960 Valve Cover Gasket

mxzxrider · Post by **mxzxrider** » 28 Nov 2011, 02:44

Can anyone point me in the right direction to find instructions on changing a valve cover gasket and spark plug seals on a 1997 960?

Post by **precopster** » 28 Nov 2011, 03:22

There is no gasket other than anaerobic sealer and 46 bolts holding down the cam caps directly.

This one is not a job for the first timer.

This is a whole day job beginning with removing the timing belt (be sure to mark all points with white paint before removing and scribe with a sharp point exactly where the six cam gear bolts are sitting)

Mark all your coil packs with their cylinder number and mark the loom wires as well.

The cam sensor will need to removed and earth wires on the cam cap also. Both cams will then be removed and both upper & lower surfaces will require a couple of hours of meticulous cleaning. All 46 bolts will require wire brushing and 46 threads will need to be blown out and checked for wear.

I had considerable difficulty in breaking my cam cap seal with the parting lugs provided in the casting so I actually hit the cam pulleys with a soft mallet upwards until it finally gave way. Be sure that all 46 threads are in good condition with no sealant in the threads. You may want to purchase a M7 X 1.0mm thread chaser to help clean the threads.

When retorquing the 46 bolts you may want to use a rear cam holder kit which you can buy from eBay and wire the front cams to the top cover. Another method I've been using lately is to use a battery drill on the lowest torque setting and working my way from the centre torque each bolt and go back around until it is fully down (this takes about ten minutes and patience is required as you don't want to use any one particular bolt working against all the valve springs as the thread will strip)

As far as rear cam seals are concerned this is the best time to replace them (and fronts too) and you will also need a rear cam seal driver as access to them is non-existent. I can upload a pic of the rear cam seal driver if you need it

By the time you scrape all the crud off the cylinder head you'll want to drain your oil and change it as much of it will be caught in the oil galleys. A bottle of Kerosene or similar to help clear the oil galleries is very useful

mxzxrider · Post by **mxzxrider** » 28 Nov 2011, 13:08

I'm pretty comfortable around an engine and have performed a timing belt kit change on the 960 and my daughters S40.
I understand this is not a typical valve cover and that it holds the cams. Can you tell me why the cams have to be "locked" or clamped to the cover when I take it off and put it on? Why not remove the cover and leave the cams in place or remove them after the cover is removed and then just set them back in position when I put the cover back on?
Also, I want to replace all cam seals when I do this, correct? 2 fronts and 2 rears, correct? Anything else I want to do while I'm in there? I read something about a rear cam plug?

Post by **precopster** » 28 Nov 2011, 13:45

The cam plug is on the inlet side and can be re-used. The last time I re-assembled my engine when I did the gasket change I forgot to put the inlet side rear seal in, but I did put the plug in; hasn't leaked a drop since

You can do as you said, but the hydraulic tappets push the cam upwards and nothing lays flat so it's a little awkward to do because the cams won't be located in their journals until it is all the way down. If the cams are clamped to the top cover you decrease the risk of damaging the cam journals as you torque it down.

The rear cam holders you see on eBay hold it at the rear and also stop it rotating but I made my own from flooring wood with an expansion slot where I placed metal tangs in the slots to stop the cams dropping down.

You may notice that all my bolts are shiny silver zinc because I actually threaded them all out to M8 as I had too many stripped threads. The whole job took 2 days and three months later the head was damaged by the accessory belt wrapping itself around the crank!!

It's a pretty stress filled time getting it down in the 10 minutes you have until the sealant cures so you want everything to be right. If I could afford the tools on eBay I would have them hands down; they would make the job very easy.

mxzxrider · Post by **mxzxrider** » 29 Nov 2011, 02:50

Precopster, thanks for the info. Very helpful. Sounds like the trickiest part will be holding the cams to the cover.
I'm wondering if anyone has the tool and would be willing to rent it out? I rebuilt the shocks on my motorcycle and the guys on the forum I was involved in would pass around a special tool required to disassemble the forks. Worked out really well.
In summary, I'm going to:
1) remove timing belt taking all necessary pre-cautions associated with this (marks are lined up, etc..)
2) remove cam sensor, coil packs, move all wires out of the way and anything else that is in the way on top of the cover.
3) Clamp the cams to the cover
4) Loosen all bolts a little at a time. I've read do not remove bolts until the cover has been loosened.
5) Gently pry/tap cover until the chemical bond has been broken then remove all the bolts and remove the cover. I guess when the cover is removed, all cam seals just fallout at this point, correct?
6) Clean all surfaces.
7) Apply the chemical sealant to the cover.

Install cover. I've found another write up with torque specs and tightening instructions.
9) Install seals.
10) Install timing belt.
Please comment on anything that doesn't look right.
Thanks again!

Post by **precopster** » 29 Nov 2011, 03:24

You don't need to clamp the cams to the cover when removing, however it's most important when placing it back on.

The cam seals won't fall out, you'll need to pull them off the cams. you usually need to pick the spark plug seals out of the head with a jewel screwdriver or small pick tool.

Torque specs are 7Nm for the 46 bolts.

Both cams have a slot in the rear. If you lose the positions of the cams this pic may help. At timing mark on the crank (which has pistons 3 & 4 around 3/4" from their top travel you need to have both slots at a horizontal angle.

Be very careful with putting the cam sensor rotating bracket back in place as it has a dowel that needs to fall back into one of those cam slots. GOOD LUCK, keep us posted of how you're going.

mxzxrider · Post by **mxzxrider** » 09 Dec 2011, 14:19

Hey precopster,
well,I finally tackled the project today. I have the cam cover off. I was expecting the cam shafts to be loose after I revoved the cover, but they are sitting in there pretty tight. I'm wondering if I can just clean everything off, apply the gasket, replace the o-rings and put it back together without pulling the cam shafts up?

Post by **Choguy03** » 09 Dec 2011, 14:31

Strange...They should be loose. Nothing holds them in once you have the valve cover off. I would actually want to remove them to check the condition of the lifters and give them a good clean.

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Post by **precopster** » 09 Dec 2011, 16:04

Very strange, the strength of the 24 valve springs acting against the lifters is quite strong and should dislodge the cams. As Choguy03 said I would want to check them but while they are down it makes putting everything back together very easy without needing cam locks at the rear .

Cleaning around them will be very difficult as you want to get the surfaces pretty spotless.

Good luck. Can you take a photo and post it?

Post by **jimmy57** » 09 Dec 2011, 18:19

The cam can bind up on the thrust flange at front. The cams will be up at rear but stuck up front.
I see a piece of the thrust face on the head broken off on the right side in second photo posted. Look just behind where the seal would go at front of head. That is where it hangs and can break off a piece. The missing piece is of no consequence.