Pulled the Mess that was my Timing Chain....

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Dodge72

Dodge72

Odd one out
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So I finally managed to get to the timing chain in my limited time to work on my Dart, and from what I saw was pretty bad. First off, when I got the cover off, a good amount of coolant began to pour right out from the timing cover. It happened when I loosened/pulled the bolt nearest to the water pump; normal or no?

When I got the cover off, I noticed the horrible slack on the chain. The teeth on the cam sprocket were curved and rounded off. But the bolt that held the sprocket to the cam was loose; as if someone didn't even bother tightening it. Lining the gears off and taking them off, I noticed the wear/gunk on the cam sprocket, and there was a pin hole (?) underneath that appeared void of these little pins that were around the timing chain area. I also circled something else near the cam sprocket; possible key notches for the sprocket?

The general fear is that there was a pin that was supposed to hold the cam sprocket down, but because of that and the loosened bolt, it wobbled all over the place and damaged itself and potentially caused even greater damage inside the block. Another opinion said there may have never been a pin there, and the loosened bolt caused the timing chain and sprockets to wear faster.

My car hasn't been running for two weeks now, and it's stuck in my school's auto shop, so I have limited time to work on it every day. I'm hoping to get some advice to those more experienced with doing the timing chain. Greatly appreciated.


Timing chain area with cam sprocket off (the crank sprocket is on still, I know). Circled around the cam area, with the odd mark and the suspected pinhole:
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Below is the closeup of the cam area:

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Here is the cam gear itself; you can kind of see the worn teeth. Weirdly enough, this thing doesn't look old at all either.

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And crappy photo before I got the timing chain off:

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Yes there should be an index pin in the cam. The hole looks egg shaped to me. All the black "gunk" around that hole in the cam and on the cam gear is a combination of metal particles and oil from the metal fretting and grinding. Now mind you I'm not an expert on the slant but it also looks to me like the cam gear has cut into the block where it rides but I may be incorrect on that. The washer looking thing I have no clue. As far as the wear on the gear teeth that is probably the result of the camshaft walking in and out of the block causing a side loading of the chain to the gear teeth. My hunch is the cut around the cam on the front of the block isn't normal and the metal from the pin working acted like valve grinding compound. I would personally pull the oil filter and cut it apart to see how much metal is in there. Personally the prognosis isn't good in my opinion. I think you've got a lot of metal floating around in there. Again this is what I see, someone else will be along that's more familiar with the slant.
 
Two weeks back I changed the oil (when I initially brought the car into the shop and it was running; mind you, it stopped running all of a sudden overnight), and I did check it for 'sparkles' or the metal flakes. No such thing; The oil, albeit extremely dirty, didn't have any sorts of particles or sparkling that indicated metal. Could have larger particles been caught in the filter?
 
Large pieces would be caught by the strainer on the pickup. Anything small enough to pass the strainer would go thru the oil pump then the filter. Have you drained the oil after pulling the timing cover? The problem with fine metal particles is they travel all over. Like I said the face of the block where the cam gear rides just doesn't look right to me. I just am not that intimate with the slant. As far as it quitting, whatever grip the cam gear had to cam probably let go and allowed the gear to freewheel without turning the cam. You could try sticking a magnet down into the oil pan and see what you pull out. I hate seeing people run into issues. Hang in there.
 
Time for a new cam and lifters at the very least.
 
Coolant draining from the top left hole of the timing cover is normal; that hole goes into the water jacket. The circular machined circular mark on the right side of the cam area is OK. I forget what it is for but have seen it; it is for an oil relief or oil spreading slot around the sprocket thrust area.

The missing dowel pin in the cam is there for alignment (and is the ONLY alignment device for the sprocket on the cam) and the holes in the cam and sprocket are definitely egged out. I would not worry about any other damage inside the block. The engine stopped when the pin fell out and the valve timing got all out of whack.

If you want to try to salvage the cam with some careful work, you can slowly drill out the hole in the camshaft and put in a slightly larger pin and do the same on a new cam sprocket. Drill slowly and carefully. In fast, I would use a small reamer to get the lead in edge of the cam hole round and then drill slowly and with light pressure from there.

