installing timing belt problem

[A. Jay]

when I was removing the head, it looked like the cam gear on the exhaust cam is a tooth off from matching the factory mark on the gear to the factory mark on the top of the plate that's behind the gear when the first piston is at TDC. The gear needs to be turned counter clockwise to match. I read the haynes manual and it says to put it back together how you found it, but the timing belt was changed by the previous owner, so I think there may have been a mistake. What do you guys think I should do when I put it back together?

 

[sogi99]

just follow the tsrm unless the cams you have are not stock. The dowell pin on the cam gear should be in the middle for both intake and exhaust. I think our motors are non interfering so you will not bend any valves if timing is wrong.

 

[Zumtizzle]

just match up all the teeth.

then take off the CPS and reset that as well because the EX cam drives the cps.

But install the CPS as this for more adjustablity.

Just as the cps gears begin to touch the cam gears, this is how the "pole piece" and the G1 pickup line up with each other.

After the CPS is fully inserted against the head, the "pole piece" and the G1 pickup are not aligned perfectly. The "pole piece" is just a little past the G1 pickup in the clock wise direction.

Here is a better picture of the correct CPS alignment

 

[grimreaper]

^ cant get any better then those pics right there!

here are a few from when i had to retime the cams from other work... Make sure to use a chopstick or something in the #1 sparkplug hole to verify TDC and that the harmonic dampener is at 0...

 

[rayall01]

It baffles me that so many people have a hard time with timing a 7M, cause they're about the easiest engine to time I have ever worked on. Try timing a subaru sometime. Now that's a pain in the ass.

 

[paradox616]

buick v6 is easier, just match the dots on the chain

i bet they're trying to do it with a tight tensioner, either that or your backing plate for the head isnt where its ment to be

 

[Hmong_1G]

Stupid question but would the oil pump also needed to be aligned? What also fascinates me is that the oil pump shaft gear is kinda huge and unmarked. Wouldn't the theory of using a smaller gear to have higher oil psi play here ( if oil pump gear doesn't haven't to be align and of course using a smaller timing belt). Just a theory.

 

[A. Jay]

just follow the tsrm unless the cams you have are not stock. The dowell pin on the cam gear should be in the middle for both intake and exhaust. I think our motors are non interfering so you will not bend any valves if timing is wrong.

they're the stock cams, and I believe the cuts that are made on the surface of the pistons are for that purpose. Well, at least I know it is on some cars.

^ cant get any better then those pics right there!

here are a few from when i had to retime the cams from other work... Make sure to use a chopstick or something in the #1 sparkplug hole to verify TDC and that the harmonic dampener is at 0...

I agree, and I'll make sure of that.

It baffles me that so many people have a hard time with timing a 7M, cause they're about the easiest engine to time I have ever worked on. Try timing a subaru sometime. Now that's a pain in the ass.

This my second car and supra ever, and I didn't have this problem on the first one.

buick v6 is easier, just match the dots on the chain

i bet they're trying to do it with a tight tensioner, either that or your backing plate for the head isnt where its ment to be

I'll check the backplate when I put it back together, just to make sure.

Stupid question but would the oil pump also needed to be aligned? What also fascinates me is that the oil pump shaft gear is kinda huge and unmarked. Wouldn't the theory of using a smaller gear to have higher oil psi play here ( if oil pump gear doesn't haven't to be align and of course using a smaller timing belt). Just a theory.

I wouldn't see why the oil pump would need to be aligned, there's no position sensor so nobody (the electronics) care where it is. Don't know what to tell you about the higher psi theory though.

Thanks for all the info guys!

 

[rayall01]

livinasask8er, my comment wasn't specifically about you. It just seems like, I see so many threads about timing issues. It truly is one of the easiest things you can do on a 7M.

 

[A. Jay]

livinasask8er, my comment wasn't specifically about you. It just seems like, I see so many threads about timing issues. It truly is one of the easiest things you can do on a 7M.

Oh, it's cool then. I've never done any cam timing before, but I get the idea of what's happening. Now spark timing is easy, even I can do it lol.

 

[paradox616]

livinasask8er, this is my method and works everytime

1) remove cam gears, align backing plate as centred as you can get it (use the bolt holes as a rough guide, its got a fair bit of movement in it)

2) install gears (match perfectly backing plate)

3) loosen tensioner bolt (but not too loose!)

4) pull the belt tight so that its seated on the oil pump gear/crank drive gear correctly, while keeping the belt tensioned match it up to the grooves on the intake cam shaft, and proceed untill you can get close to the exhaust gear, at this point you need to pull the tensioner back with your hand and while still keeping tension on the belt so it dosnt loose its place on the intake cam gear, gently slide it onto the exhaust gear. if it dosnt match up perfectly adjust slightly and try again.

i bet this makes no sense to you.. but the key is line it all up first then try to fit, you wont ever get a perfect match to the backing plate but you'll get close.

FYI its also common for belts to skip a tooth.

 

[IJ.]

36ft/lbs on the tensioner not a pound more...