Is it absolutely necessary to hold cams in the cover?

Northern Chev · Post by **Northern Chev** » 03 Feb 2012, 09:07

2000 V70 XC SE 2.4 LPT

Is it absolutely necessary to hold the cams in the cam cover when removing said cover?
If you are careful can't you simply remove the cam cover and leave the cams laying on the head during removal?

The head and cover are being completely disassembled for rebuilding anyway so do I really have to keep them in the cover during removal?

Is it because valve spring pressures will be unevenly distributed across the shaft when removing the cover and may break the cam by pushing up in one spot? Or is it because the cams may roll off the head and get damaged?

I've seen forum pictures of people installing them without the special tools, couldn't you remove them the same way?

- ALSO, I can not seem to break the bolt that holds the exhaust gear and VVT unit to the exhaust cam loose. Any advice?

Post by **erikv11** » 03 Feb 2012, 09:38

On holding the cams: the pressure from the valve springs is uneven across the cams, due to the positions of the lobes. So the cams do not push straight up, they tend to slant, with the back ends higher. When this happens, there are slots in the head that can crack due to the guides in the cam torqueing on them.

It is OK to not hold the cams in the cover as you remove it, if you make CERTAIN the cams lift straight up. As you open the gap by unscrewing each bolt a half turn, each time you complete all the bolts take a moment to lift the rear and front of the cam to make it flush with the cover. Don't bang on them, use firm pressure, pulling up. If you are careful and go slowly, it will be fine. I have taken off several cam covers this way, never any damage. The trouble happens if you just spin off the bolts and lift the cover, the cams will be wedged in there and the head likely already cracked.

Same concept on reinstall. Attaching the cams to the cover is easier, I have done it both ways, but it is not required.

Northern Chev · Post by **Northern Chev** » 03 Feb 2012, 09:49

I'm also having trouble getting the VVT center bolt loose in this engine. Do I really have to remove the VVT unit and gear (together as one) from the exhaust cam BEFORE removing the cam cover?

Is there something INSIDE the cover that will catch on the VVT unit if I don't? Honestly I'd rather NOT remove the gears from the camshafts if I don't absolutely HAVE to. Or do they have you remove the gears so you can install the camshaft retaining tool to hold it in the head during removal? If that's the only reason then I'd rather NOT take the gears off. Any advice and opinions on this too are welcomed.

I'd rather not mess up the gear alignment on this VVT engine since the camshafts gears aren't "keyed" for alignment on the front snout of the cam.

Northern Chev · Post by **Northern Chev** » 03 Feb 2012, 13:06

UPDATE: Yes, in fact you do have to remove both gears including the exhaust gear with the VVT attached as the lip from the head and the cam cover protrude into the back-side of both gears preventing you from being able to raise the cover. The lip on the head catches on the inside of both gears.

I just tried it and you can't do it. But my VVT center bolt STILL will NOT come loose. Advice?

binglax09 · Post by **binglax09** » 03 Feb 2012, 17:55

You guys are smokin crack!!!

The cams won't break anything, it happens if you lift the cover to much on the tranny side.

Also you can leave VVT installed, just pull the cover while holding the cam in the cover with you hands. It will work out and then you can take VVT out afte the cover is off.. Easy peasy..

Post by **erikv11** » 03 Feb 2012, 21:32

Yes, it happens if you lift the cover too much on the tranny side, like I described. And if you do that, what breaks?
The head breaks (well, it cracks, like I described).

And, why does the head crack?
Because the cam cracks it.

binglax09 · Post by **binglax09** » 03 Feb 2012, 21:38

Not because the cams are not held down, it's because you are ripping the cams up with the head.

You just wiggle the top cover off without going to much of an angle on the tranny side. The cams themselves will not mess the head up from the lifter springs.

You stated that you need a cam holder so that they wouldnt spring up and mess the head up. They can float around on top without any issue just as long as you don't take them for a ride when tipping the top cover off.

Post by **erikv11** » 04 Feb 2012, 02:24

Exactly. The cam holder I am talking about doesn't hold the cams down, it holds them UP so they come up with the top cover. The home-made tool that Haynes describes etc. So the holder keeps them UP in the cover.

The valve springs do push up the back part of the cams, more than once I've had cams start to get stuck up at the front because of it, but "floated them up" and it was fine. That is why the angle opens up on the back (tranny) side.

We're saying the same thing, just you thought I was talking about holding the cams down but I'm not - the holder keeps them UP into the top cover. And you don't really need it.

Northern Chev · Post by **Northern Chev** » 04 Feb 2012, 23:33

Binglax you can NOT lift the cover with the VVT cam gear still on the car. There's a lip on both the cover AND the head that extend into the back of the cam gear and will NOT let you lift either the cover or the cover with the cams out. I am absoulutely sure on this now as there is NO amount of angling or sliding or anything that can be done like you describe on this VVT engine. The gear with the VVT on it HAS to come off.

If you lift the cam with the cover, then the lip on the head that matches the lip on the cover hits the bottom of the inside of the gear. If you lift the cover without the cam the top of the lip on the cover hits the inside of the top of the gear. The cover will not wiggle right left or back and forth to allow it to come off without removing the gears on THIS engine anyway.

My problem now (still) is that the bolt that holds the VVT to the cam will NOT loosen. It wouldn't loosen before and now it definetely won't loosen now that I have the cover bolts out and the cam moves around. This bolt refusing to come out is why we tried removing the cover and leaving the gears on. The VVT bolt won't come out.

ChrisD · Post by **ChrisD** » 19 Jan 2017, 10:28

Yes with a little nudging and pulling you can remove the cover with the cams in place as well as removing the cams from the head with the vvt units still on the cams. Although I don't know why you would want to. There is just enough clearance. Be careful and patient. Removing the cover ,...I mean if your removing the cover you should have the cam locking tool period. AND the VVT units should have already been removed WITH THE CAM LOCKING TOOL IN USE WELL BEFORE THE COVER IS EVEN CONTEMPLATED BEING REMOVED. The center bolts are 120 NM , they are tight and it is a real pain to take the VVT units off the free cams, when forced to do this I have to mount the camshaft in wood blocs. If you try to remove the center bolt by holding the outer belt pulley and the cam rotates, then the VVT unit is junk. Reinstalling the cover should only be done with the two valve cover tools as damage can be done to the head and cover by the camshaft if it moves during installation under tension.