I managed to get the timing cover off and the chain on the right side has 1\8 inch play, while on the left hand side the chain is so loose that it's 1\8-3\16 away from slapping the block where the bolt holes for the cover are. I am Very confident this is the problem, but now I have to buy a timing chain cover because it's a 1 time use item(?). After this I will put insurance on it and drive it around until I know I can trust it again, then put it back into circulation.


​​​​​​Another issue I encountered is that I forgot about the tapered tip on the harmonic puller, (the last guy who rented it didn't put it back) and now I can't get the harmonic balancer bolt back in the crank. Can I use a drill bit to ream past where I deformed the threads on the end of the crank?

 

I haven’t heard of a timing chain cover being a 1 time use item. I forgot what engine you had so if it’s other than 5.7 I’m not sure about the cover.

I’m sure you picked up a gear set; cam gear, crank gear, and chain. Be sure to get a new timing chain cover gasket, crank seal, and water pump gaskets (5.7).

I don’t know how bad the end of the crank snout got damaged. You should be able to get the correct size tap and carefully run it in to “chase the threads”. If the outside edge of the crank snout also got buggered up you’ll need to carefully file / sand paper the burrs & bumps out or you will never get the harmonic balancer back on. Check the key way on the crank snout and replace the key if it’s damaged.

 

Well we may not know if the issue was the timing chain. The auto parts store gave me a thread shader but the inside is battered too badly. I tried many things and nothing worked. I have an idea of cutting a notch in thr thread chaser all the way back, compressing it with pliers then letting it open or wedging it open then bringing the chaser back through the crank by reversing it until the bolt will go in. Either that or welding the balancer onto the crank.

 

Don’t weld the balancer to the crank. You can drill out the hole and tap it for a thread insert. Take the bolt to NAPA and buy a kit the correct thread size. The kit should come with a drill but (specifically sized for the new hole), a few threaded inserts, the correct size tap for your original harmonic balancer bolt, and the hand tool to thread the inserts in with.

The bolt hole in the crank snub is quite deep. Just drill deep enough to run so that a couple threads on the end of bolt (when threaded in) will extend past the “bottom” of the insert. Don’t worry that the threaded insert is not “as long as you would like”. All that bolt does is hold the balancer in place; the balancer is a ‘press fit’ and the key way keeps it located on the crank snub in the correct position. The majority of the “holding force” comes from the press fir.

Also, be sure the end of the harmonic balancer does not have any burrs, but dents, or damage do you can press the balancer back on.

There is a special tool used to ‘press the balancer’ back on. The end of that tool gets threaded into the crank snub threads you just repaired. You set the h balancer up to the crank and slide A “spinning bearing” on to the threaded install tool. Then a nut goes on the the tool and you tighten the nut down to the “spinning bearing”. As you keep the H balancer aligned with the key way and perfectly perpendicular to the crank snub so it will slide in straight, tighten the nut which pushes against that spinning bearing. As you tighten that nut the tool “drives” the H balancer back in to the crank.

Take a good look at the H balancer to see how far it had originally been pressed in. It has to be VERY close to where it was or your V belts or serpentine belt pulleys will not line up with your accessory drive pillows.

You do not need any lube or loc-tite. The washer behind the head of the H balancer bolt is a cupped washer designed to flatten when tightened which keeps the bolt from vibrating out.

 

Thank you for this good info. I have good\bad news, I bought the right tap and carefully turning\correcting tapping it and staying on track, I was able to fix the threads! I got the bolt in no problem.

Now I have another problem. The timing chain they sent me is like a motorcycle chain, not the metal layered stock one. The stock one has some pretty good pitting in the gears (see pics if I can attach them). But the new one is way too tight. Also the cam gear looks like it is not fully going on because it's hitting the two bolts adjacent to the camshaft. If you look at the pics the stock timing gear is much more offset.

Should I be looking for a 97 timing chain instead of a 96? My truck is a transition year and has obd 2, so maybe it's more 97?

Old gear wear

Old timing gear has much more offset away from block than the new one. New ones rubs on bolts next to camshaft.

Old timing chain

New roller type chain? Any good? Too tight it seems

 

Great job on getting the threads fixed! That new timing chain is a double roller and better than the OEM.

How are you installing it? What I do put the crank gear on and with the chain draped over the cam gear place the chain in the crank gear and the slide the cam gear with chain into the end of the camshaft. Some are pretty snug - zero play on the sides of the chain. It may be so snug that you might cuss a bit trying to get the 3 cam bolts in! There should be a “pin” in the end of the cam and there’s an alignment hole for that pin in the cam gear.

Make sure you line up the crank gear and cam gear timing marks. If you haven’t spun the crank or cam it should line right up. If that’s the case after the cam gear is bolted up (usually 3 cap screws and a locking tab) you can rotate the engine over by hand slowly to verify the timing marks in fact do line up.

Don’t forget to install a new timing cover gasket and a new seal for the front main (crank seal that goes in the timing chain cover).

 

Oh, check with the parts guy to make sure they gave you the correct gear seat. You can do like you said and see if for some reason GM changed the cam gear. I don’t know why there would be a difference. I have to think on that.

 

I looked at the pictures again. When you said “too tight” on the chain did you mean the chain doesn’t sit down in to the teeth of the cam gear? If that’s the case the set they gave you is mismatched.

I wonder if the new chain thickness makes up for the difference in the offset if the cam gears.

You could test fit each cam gear without the chain to see how they each fit. You could also put the cam gear & chain on but not in the crank gear so you can get an idea if the chain hangs properly to align with the crank gear.

 

Thank you for all the good advice and help!

I began grinding the cam gear when I realized the holes don't line up. So now I definitely can't take it back. They sent me the wrong timing chain set completely. Great. But at least I know now what the problem is. The cam gear was grinding on the camshaft retaining bolts. I will try and keep you guys updated. This truck also needs a transmission, I pulled one from a boneyard and I will put in all new solenoids, I bought the entire pack of them new.

 

Dang. Good thing the timing gear sets don’t cost tons! You’re lucky you have a decent bone yard near by too.