No Timing Tools
I know you posted this a few weeks ago. But your probably still working on it. Lol.
If you have finished. This is incase you get another or for anyone else.
WARNING: I am not a mechanic. If you stuff this up it's your own fault. It is not the correct way to do this job and inaccurate cam timing is possible.
This is an interference engine be careful.
READ EVERYTHING BEFORE STARTING
First thing: Understand how the timing components are connected and how they work.The crank revolves twice for every one revolution of the cam. All timing gears are held by bolt pressure only. Except the crank gear. Undo the jackshaft sprocket retaining bolt and both cams rotate under valve spring pressure. Undo cam gear retaining bolt and that cam will rotate for same reason. This all results in loss of timing. Timing marks do not matter. The cam position to the crank (TDC) is critical. Chains and gears are not.
Second thing: You can drop the transmission to do the rear cassette. The cassette drops in from the top of the head with the chain and jackshaft sprocket on. It may require a bit of fiddling/wiggling around but it does drop down. Put in the cassette retaining bolt (the one with the torx head ) and tension the jackshaft bolt to specs.(you will work out how to achieve this further down) Put in new jackshaft plug. Trans can now go back on.
Note procedure is the same as engine out.
Some people skip the rear if it is not broken and pray. The front is usually the problem and all updated parts should be fitted. This can be done engine in.
Ok. Engine in or engine out your choice. Start procedure here.
Ensure #1 cylinder is at TDC
Ill skip to timing and valve covers off.
Don't unbolt anything internal yet. Check TDC #1. Check cams are timed correctly or very close.(read further down) Loosen cam bearing caps lightly and in sequence. Remove two cam bearing caps. Cut a piece of plastic coke bottle into 2 small strips, shorter than the distance the bearing caps cover. Bolt the bearing caps down with the plastic between the caps and the cam. Tighten all caps in sequence. Cam is now locked. If not, tighten the caps with the plastic under them a little at a time till it is. Do same for other cam. Unless you get carried away the caps will not break (do not let this happen) the plastic has a lot of give.
It is now safe to remove retaining bolts and all other components. Keep checking for cam movement just to be safe. I removed and torqued all bolts with this method as well as using opposite torque on the cams and wedged a bar through one of the holes in the jackshaft sprocket for added safety. Ensure all parts and chains are fitted and cams are timed. Before torquing up bolts you need to stop the front and rear cassette from moving or timing will be incorrect. I used a piece of wood that fitted between the head space near the screw in external tensioner and the top of the cassette. After all bolts are tightened. You can remove plastic strips. Start reassembly.
How to time cams:
If cam timing is out slightly due to broken cassette lengthening the chain travel or old chain was stretched.With the cam gear retaining bolt loose. Loosen the cam bearing caps with the plastic strips under them, very slightly until the cam can be moved with a shifter or pipe wrench but still needing some force. Remember to tighten them back up for torquing up cam gear bolts and others.
How to align cams:
There are a couple of ways to line up the cams. Use them all for better accuracy.
Cam lobes should face up on #1 and down on #5.
There is a nub that trips the cam sensor on one of the cams this should be facing straight up. There is a flat planed surface next to this, it is also on the other cam at the other end. This surface should be parallel to the head surface and on the same gradient.
There are cut out slots on the ends of each cam. The cut out is offset. Have the smaller part of the cut out facing down. This is hard to see on one of the cams due to it being close to the firewall. Find a rod that will fit nicely into the cutout with enough protrusion on either side so as to be able to measure the distance from the head surface.Make sure these are equal. If they are cams are correctly aligned.
Last edited by DefusedExploder; 05-19-2010 at 08:41 AM.
Reason: Warning added