The pin is probably in the oil pan, but the screen should keep it from being sucked up. You might be able to slide a magnet slowly along the underside of the pan, pick it up, and drag it to the drain hole.

The cam sprocket is not the stock one; it is a replacement Cloyes. Someone did not properly torque and secure the cam bolt. This needs to be torqued to 45-50 ft lbs, not the FSM 35 ft lbs. AND you need to apply Locktite to the cam bolt too. This is a common issue.

Yes, the cam has ridden on block a bit but that is the normal thrust surface for the cam sprocket. It looks like the cam sprocket was not pulled down tight to the cam face on the dowel pin side and the cam sprocket was at a slight angle. Once again, improper torquing of the cam bolt is the culprit, along with just probably pushing the cam sprocket in place a bit crooked to start with. The original dowel pin will be a tight fit in the Cloyes replacement sprocket hole, so it is easy for folks to get the sprocket cocked if they are not familiar with this.

If you pull the cam to replace it or to rework the dowel hole, then the lifters pull up through the head. The lifters can get a varnish ring around the lower end that keeps the lifters from pulling up easily sometimes. You need a very strong magnet and perhaps some surgical locking forceps to grab the upper edge of the lifters to pull them out, and some patience. Some times a bit of carb cleaner or gum cutter around the lifter bore will help cut the varnish.
 
I have not drained the oil after pulling the timing, but I'll check for metal particles when I manage to get back into the shop. Besides, from the times from when it /did/ run from when I changed the oil was a matter of just a day. Driving it was just to get it onto another lift.

If the pin WAS there, where the hell did it go? And is there any chance of getting a new/replacement one? The shop teacher was concerned that the wobbling of the came sprocket may have rounded out the cam itself, but it doesn't look obviously rounded....I wouldn't know though, this is my first time doing this.


EDIT: Saw your post after I posted. Thanks for the insight, I'll be looking through the oil pan for that damned pin. To possibly drill out that new hole, are you saying that I need to pull the cam in order to do that, or is it possible to do so without pulling it out? As for the 'new' larger pin, does it have to be some sort of specific metal? I heard it needs to be something like forged steel or something extremely strong in order to prevent it from shearing off.
 
OK and I revised my post a couple of times so you might like to re-read it. Personally, I would pull the cam and work carefully. The drilling needs to be done with precision, so doing it with a hand drill in the car is problematic. I would do that in an emergency only.

I really don't know the pin hardness you need but I suspect the equivalent to a grade 5 bolt would do it. The cam bolt ought to do most of the work to hold things still. I have put in hot rodder type cam offset bushings for cam timing in my /6 and they are not particularly hard steel. You can find pin stock in many places and sizes. The trick will be to got just big enough to fit the widest part of the hole but not go too big and break out of the side of the cam; that would not be usable as it would get into the cam bearing. After more thought, I might use a Dremel tool to initially grind the hole inwards towards the sprocket bolt hole.

The pin has probably 'worried' the dowel hole in the direction to retard the cam. So, if you redrill the existing hole to put in a slightly larger dowel, it will likely center in a cam-retarded position. These engines seem fairly sensitive to cam retard and it might be doggy. So that speaks to perhaps another cam or putting in some cam timing bushings to get the cam timing corrected.
 
And there is another way to fix this.... Some serious /6 guys will drill and tap 3 small holes in the cam sprocket and cam face and use those instead of the main bolt. If you do this, then the cam sprocket hole will line up on the right edge of the cam's dowel hole as shown in your pix to be properly timed.
 
Thank you so much for the options and the explanation of what happened. I feel like I can fix this and fix it good.


Out of the three options, is it worth pulling the cam? I just got this car three months ago and haven't tore into the engine much at all, so I really don't know the extent of the damage, so to speak. As what I've seen of just completely sloppy work (wiring mixed up, wrong torque on things, ect.), I wouldn't be entirely opposed to pulling it off and starting fresh. Then again, I'm not even in my own house, and it's sitting day after day in the school's shop and to get it running would be a giant relief.
 
If I had it that far down, no way would I leave that cam in there. But, different people do things different ways. Good luck.
 
