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bw77

Tb Change And Need For Cam Locking Tool

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I have a 99 S70GLT with 98K miles, and I am thinking about changing the timing belt myself. I have looked at the Bay13 tutorials for both the 850 and the S40 timing belt changes. On the S40 belt change he uses a cam locking tool, but on the 850 belt change he does not. I assume this is because the S40 has VVT on the exhaust cam. I believe my car has VVT, also, but I have not looked yet.

My question is this - why is it so important to lock the cams on a VVT engine, yet not on the non-VVT engine?

Thanks.

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It's important because most people don't know how to properly reset a VVT hub.

If you do, then you don't need to lock it.... although with the S40/V40 you don't need to lock ti because its a solid VVT unit, therefore the vvt hub doesn't move seperately from the camshaft.

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A cam locking tool isn't necessary for just a belt change. You just need to pay attention to what you are doing. My memory fails in regards to your car having a spring loaded hub or not. Ultimately, the CVVT hub needs to be in the place it was before you removed the belt, or it's end position. I suggest before removing the old belt you make marks on the timing cover with some white out and then add another set of alignment marks on the back side of the cam gears and the head. This way you can make sure the engine is in time without taking the timing cover on and off while you are installing the new belt.

If the CVVT hub moves on you while you are changing the belt, don't freak out, it can easily be put back to it's end position, simply align the marks you made on the back of the cam gear to the mark on the head.

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i have done 3 of these 99+ TB'S all i did was turn the car until the two top marks are at 12 noon factoring in the engine is tilted to the rear. its a 32mm crank socket.

1: take the spark plug cover off

2: take the tb cover off

3: there is another cover down at the bottom near the crank pully IIRC

4: slide the tb belt off

5: take the idler pulley off

6: take the tensioner off

7: take off the water pump

you'll want to temove the two pulleys off before removing the pump, this way the pump can come out easier.

of course you drained the coolant before you started all this. also since you are doing the coolant drain/flush you'll probably want to spend the $10 bucks and buy a t-stat too since the coolant will be drained out.

replace back in reverse order.

should take about 2-3hrs for your first one. it's not a big deal to do. the 98 and older cars, have this hydraulic tensioner thats a bitch to eff with.IMHO

if you get a p0014 code after the tb change, timing is off by one or two teeth. no biggie, just realign the crank with the mark down at the bottom, then line up the two cam gears to the mark on the head. after you do your first one, you'll think its easy like me! :D only thing i think is a PITA nowadays, it swapping out a AWD tranny. :(

look at the money you will be saving if you switched to gieco, thats how i look at it if i did it myself! :P

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The cams on the 850 don't move(never on me anyway) when removing the t-belt and I personally don't lock them. The cams on the P2 cars do seem to move and I do lock them. Not for the fear of the CVVT but I find the job goes much quicker if they are locked. Every darn P2 car I ever did(which is a lot) w/o locking the cams the exhaust cam always shifts and that just irritates me personally so I lock them. Time is money and I find it easier to lock them then to move it back up on time. The manual tensioned cars the belt is tighter to install as well where the 850 you have plenty of slack on the tensioner/waterpump side.

I personally would recommend locking them.

;)

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The cams on the 850 don't move(never on me anyway) when removing the t-belt and I personally don't lock them. The cams on the P2 cars do seem to move and I do lock them. Not for the fear of the CVVT but I find the job goes much quicker if they are locked. Every darn P2 car I ever did(which is a lot) w/o locking the cams the exhaust cam always shifts and that just irritates me personally so I lock them. Time is money and I find it easier to lock them then to move it back up on time. The manual tensioned cars the belt is tighter to install as well where the 850 you have plenty of slack on the tensioner/waterpump side.

I personally would recommend locking them.

;)

i would lock it too if i did them all the time. you sure are correct if it was locked then it will be alot easier

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The cams on the 850 don't move(never on me anyway) when removing the t-belt and I personally don't lock them. The cams on the P2 cars do seem to move and I do lock them. Not for the fear of the CVVT but I find the job goes much quicker if they are locked. Every darn P2 car I ever did(which is a lot) w/o locking the cams the exhaust cam always shifts and that just irritates me personally so I lock them. Time is money and I find it easier to lock them then to move it back up on time. The manual tensioned cars the belt is tighter to install as well where the 850 you have plenty of slack on the tensioner/waterpump side.

I personally would recommend locking them.

;)

I am curious as the what tool you use to lock the CVVT cams. I have test fitted a few cam lock tools on the CVVT (Snap-on and Matco) cars and they all interfere with the CVVT hub.

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You don't need to lock the camshafts. If your VVT unit happens to move, always remember that the VVT unit has to be fully clockwise.... (If you grab your vvt unit with no belt, you'll notice you can move the hub counter clockwise about 3-4 teeth WITHOUT moving the actual camshaft). That being understood, if the hub moves back, just move it forward to TDC, if the camshaft moves, you'll have to move the hub and cam back 4-5 teeth then move it clockwise until your at TDC and it's set.

But both the vvt hub and the cam moving rarely happens, but, does happen.

Just take a peice of thick metal (a flat file or something), measure the distance between both cam gears (upper part a bit and lower part a bit) and cut

the file so it fits inbetween x 2. Then turn the crank so the metal peices "lock" the cams together, then slip off your belt and slip on the new one. (poor mans way of doing it but if you need a quick locking tool that will cost you less that $5 there it is)

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You don't need to lock the camshafts. If your VVT unit happens to move, always remember that the VVT unit has to be fully clockwise....

Thanks for all the advice. And thanks to PsychoWagon for the explanation about how the VVT unit moves. That would explain why you're supposed to turn the crank 1/4 turn past the timing marks, then back up 1/4 turn. That would put the VVT unit fully clockwise, right?

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aslong as the VVT unit can't move clockwise any further without turning the actual camshaft, the VVT is in the correct position.

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I am curious as the what tool you use to lock the CVVT cams. I have test fitted a few cam lock tools on the CVVT (Snap-on and Matco) cars and they all interfere with the CVVT hub.

It's a Blue Point ;)

I modified it where needed

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