Timing chain guiedes

[diyanich]

Hi Guys,
A quick question about a crankshaft sprocket.
When the lower timing case was finally removed I noticed that the lower chain sprocket is somewhat scored/pitted,I don't know which term is more appropriate in this situation.




The groove isn't all that deep it's just like a polished aluminum,if I pass the nail over it,I feel a bit,but not that much.
It's the first circle closer to the end of the shaft.
I saw one DIY and a guy had the same thing pictured.
Should I be concerned and replace the sprocket or leave it alone?
Thanks.

[diyanich]

As you see from this picture,it's all nasty.
First of all,who worked on this engine before me(lower oil pan,upper oil pan,lower timing chain case,upper timing covers) and a year ago Valve Cover Gaskets.Everything was done with silicone and every single seam was leaking except the lower oil pan.
It was so difficult to remove it that I thought I would break the damn thing.
the rest of the seals was holding strong and it was quite an effort to get them separated,but yet all wet on the outside.Awkward.
But what was leaking the most were the Magnetic Solenoids' gaskets.

[xmac]

That looks very familiar. I did the same work a few months ago due to my massive leaks. I don't remember having that problem. It would be a pain to replace that sprocket since it drives the oil pump too. I would use some 1000 grit wet sandpaper and get rid of any bumps and just smooth it out as much as possible. Good luck!

[J.Belknap]

The oem solenoid gaskets aren't great, but they'll have to do.

The ring/polishing appears to have been caused by the front main seal. I would use acetone and a rag to clean it rather than risk sanding dust getting in places. Not saying sanding is incorrect. Just wouldn't be my method. Good luck with the rebuild.

[diyanich]

Thanks for your thoughts,guys.
I am gonna clean it well and dry fit to see if the main seal makes a good contact.
There was no oil seeping form the old one,so I hope that a new one will be enough without changing the sprocket.
Now,I have another question.Did any of you drop the front subframe to change the upper oil pan gasket?
In the DIY I see that there was a some sort of paper or alike material gasket,but I ordered and there's one steel gasket installed now.
Should I just clean it all well and use some gasket maker.It would be a nightmare too to try reaching all the perimeter without lowering the subframe that much.

[J.Belknap]

Wouldnt dry fit the front main. Just press it into the lower timing cover and reinstall cover when ready. Clean what you can see of the upper oil pan gasket carefully and reuse it. Recommend Wurth gasket maker (black rtv). Don't apply to the whole lower timing cover sealing surfaces. Just the bottom and the corners of the tops (where it meets the heads & block & upper cover corners).

Disclaimer: just an opinion on how to do some stuff

P.S. Check the threads on your crank hub. They will strip out with multiple uses.

[xmac]

Originally Posted by diyanich

Thanks for your thoughts,guys.
I am gonna clean it well and dry fit to see if the main seal makes a good contact.
There was no oil seeping form the old one,so I hope that a new one will be enough without changing the sprocket.
Now,I have another question.Did any of you drop the front subframe to change the upper oil pan gasket?
In the DIY I see that there was a some sort of paper or alike material gasket,but I ordered and there's one steel gasket installed now.
Should I just clean it all well and use some gasket maker.It would be a nightmare too to try reaching all the perimeter without lowering the subframe that much.

What I did was clean the metal gasket really well with brake cleaner until it was completely dry, slightly pulled up on it without creasing it and dabbed this aircraft gasket sealant. I then dabbed some on the botton cam cover. It takes a while for it to actually dry so have plenty of time to get the bottom cover on. The sealant is a VersaChem prime seal type 3 aviation gasket sealant. Worked great for me.

[diyanich]

Can anybody please explain what's the point of metal gaskets like an upper oil pan,lower timing case.
If I were to use the black rtv how should it be applied?I don't see any reason for a metal or whatever gasket if I had to put rtv on both sides of it.
Is oil gonna seep through if I only put the metal gaskets and a bit of rtv in the corners?
When I did my Valve Cover gaskets during Valley Pan DIY I followed the advises to put some silicone on the half moons corners.Gaskets didn't leak much,but rubber nut washers,not all,but some where seeping some oil.Was it because I haven't degreased them properly before reinstalling?
Please,let me know what to do,I don't really want to mess this one up and reseal everything in 10,000 kms.
Thanks

[diyanich]

Update:

I just got my Vanos seals done.Seals weren't difficult at all,but the pressing of the sprocket lip was a nightmare.Especially the first one.
The first sprocket was really difficult to insert into the lower press half and all the following complications.If I understand it correctly,all the sprockets meet certain limits,but given that that press is so stiff and the sprocket itself isn't a tin can alike,I had around 3 hours fight.My weapons were a torque wrench,which was completely useless because I met 105 ft. lb. after about a half turn of a bolt and I had about 5mm of thread to go yet.So my main tool was a 39" breaker bar with 1" head and an impact 27mm socket,both things were bought for a Jesus bolt.
So it took me at least 540º of rocking back and forth to get each leap pressed to the plastic with no gap left at all(used to be 0.9mm)
So now I want to mention about the Teflon ring and an O-ring.
The ones that I removed from the Vanos weren't that bad,but the O-ring was squared on the outer rim and Teflon ring was not a rigid as the one that came in Beisan System's kit.I managed not to damage any of those,so will need to return an extra Teflon ring I bought.
Over all experience during the process was good,Beisan's DIY is detailed,but the process is pretty intuitive itself especially when you remove the seals and you get where and how they are positioned inside.
I taped my struggles with that 39" breaker bar.Once my improvised vise base broke and I almost flipped my work bench,at some point I had to counter hold it with my foot at the surface level .Quite a circus I should say

[diyanich]

Another thing:

When I was placing the cam locks,I found out that the exhaust shaft on the 1-4 bank was retarded about 15-20 º ,so,whoever worked on that engine before me got it wrong.
I had to undo the torx to be able to jig the locking piece on.
Another thing is that it's quite difficult to do all the unscrewing just by myself,those torques are pretty high and it's tough to counter hold the shafts and so on.
But I was able to manage everything this far.
Also,before I was gonna drop the front subframe a touch,so it would give me a chance to change the upper oil pan gasket.But now I am thinking on passing on it.