Timing belt is tight

I loosen the tensioner yet when I try to put the belt it’s super tight and won’t let me put it over the crankshaft; do y’all have any tricks to let me manage to put the belt over the gear

The timing belt is usually wrapped around the crankshaft sprocket first.


I’ve try that too and it’s still to tight; I’ve zip tied the cam so It won’t move; I’ve tried many ways and still tight

What year and engine?


Normally the last pulley you install any belt over is a smooth pulley…

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It’s a 4g64(2.4L) 2003 Mitsubishi eclipse;

Wrap the timing belt around crankshaft sprocket first.

Then around the oil pump sprocket.

Then around camshaft sprocket.

If the belt doesn’t line up with the teeth on the cam sprocket, turn the sprocket slightly backwards so they do.

Now turn sprocket back so timing marks line up.

Now all the slack in the timing belt will be at the tensioner.


Sounds like OP is a tooth off…

If after that you’re still having trouble, go back and triple check they gave you the correct belt.

The last time I bought a serpentine belt for my truck, everything seemed OK until I went to put it on. It was super tight but fit with the tensioner cranked almost all the way. I looked up the belt number and it appeared to match. Fast forward a couple years and I just bought a replacement as the tensioner was getting loud. The number was slightly different. When I looked up that number it became clear, the older belt was for a different model/trim and was about an inch smaller. The wrong belt pops up first in a search for some reason.

Idk man ive tried to put the belt for the past 2 days I’ve tried every method I’ve been told. I’ve put the belt on but when I put tension the crankshaft moves then Im off by like a tooth or a half but when I start with a tooth off and I put tension the crankshaft doesn’t move so at the end I’m still one tooth off

I’ve compared it to the old belt and the new one is a little smaller maybe by 2 cm; Is that a big differences? or is the old one just stretched

You should have the same amount of teeth on both belts… Lay one on top of the other and make sure the same teeth, or count them…

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If a sprocket moves when the tensioner is applied to the timing belt, it means there’s slack in the timing belt other than under the tensioner


2 cm stretch would be pretty huge IMO. Use the method davesmopar suggested to compare them. The number of notches shouldn’t change :wink: I’m betting it’s not right but I’m a skeptic now :rofl:

Just curious, what is the belt number they gave you?

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How do I prevent this? How do I keep the tension only in under the tensioner

By the method I described.

This ensures there’s no slack in the timing belt other than below the tensioner.


A lot of times it is the cam gear trying to move under valve spring pressure under load from one of the valves being open and you have to lock the cam down…

EDIT: with out the belt on does any of the gears try to move when 100% lined up (timing marks)???

Ok thanks for the help!

No only when the belt is on and the one that moves the most is the crank

Try removing the spark plugs, will get ride of any possible compression turning the crank…

EDIT: you might need to install the crank bolt a little tight and use a socket and breaker bar or wrench to hold it from turning while you route the belt…