I am with RRR on this one; it is best to pull the cam. If you drill in place, the metal chips are going to be difficult to keep out of the engine. And, some precision is needed in the drilling, and the cam is going to walk back into the engine on you as you drill. Not doing this part well will put you right back where you are.

Besides, you have done most of the hard part of getting to the cam already: the front timing cover. The most rest is easy, and you need to pull the valve cover anyway on car that has not had good maintenance to adjust the valves and inspect up top.

When you pull the lifters, make sure that you keep them in EXACT order, front to back. Get a box with compartments (an egg carton is good) and number them 1 to 12. Mixing existing lifters is pretty much a guarantee of some wiped out cam lobes. I also keep the pushrods in order too.

I almost forgot that you have to pull the oil pump out part way and the distributor. The distributor is easy; the oil pump can take some judicious prying to pop the pump and gasket loose. And getting it free of the block can be a hassle; read Pishta's recent work to R&R the oil pump.

If you drill and tap 3 smaller bolt holes in the cam sprocket and cam face, try to get at least 1/4" grade 8 bolts in there; you might need allen head bolts to fit well. And use flat and lock washers on each; SAE flat washers are narrower and may fit better in the cam sprocket's front recess. Use Locktite on the bolt(s) regardless of which way you go; clean out all the oil before applying Locktite.
 
RustyRatRod said:
If I had it that far down, no way would I leave that cam in there. But, different people do things different ways. Good luck.
Click to expand...
Are you thinking that something else might be amiss with the cam? Or just the crapped up dowel hole? I don't want to miss any judicious advice here. I suspect the OP is on a budget, so that is the reason to offer some re-use options.
 
The right way is the long way. You should take it down to do it right.

While as is, have you tried to fit a new dowel? Pictures do show damage to the hole. Pretty hard to tell extent of damage from them.

I wouldn't worry about the "C" cut in the face. IMO just to help lubricate between the block face and gear.
 

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The dowel hole is wallowed out. Does he have a way to drill perfectly straight? To me, it just makes too much sense not to re cam it now. It's damaged, it has just as many miles as that floppy chain and he is THERE.

Plus, where did the dowel go? Did it get chewed up? If so, where are those metal filings? There's really enough reason in my mind for a complete tear down. But that's just how my mind thinks.
 
OK, understood; that is why I suggested the 3 bolt option: to get around the dowel hole issues. BTW, I had a cat like you new avatar cat; a really nice cat but he took nuthin' from nobody!
 
Thanks for all of the advice, were going to try and pull the cam out either today or tomorrow. Discussed it with the teach, time me that it would be next to impossible for what we have to drill that precisely into the cam and sprockets. Today I'm going to try to find that dowel pin and start getting ready to pull the cam.


RRR, my dad has similar thinking; pull the head, pull out the engine!
 
The dowel pin is designed to be used for alignment purposes ONLY and NOT take the rotational load. Proper tightening and retention of the cam bolt is what fixes the cam gear to the cam by friction. Somehow yours came loose or was not tightened properly.

I just happen to have a /6 cam in my office cubicle today so I took a picture. For your info, the dowel pin measures .250 diameter and it also protrudes from the cam face .25. This is what you need to get back on the road.
It looks like the hole in your cam is wallowed out so that's bad. If the pin is in the pan I wouldn't think it would cause any problems rolling around in there because it won't fit through the pickup screen. (unless it somehow ended up in smaller pieces)

If it was me, I'd replace the cam and not screw around with a repair. New stock replacement cams are available (Rockauto being one source) but then you'd also need new lifters. That would be a couple hundred bucks. Maybe someone on here has an extra stock cam with matching lifters they could donate or sell at a reasonable cost. A new timing set would then get your timing back like new. The one in the picture is headed out to Oregon Cams for a regrind.

One thing about /6 cams is that they are long. You should be able to pull it by raising/lowering,angling the engine to get around blockages in the radiator shroud area after removing the grille, bumper, etc. If you do decide to pull the engine, be forewarned that you are more than likely going to find other problems and things may snowball from there. Good learning experience though!
 

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I got a 67 cam but the lifters are shot, yours for shipping. Lifters are $6 a pop through Autozone but are far cheaper through rockauto. Still has pin in it. need to pull pump out 3" and ditributor as well as fuel pump, they all ride on camshaft. And the wear in the block around the cam gear is faced, unlike Daves69. maybe model specific. A torrington bearing would be nice if the block is grooved badly but youd have to then align the crank gear too.
 
