MightyMouse

After reading the manual on replacing the timing belt, I'm not sure if I understand how to set up the crankshaft gear with the tension timing marker on the engine. My question is this, after setting everything up to the proper TDC markings, when I turn the crank shaft sprocket 1-5/6 turns to that tension marker, should the belt be turning the cam shaft sprockets along with it? In other words when I intially place tension onto the timing belt will the camshaft gears still be in their TDC position and the crankshaft still be at the tension marker position?

pschmidt

iTrader: (19)

The camshaft gears will move along with the crank through the 1 5/6 revolutions. Set the tension, turn the crank 1/6 turn more, and with a little luck everything will be back at TDC.

mtncrvr

After you do that - check the marks, turn it and check the marks again and make sure you've got good tension (you really don't want it to slip).

MightyMouse

Thanks for the info.

steelrat

After having a massive tech day this weekend, with 3 TB done.....

Make sure you line the marks up.... E + I on the cams, and the timing gear on the crank. Get the slack if you can over by the tensioner bolt. Rotate the crank around to the tensioner mark (about 10/11 o-clock on the timing gear). Set the tension on the belt. Rotate to 1 full turn to TDC, and check the alignment on everything.

Should be good to go. That said, if something looks out, or you get a bad feel (with too much slack in the belt between the gears) just loosen it, and start over.

We found that holding the exhaust cam still with a 24 or 25/26mm wrench (between cyl 1&2) you can hold it still, while you adjust it slightly to get the teeth on the belt to go on. That seemed to work the best.

Dave,

MightyMouse

Being that the 1.6 is a non interference enigine, when setting the crank shaft to TDC, I noticed that with 1 complete turn the #1 cylinder is in TDC, yet If I make one more turn the #1 cylinder is still TDC how can I tell which TDC should be used with the cam shafts being that they are really not affected by the piston posistions as opposed to their own TDC markings?

Joe Perez

iTrader: (8)

Doesn't matter.

If you logically separate the head from the block, the crankshaft only has one #1 TDC. When the engine is all together, the crank goes through #1 TDC twice per cam revolution, however as far as the crank is concerned there is no difference between the first cycle and the second cycle. There's not a "first" #1 TDC and a "second" #1 TDC from the crankshaft's perspective.

IOW- just set the crank at #1 TDC, align the cams at #1 TDC, and put the belt on.

MightyMouse

Thanks for the inormation I'm so used to working on american v8s, it's been strange and hard working on a car like the Miata that is so simply put together.