So for all of you considering the friction
gear spring replacement, here are some photos of what we're talking
about and some comments on what to watch out for.
First off is the part itself....

Next....all the parts of the rear camshaft friction spring assembly. Notice the shiny areas on
the inside of the spring washer and the outer ring of the nut. These areas show
much greater wear than the contact points of the spring washer and friction gear....meaning it probably spent more time
spinning on the nut then on the gear like it's
supposed to....which is why it was redesigned...which you'll see later below.

Now where the fun begins. You can take the FGS apart
without removing the timing belt. HOWEVER, this poses several problems. First,
the end camshaft thrust journal that holds both cams down can not be fully
removed because it's too large to pass by the timing sprocket and gear on the belt driven cam.
This is the part I am lifting to it's maximum here.....

Why a problem? 3 Reasons.
First, you have to seal the mating surfaces of the thrust
bearing and cylinder head with silicone. There's about enough room for a small
pinky finger between them at max. Remember, you have to clean out the old first
and can't get any of the new silicone on the cam itself (yeah...sure Houdini).
Second, you're not supposed to clamp the cam seal between
the two halfs...it should be pressed in once they're assembled (which requires
removal of the timing belt and sprockets). If you end up going the route of not
removing the timing belt...put a thin coat of silicone on the cam seal to
prevent it from being snagged and pinched when assembling. Wave a dead chicken
over it as well :razz:
Third....there are end plugs in the cams that don't protrude....same
problem as above....pressed in after assembly usually and no room to press them
in once you put the pieces together. Once again, clean and silicone or replace
and silicone.
Here is another shot of the journals and thrust bearing.
The cam end plug seals the end of the cam on the right. Keep in mind...you need
to apply sealant between these two aluminum pieces and it only lifts maybe
1/2" at most..........

Now the serious fun and the begins.
You will notice that your replacement FGS has two little
tangs where it's supposed to slip over the collar on the nut. Why? To keep the
FGS sliding on the larger area of the spocket instead of just spinning on the nut
side. Looks like this.....

My first thoughts .....
How will this fit on the nut? Well, there is a newly
designed nut with notches in it. One problem though......it's special order at
Ford and Mazda (at least around here). Not the time to find this when the
engine is apart
What now? Die grinder. Used a dial indicator to find the
center of the sides of the nut and cut a "U" shaped notch in two
places....looks like this....

Fit just swell.
Other outstanding issues....
Hope you have a serious tool collection or a trusting
mechanic friend. The nut and flats on the camshaft are bigger than 32mm and on
really tight. I have nothing over 1-1/4" or 32mm. Had to use a plumbing
wrench and towel.
Make SURE you have the Friction Gear...this
thing.....

...and the cam gear teeth
lined up with each other at the marking point for aligning the two cams
together. You will not be able to install the cam if the teeth are misaligned
and it's just about impossible to turn the FG with the new spring on. Look for
the painted marks and punched circle in the cams to see the alignment point.
Good luck holding the FG from turning while tightening the nut....you almost
have to anticipate the amount it will move and misalign it that much before
tightening.
Lastly, remember to rotate the engine so the cams are not
under any spring pressure from the valve springs. It should be off all HLA's
and you should be able to spin the HLA's in their holes...if not, it's still
under pressure. When you loosen the bearings, you'll chance bending them this
way.
That's all I can think of right now.