Replacing timing chain question. RB

GOLDMYN

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Hi, Changing the timing chain on my 1968 Chrysler TNT 440. everything was proceeding fine until. We measured the new timing chain crank sprocket and it just slide on (partial) it also has some slight clearance. Is this normal. the sprocket is Melling 40203. when I say the sprocket just slide on, we only put it on as far as the old one (still installed) would allow. if I'm making sense. also any tricks to getting the cover crank seal of w/o damaging everything?

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You must take the old one off, it will be loose on the front part of the crank with a sprocket already on there.

Also the sprocket gets clamped between the step on the crank and the harmonic balancer.
 

GOLDMYN

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That's what I was wondering, we were just checking the front part of the new gear, w/o taking off the old, I know we must take off the old, just the old crank sprocket fit tighter than the new one, sorry if I'n not making sense.
 

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A little confusing, but maybe I get what you are saying. You must take off the old gear to judge how the new one fits. I like to partially trial fit them also before final assembly without the chain, but the old gear is gone. New one should fit tight and if doesn't, then I would use green Lock Tight shaft lock on the gear. Tips.... also use red or blue Lock Tight on the cam bolt, make sure the vibe damper doesn't have seal wear groove in it, put white grease on the cover crank seal and the loosen the front four oil pan bolts to aid installing the timing cover so as less disturb the cover gasket and put a dab of sealer in the pan to timing cover corners.
 

GOLDMYN

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OK, putting the harmonic balancer back on and it would only go half way, rubber mallet helped move it further on. but still not up to torque value, (crank bolt/harmonic balancer keeps turning. ANY tips on how to stop the crank pully from turning so I can torque the bolt?
 

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Pull it back off. Get or make a center crank bolt nut drive installer. Make sure bore and shaft are smooth, place damper in front of a space heater for about 20 mins, wear gloves and put it on using the center bolt installer.
 

PH27L7

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You can just take a piece of scrap wood (2 x 4, plywood, whatever) of the right length & using the pulley as a template drill a couple holes to bolt to the damper & a big hole in the middle using a hole saw. Works great for differential pinion nuts as well & costs nothing. I lube it with some light oil & have never needed to add heat. I'd be scared of that due to the sandwiched rubber in the damper.
 

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Been heating them for over 40 years and still running some from the '70s. Not talking about 500 deg, just around 150deg will help. You know the engine gets pretty warm while running. Just don't beat it on.
 

GOLDMYN

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You can just take a piece of scrap wood (2 x 4, plywood, whatever) of the right length & using the pulley as a template drill a couple holes to bolt to the damper & a big hole in the middle using a hole saw. Works great for differential pinion nuts as well & costs nothing. I lube it with some light oil & have never needed to add heat. I'd be scared of that due to the sandwiched rubber in the damper.
John, I'm sorry, I'm lost,2x4, what, 3 or 4 feet long so you can hold onto it and bolt it to damper, isn't 2/4 too thin. sorry, I see the principle, just not the mechanics
 

PH27L7

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John, I'm sorry, I'm lost,2x4, what, 3 or 4 feet long so you can hold onto it and bolt it to damper, isn't 2/4 too thin. sorry, I see the principle, just not the mechanics
A 2 x 4 is probably thicker than you need but I've used that before. You don't really need to hold it, just let it hit something solid like the floor, 2 or 3 feet long should be plenty, torque is only 135 ft-lbs. If you hate the idea you could use a special damper install tool from an auto parts store, not really necessary though as mopars have a huge damper bolt unlike some other makes.
 

GOLDMYN

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**** UPDATE******What about placing a wedge (wood) between the ring gear and transmission casing, wood wedge between ring gear and trans casing did the trick, we were able to torque to spec. Thanks forum guys!!
 
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PH27L7

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Don't see how that would work with an auto trans in place, no place to put it. I checked a spare damper & it appears there's enough room to fit a pry bar between a couple of the pulley holes. Get a couple of grade 5 bolts (5/16"), they may bend a tad but no big deal.

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GOLDMYN

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I dropped the inspection cover, flex plate bolts torque convertor which has the ring gear attached, placed a small block of wood at the lowest point between the ring gear and transmission casing. as we turned the crank bolt the ring gear is stopped by wood wedged in there.
 
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