about camshaft spacer and thrust plate

[dawnovsky]

Hi there,


I have been questioning myself a lot lately about the 6's camshaft spacer and thrust plate.
my unserstanding is as follow, please correct me if i am wrong.

- spacer is meant to create a 'clearance' between camshaft, cam sprocket and thrust plate in order to allow proper torquing of the sprocket without bending and wearing the thrust plate.

- thrust plate is meant to keep the camshaft from sliding out of the engine and only allow little free play. this end play is technically supposed to be related to the difference between spacer and thrust plate thickness and the extra room at the last bearing between cam and freeze plug on the rear of the engine.

-thrust plate have grooves to allow oil from the bearing to flow out on the camshaft spacer. it is not meant to oil the spacer but more probably to allow oil flow along the bearing and so allow fresh oil to lubricate the bearing.

-my thrust plate have grooves on both side. As i understand the design there is no need for grooves on sprocket side as it is not supposed to have much friction on that side (sprocket is not in contact with the thrust plate). so if there is grooves on both side (like the thrust plate i have (stock engine) it should mean thrust plate can be installed on side or the other. it might mean as well thrust plate has two lifes and can be reversible if the is to much wear on one side.
this two lifes design is not common in auto industry but this is something i have seen a few time on other mechanical designs.

-there is not much oil coming to the timing chain and sprockets (splash lubricated from the oil sump).

 

[bubba22349]

Hi there,


I have been questioning myself a lot lately about the 6's camshaft spacer and thrust plate.
my unserstanding is as follow, please correct me if i am wrong.

- spacer is meant to create a 'clearance' between camshaft, cam sprocket and thrust plate in order to allow proper torquing of the sprocket without bending and wearing the thrust plate.

1. Close: your right the spacer is to provide the correct clearance of the camshaft to thrust plate and cam gear the spacer makes it so it can all turn without excess friction!

- thrust plate is meant to keep the camshaft from sliding out of the engine and only allow little free play. this end play is technically supposed to be related to the difference between spacer and thrust plate thickness and the extra room at the last bearing between cam and freeze plug on the rear of the engine.

2. Yes!

-thrust plate have grooves to allow oil from the bearing to flow out on the camshaft spacer. it is not meant to oil the spacer but more probably to allow oil flow along the bearing and so allow fresh oil to lubricate the bearing.

3. Close: some oil is needed to lubricate the cam gear, front of cam nose and the thrust plate without oil it would burn up and gall these parts would then fail.

-my thrust plate have grooves on both side. As i understand the design there is no need for grooves on sprocket side as it is not supposed to have much friction on that side (sprocket is not in contact with the thrust plate). so if there is grooves on both side (like the thrust plate i have (stock engine) it should mean thrust plate can be installed on side or the other. it might mean as well thrust plate has two lifes and can be reversible if the is to much wear on one side.
this two lifes design is not common in auto industry but this is something i have seen a few time on other mechanical designs.

4. The cam gear is turning against the thrust plate it needs to have a little oil to protect those surfaces.

-there is not much oil coming to the timing chain and sprockets (splash lubricated from the oil sump).

5. Right it would only need a little oil to protect it.

Is the thrust plate nice and flat on cam side IE no grove worn into it? If not you should be good to go! Hope that helps you, good luck

 

[dawnovsky]

thanks for details,

my thrust plate was worn on the cam ide because i have he engine run with out the spacer i have forgot the collect from old cam. I have realize that after about 45 minutes of use and decide to reinstall the spacer.
thrust plate was indeed perfect on the sprocket side, so while looking for a new plate i decide to reinstall it reversly.
so the face curently facing the cam is the nice one. It have the 2 factory grooves for oiling.

 

[bubba22349]

If its not to bad you could use a surface plate grinder to get it flat again.

 

[dawnovsky]

is shape of the sprocket facing side really matters ??
IMO only cam facing side is important .

 

[drag-200stang]

Why take a chance? Yes, the cam is supposed to push forward because of the taper of the lobes. But why assume harmonics won't drive the cam shaft back with such little clearance between it. Make sure the plate is flat. No gauled materials sticking up on any surfaces. Both sides of plate, cam and back of sprocket. A wide, flat, fine file can be used carefully to knock large, high spots. Then the plate can be touched up with some very fine sandpaper and cleaned up with scotch-brite. Make sure you put the sandpaper on something absolutely flat like thick glass or a machined surface. You shouldn't have to remove any real material, just make sure there are no high spots and everything is smooth. If it doesn't clean up well, replace it.

 

[dawnovsky]

i would like to make things the good way. really.
If anyone of you know where to source new plate .... i ll not hesitate i buy a new one or even a nice used one .
Unfortunately, my plate is not in a good shape. reversing it is the "least worst" situation i could imagine for the moment.

will be probably able to get a another (used) plate from junkyard next time i ll have a few days in australia.
i had to get the car drivable to be relocated.

thanks