Hello all,
I had to do headgaskets on my vh41 (91 cima) and managed to not paint/mark the chain+sprocket alignments before pulling everything apart.
This wouldnt be a problem, since there are marker links and notches, right?
Well, the chain length between marker links differs by one tooth side-to-side. So I can put these on backwards, or just one, or a couple on backwards, and will not be able to figure out where I went wrong by just trying different orientations, as the problem compounds through ^4 chains. The engine is not intereference enough to cause valve+piston contact if a tooth or two out, so hand-cycling to check for contact/failure doesnt really help much.
Anybody have some insight for me? How do I figure out the correct orientation? all marker links are the same color.
I'm using the y33 service manual for reassembly.
thanks much
VH41de timing chain install, failed to mark alignment on teardown
-
manicgarage
- Posts: 3
- Joined: Mon Apr 10, 2017 8:04 pm
- Car: 1992 R32 skyline gtst sedan (heart of a Cima)
1999 Pathfinder
Re: VH41de timing chain install, failed to mark alignment on teardown
Hello, welcome aboard.
Even if you didn't mark the chain, the sprockets should have timing marks on them. Then each chain will have an off-color link (most OEM ones I have dealt with have been like this). You don't necessarily need to put it back to the condition you found it in, as most engine reassembly procedures assume you'll put the #1 engine at TDC and set timing from that point.
Assuming you don't have (m)any before pics, might you have the after ones in current state?
Even if you didn't mark the chain, the sprockets should have timing marks on them. Then each chain will have an off-color link (most OEM ones I have dealt with have been like this). You don't necessarily need to put it back to the condition you found it in, as most engine reassembly procedures assume you'll put the #1 engine at TDC and set timing from that point.
Assuming you don't have (m)any before pics, might you have the after ones in current state?
Re: VH41de timing chain install, failed to mark alignment on teardown
I read your post, drafted a reply, realized you already knew about the markers, but I still forgot to delete my paragraph.
I meant to just ask for the pictures. Also, are you starting at TDC?
I meant to just ask for the pictures. Also, are you starting at TDC?
-
manicgarage
- Posts: 3
- Joined: Mon Apr 10, 2017 8:04 pm
- Car: 1992 R32 skyline gtst sedan (heart of a Cima)
1999 Pathfinder
Re: VH41de timing chain install, failed to mark alignment on teardown
Pre-disassembly:
Current state:
I've assembled it as shown in the last shots and spun it by hand 100+ times (starting from/returning to TDC) and the cam positioning doesn't appear to wander, but I'm not certain it's starting correctly in the first place. Also all markers did not return to simultaneously lining up again in that rotation series.
Current state:
I've assembled it as shown in the last shots and spun it by hand 100+ times (starting from/returning to TDC) and the cam positioning doesn't appear to wander, but I'm not certain it's starting correctly in the first place. Also all markers did not return to simultaneously lining up again in that rotation series.
-
manicgarage
- Posts: 3
- Joined: Mon Apr 10, 2017 8:04 pm
- Car: 1992 R32 skyline gtst sedan (heart of a Cima)
1999 Pathfinder
Re: VH41de timing chain install, failed to mark alignment on teardown
I should mention that in the test setup above, I've set the long side of each chain toward the tensioners. maybe arbitrary, maybe not.
Re: VH41de timing chain install, failed to mark alignment on teardown
hmmmm... WWED - what would EdBwoy do:
I'd look at the pre-teardown pictures and get to counting links. Forget the colored links as those could be hanging out in the air between sprockets sometimes. For example for the long chains from the crankshaft, count from a certain mark on the crank sprocket to another mark on the receiving cam sprocket/ water pump sprocket. Move the colored links if you must, but I'd count those and make sure the current pics match the older images. Do the same for the secondary chains.
Yes, it sucks to count from pictures (smart move on taking the pre-dismantling ones btw) but I can find other corrective measures that suck more. Personally I hate scraping the RTV off.
You might find that some chains are the same size (number of links between the bronze ones, etc), but then that would make it a little easier for me. Do the colored links have the off-color on both sides so that you can actually install them backwards? If they're equivalent, then it doesn't matter. But if the gap is 9->13->19 links between color, then that should give you a good idea of which bank they go to or if they are reversed.
But you are right, in that the tensioner side will usually be longer as it's the last side to be installed. The other sides will be dang tight on the sprockets. And also true that the colored links don't go back to their original orientation until you spin it a 1,000 times, not just 100. Just kidding, I could probably tell you if I calculated the gearing, but you get the point.
If you please, get it back to TDC and remove the chains & reinstall them again. But I understand that this circles back to you knowing what links are supposed to be where.
... but that's the best way I can put to words what I have in my mind. I'll keep offering my help till you tell me to stop confusing you, haha. See if you had a VK45DE, I'd go to my garage and give you a tried and verified answer.
I'd look at the pre-teardown pictures and get to counting links. Forget the colored links as those could be hanging out in the air between sprockets sometimes. For example for the long chains from the crankshaft, count from a certain mark on the crank sprocket to another mark on the receiving cam sprocket/ water pump sprocket. Move the colored links if you must, but I'd count those and make sure the current pics match the older images. Do the same for the secondary chains.
Yes, it sucks to count from pictures (smart move on taking the pre-dismantling ones btw) but I can find other corrective measures that suck more. Personally I hate scraping the RTV off.
You might find that some chains are the same size (number of links between the bronze ones, etc), but then that would make it a little easier for me. Do the colored links have the off-color on both sides so that you can actually install them backwards? If they're equivalent, then it doesn't matter. But if the gap is 9->13->19 links between color, then that should give you a good idea of which bank they go to or if they are reversed.
But you are right, in that the tensioner side will usually be longer as it's the last side to be installed. The other sides will be dang tight on the sprockets. And also true that the colored links don't go back to their original orientation until you spin it a 1,000 times, not just 100. Just kidding, I could probably tell you if I calculated the gearing, but you get the point.
If you please, get it back to TDC and remove the chains & reinstall them again. But I understand that this circles back to you knowing what links are supposed to be where.
... but that's the best way I can put to words what I have in my mind. I'll keep offering my help till you tell me to stop confusing you, haha. See if you had a VK45DE, I'd go to my garage and give you a tried and verified answer.
-
Q451990
- Moderator
- Posts: 11030
- Joined: Tue Jul 23, 2002 8:21 am
- Car: 1990 Q45 - 118K, 2022 Toyota 4 Runner, 2004 Frontier M/T - 108K, 2012 Xterra (Mom's), 2023 Rogue (Inlaws)
- Location: Columbia, SC
- Contact:
Re: VH41de timing chain install, failed to mark alignment on teardown
Engine looks very clean. What caused the head gasket failure? That's pretty rare...