Cam Seal Replacement Question

[TMan]

During a timing belt replacement scenario (cam seals, crank seal, water pump etc).....

I have the bolt to each camshaft pulley "broken free", but before I remove the timing belt I want to ensure that the cams are held "in place". I plan to secure the camshafts since I have the valve covers off to replace gaskets there.

What I would like to know is with all timing marks aligned, which way each cam might try to turn. Actually I guess the two on the drivers side with lobes pointed into the lifters look like they are "loaded".

I am guessing that the top cam may try to turn CCW and the bottom cam CW?

May be crude but I am thinking about locking them down by clamping a vise grip (rubber buffers in grip area) on the "cast" non journal section of the cams but want to get the direction correct.

Thanks

[nipper]

it really depends where they the cam lobes are positioned, and how many valves are opening and closing. Murphies law is no matter what you try, they will move at some point.

 

nipper

[a97obw]

With the crank and cam marks properly aligned as if you were going to merely replace the timing belt, the pistons are just past mid way up the full stroke. I.E. the valves are not going to crash into the pistons. Should one of the cams decide to suddenly (and believe me, it will be "suddenly"!) let the valve spring compression release and spin the cam it is going to be the upper (intake) cam on the drivers side. And IF your hand is on the sprocket when this happens, you just lost a pretty noticable layer of skin from you hand, and trust me, your neighbors will know it happened!

 

Just turn it back where it is supposed to go. The other 3 cams are pretty benign when it comes to rotation.

[DerFahrer]

I'm fairly sure the passenger side cam does not have any valve springs compressed, and the driver's side cam has valve springs compressed, but it's right at the top of the lobe, so you've got a little room to move it either way before the spring will try to start moving the cam. This is when all the timing marks line up.

 

In other words, if you have all the timing marks lined up, the cams shouldn't move anywhere when you take the timing belt off.

 

Just for extra safety though, remove the spark plugs. Then you won't have to worry about engine compression.

[Top]

I used a couple of the mini-bar clamps with the rubber pads. Position them horizontally right between the two sprockets and snug them up. This works to hold them for the timing belt change but to remove the sprockets you will have to take the covers off so you can hold the cams with a 1" wrench.