There is a seal in the timing gear cover. When you pull the harmonic balancer off you can see a seal in the cover.. the balance slides thru this seal. The balancer is pressed on and there is a wooddruff key in the crank shaft (actually 2 of them on mine only one is inside the timing cover) Combination of pressed on and key that fits in a groove on the balance keeps it in place.

The seal can be bought separately at any parts house. I think the first one I bought was less than 8 bucks... Now, I had to replace the timing chain this weekend as I was going to paint the timing cover and notices gouge marks where the chain was hitting the left bottom side of the. Depending on mileage you might want to pull the timing cover.. but that means dropping oil pan and idler arm suspension.. Search on harmonic balancer and you can find all the tricks...

Except the boiling water trick didn't give me enough expansion.. going to try the hone trick.

As far a seals, I bought one separate,, I bought a new timing cover gasket felpro set.. and one was in it.. and the chrome timing cover had a third one. If you pull the timng cover, be sure you wooddruff key is in place, put the seal in the cover off the car. If you just want to replace the seal.. go to hardward store and get a 1 1/2 to 2inch coupling. It fits the seal diameter and clears the shaft and wooddruff key... Much easier to tap seal in as it evens force consistantly around the seal.

Good luck.

Now if someone can just tell me the clearance.

 

Suggest No oil on crank snout, keys-keyway or damper bore ... but do use some silicone/RTV in damper bore & keyway ... hot oil can push past the keys-keyway & out the front ... silicone serves both as install lube & seals it. Grease the outer diameter of damper snout so lip of seal in timing cover don't run dry on startup.

Suggest proper install tool ... if you do, you can feel it when damper snout seats against crank gear.

 

I have been fighting with this balancer for weeks... between frustration and blood I am losing... I had to put a new (chrome) timing cover on and chain because chain had so much slack it was hitting the cover. Now I thought today...I'm going to see if the chrome one is a different thickness but I know it's not. No matter what I do I can only the the balancer to go on to the same spot looking down it looks like about 1/4of inch to far out and if you look at pulleys they confirm the alignment problem. I have started loosening the oil pan bolts and hope i can lower the front of pan enough so I can take the cover off.. I figure with the cover off I can try to slide the harmonic balancer on and see what in the devil it's hitting to stop it from sliding on farther. Now yesterday I took it to a machine shop and had it honed out and it slid easily almost to or right to the darn spot it stops at... If I put my first finger in it's about 3/4 to 1 inch to the hole where the bolt threads in. It can't be on far enough it seems... I'm wondering it some how it's hitting the second wooddruff key.. Any ideas appreciated...

 

I just measured the stock L-48 that I pulled from my running '73 that is on the stand in my garage.

The inner bore is exactly 1" out from the end of the crank shaft to the outside of the balancer.
Hope this helps

 

Thank you Bob, you confirmed what I figured out last night after spending several hours lowering the pan again... pulling the timing cover and the chain, determining the bottom gear was against the crank, putting the balancer on and determining the balance was going right up next to the gear, measuring and learning what the spec you gave and then pulling the balancer and putting the cover and pan back on. ARGH IF ONLY I HAD READ YOUR POST FIRST. but I didn't think I'd get such a quick response...... Thanks for confirming that distance... I guess the other pulley's just look a little out of alignment. I guess when I tighten things up maybe they will align closer than they look. Thanks again for taking the time to measure that because I still had my doubts after I measured.

 

Even If you read my post first you probably wouldn't have rested easy until you dropped the pan and saw for yourself anyhow

 

True, I felt better after looking and seeing but you confirmation made be feel real good. I forgot to add.... THE WOODRUFF KEY mentioned many posts back mysteriously came out of hiding and was laying in middle of my walkway between car and tool bench. I swear it was grinning at me... But the good thing is, if I hadn't dropped it, I wouldn't have pulled the timing cover off and the pan and wouldn't have found the timing chain was in such bad shape.

Thanks again for all help.. if I'm lucky I'll get it all back together this weekend.

 

Friday nite, I got everything back in place except for the bottom cooler line, and 2 hose clamps. It was 1130pm and I knew the bottom cooler line would win the fight. This morning I finally managed to get up and move, felt like a tank had run over me and was parked on me still. Got oil and antifreeze and put the bottom line on and the clamps. I made sure I had no extra tools or parts loose, filled her up with oil and coolant. Got in the drivers seat,,, had the fire extinquisher ready.. said a prayer and turn the key... AND IT STARTED RIGHT UP.. drove it around the block a few times and looked for anything major wrong.. I will drive it on ramps tomorrow and check closer for leaks but nothing poured out.. Got the neighbor to help me put the hood on,, took it and washed it and drove it around for a while.. All seems good so far. Thanks for everyone's help and advice...