Looking more at the cam sprocket groove around the cam, and with Pista's comment, I realize that I can't say if that is normal or not. The cam sprocket normally rides on the front of the block as the thrust surface but can't say if the groove is normally there or that deep.

I would suggest that you put the pix on the 'Engine' subforum of www.slantsix.org and see what the folks there say. I am becoming a bit concrned at that part. If it is really worn in that deep then the lifter alignment on the cam lobes will be way off. This may have happened prior to the previous cam sprocket change out.

BTW, Doug Dutra sells reground /6 lifter for less than new ones. He can be found on www.slantsix.org as 'Doctor Dodge'.
 
I will be replacing the cam, thanks for the recommendations for those. How long approx. does it take for a cam to be delivered?

So today we got a good amount done. My good friend who is helping me out on this got to stick around and remove the oil pump, fuel pump, and distributor as well as the pushrods (in which two of them were new; greet, so someone has been down this far) and rocker arms. Now to the lifters....those are being a PITA to remove. The teacher's concern is what some said about being out of alignment, and those lifters just walking around on that cam, causing burring and wear on both the cam lobes and the lifters themselves, which make them even more a pain to lift out. Obviously, that isn't good at all and would be even more trouble. Then again, it could be that they are lifters and are hard to remove anyways.


I'll be reposting this onto the Slant Six Forum too.
 
The lifters being hard to remove is normal. The lower portion of the lifter does not move up into the lifter bore in operation so can build up a ring of varnish on the lower edge. This is almost certainly what is hanging them up. Mine were varnished so badly that I had to flip the engine on a stand and drive them out with a maple dowel!

You DO have to put in new lifters with a cam. You CANNOT ever re-use lifters on another new or used cam...never! So get new lifters.

One check you can do for possibility of block wear by the cam sprocket on the front of the block is to check to see how far in the edge of the cam bearing is from the front surface where the cam rides. The front edge of the cam bearing should be 3/32 from the front surface of the block. (Of course, this assumes it was installed right initially....)

The concern for the front block surface being excessively worn is that the cam will ride further back than it should, and the lifter contact points, will be off and cause excess wear. Also, the oil pump gear will be mis-meshed with the cam, and that gear is a weak point. The distributor gear will be off too.

If the front of the block is worn, then I have to wonder where all the metal went! And how well the oil pump is working..... make sure you take that apart and measure the clearances and look at the wear on the internals. Any metal in the pan will go through there first.
 
Today was an extremely slow day. Managed to get the cam pull out about 3 inches, but kept getting caught on something or a lifter. We used lifter grips, lifter grips with a magnet, two powerful magnets, they would hardly budge. If they dropped though from the raised position, the cam would get stuck and stop turning. Hard to get much down there with the extremely tight space.

Is there ANY way to get lifters off without removing the entire head? Or did we just waste a day by trying to figure out a way around it? Since they weren't budging, could it be a sign that they mushroomed? Teach is very against pulling the head, and would actually rather to pull out the entire engine to go to the entire thing. I did order a new cam today (Thank you so much JohnnyDart!) so I'll be expecting that.
 
Later today my partner-in-crime on this one is going in later to work on it.....I'll tell him to check the oil pump if possible.
 
Since the varnish on the lifters is so common, I suspect the chance of mushroomed lifters to be pretty much nil. They are well hardened so would not be prone to mushrooming any way. The cam won't pull out with any lifter nearly in place. They have to be up about 3/10's of an inch or more to clear all the lobes. If you got it that far forward, however, perhaps the cam journals jut dropped in-between bearings and it is not lined up to slip into the next set of cam bearings. That thing is LONG so you have to hold it perfectly straight and hold it up. Just don't be jerking on it or wallowing it around or the cam bearings will be damaged.

Pulling the engine at this point is not a bad idea at all. with all the trouble you are having. If the block is worn where the cam sprocket rides on it, then some serious block work is needed any way. If the lifters won't budge, then you are kinda stuck at that, and you can inspect a lot of other stuff. Kinda sucks to have to do that.....
 
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