make it alot easier to get the belt off and back on.

Also, don't be surprised if you drip coolant while the bearing is loose.

The only thing I would add is when you think you're done, but before buttoning everything up:

  1. Rotate the engine 1/2 revolution
  2. Loosen the tensioner nut (re-tensioning the belt)
  3. Re-torque the tensioner nut

My old mechanic did this and said because you're tensioning a toothed belt at one point only, it's impossible to properly tension the entire belt at once. The teeth prevent the tensioning effects from reaching that portion of the belt that lies opposite the tensioner. He said doing this allowed the "un-tensioned" part of the belt to become properly tensioned. Don't know if he snorted too much Castrol or if it's really necessary but it makes sense and I've always done it...as much out of superstition as anything!