Timing Belt

[Glennb]

i am putting my timing belt back on and as i turn the timing belt, the camshaft pulleys want to spin back.
is this normal?

[rguil]

need more detail to help. When the belt goes on, the cam bar needs to be on. Please tell me your using a cam bar

[Wagonholic]

(if you are using pin and bar)

set at tdc, put belt on, pre-tension belt, torque down cam pulleys, replace crank pulley, remove bar/belt, spin crank 720 degrees clockwise (2 rotations), check to make sure it's all at tdc still

[Glennb]

I'm using a cam bar but when i put the new timing belt on the the left cam pulley was not aligned with the other so i used the cam bar to sync it by using the bar as a wrench.

[Zba]

If you want to do it right you need to pull the sprockets

[Glennb]

If you want to do it right you need to pull the sprockets

i did pull the sprockets

[Zba]

Then you tightened them before pulling the pin on the tensioner

[Glennb]

yeah i tightened them before pulling the pin

- - - Updated - - -

yeah i tightened the sprockets before pulling the pin

[MainThink]

yeah i tightened the sprockets before pulling the pin

Which is not how you do it. The sprockets need to be able to move freely while the tensioner pre-tensions the belt.

[Glennb]

Which is not how you do it. The sprockets need to be able to move freely while the tensioner pre-tensions the belt.

no i take it back, i torqued the sprokets after pulling the pin.

[Zba]

Did you pull the pin, set the preload on the tensioner THEN torque the sprockets all while using the crank pin too?

[sxC]

The way the person above has the right way to do it. Always use the cam bar and locking pin. IIRC from when I assembled my heads and set the timing for the cam chains, at top dead center one of the valves is partially open and so you need a little force to rotate one cam to the right spot. So one head will want to "sit" off of TDC if there isn't a lock bar or timing belt on it. When at TDC the cam won't move on it's own so it's not an issue unless you move the cam without the lock bar on it. Someone correct me if i'm wrong.

Regardless, I just swapped a timing belt today, if you leave the cam sprockets loose and set the pretension on the new tensioner (11ft-lb or something like that) WHILE the lock bar and crank pin are in, and THEN torque the cam sprockets you will be fine. As long as the belt has tension on it before the cams are tight and you're holding everything at TDC with the bar and pin there is no way to mess up the timing.

[Glennb]

The way the person above has the right way to do it. Always use the cam bar and locking pin. IIRC from when I assembled my heads and set the timing for the cam chains, at top dead center one of the valves is partially open and so you need a little force to rotate one cam to the right spot. So one head will want to "sit" off of TDC if there isn't a lock bar or timing belt on it. When at TDC the cam won't move on it's own so it's not an issue unless you move the cam without the lock bar on it. Someone correct me if i'm wrong.

Regardless, I just swapped a timing belt today, if you leave the cam sprockets loose and set the pretension on the new tensioner (11ft-lb or something like that) WHILE the lock bar and crank pin are in, and THEN torque the cam sprockets you will be fine. As long as the belt has tension on it before the cams are tight and you're holding everything at TDC with the bar and pin there is no way to mess up the timing.

i used the cam locking bar and crank lock pin.
i used it when loosening the sprokets and when torquing.
before i torqued them, i noticed that the left cam was not in sync with the right. i used the cam bar to kind of wrench the left cam up to sync with the right. it was giving me a lot of feedback and it wanted to move back to its original place but i didnt think much of it. i got the cam bar on and went ahead with torquing the cams. it wasn't until i rotated the belt wth the crank that i noticed something was not right. the left cam is making the belt want to move back and force from the cam is inconsitent.

im afraid that somehow the timing got messed up.

[killerkali]

Unless im misunderstanding you I think that is normal, every time i did a timing belt the left cam wanted to pop back 30degrees or some when free of the pulley and belt. As long as you use the crank lock pin, and the bar fits after hand cranking the motor over several rotations you are ok. No shortcuts though