Timing and crank gear

[28 fast faton]

I am replacing my head with a H.C head and my rad at the same time. I also want to replace the timing gear and the crank gear. I was thinking while the head is off and the rad is out I could remove engine mount bolts and jack up the front of the engine so I can replace the two gears. Is this possible or does the engine need to be removed. Thanks in advance

[BRENT in 10-uh-C]

Remove the two bolts on each side of the rear motor mounts which will let you raise the engine up a little higher in the front crankshaft snout area. Then you are good to go without removing the engine.

[columbiA]

Be sure to remove the throttle assy thats bolted to top of F-W hsg or you will bend it.

[Tom Wesenberg]

Most of the crankshaft gears I've removed have been extremely tight and I had to use my press to remove them. If you have an oxy/acc torch that will be a big help.

Is there a problem with the gears that are in place now? The cam gears with the aluminum center and fiber outer are prone to getting loose between the different materials.

[Patrick L.]

The crank gear can be a real PITA. But it can be removed while the engine is in the car, it'll take a REAL puller and heat. Don't beat the new gear into place against the babbitt. Make yourself a 'pusher' and push the gear into place. Heat is a friend when doing this also.

[CarlG]

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While you are at it -- get a set of Dan Mc's bronze timing gear and heat treated crank gear. Last time you will have to do that.

[James Rogers]

You guys that suggested using a torch do realize there is a babbitt bearing just behind the crank gear, RIGHT? Heat + babbitt = baddddd.

[Mitch//pa]

i am with NOT using heat, just a gear puller

[Kohnke Rebabbitting]

I wouldn't even change a gear like that myself!

Pull the Motor, press the gear off, clean up any score marks, make sure the 1/2 moon key fits, and then stand the crank stright up.

Make sure the timing mark is up, heat the gear to the first color change, which isn't much, and drop the gear on.

That way there is no rolling metal bits in front of the gear off the shaft, and Key, and no stress on the crank shaft.

Like James says heat is not your friend!

Babbitt does not have to run out of the bearing, as heat will loosen the babbitt from the wall of the Block, and still stay in place, to break up later in miles, and its all over with.

It takes more time talking about pulling the motor, then doing it.

[Patrick L.]

You need to use your head with heat and not get carried away. Its a really hard job without it.

[James Rogers]

Heat her up, I can use the business!

[28 fast faton]

Thanks guys. To the question what is wrong with the gears. I think the crank gear has a wobble . I bought the motor as a rebuild with few miles and it appears that is the case but it has a slight clunky noise when it idles and when I stick the timing pin in the hole the pin moves in and out slightly so I thought I would change the timing gear and might as well change crank gear as well. Crank gear might be fine.

[Joe K]

Changing the timing gear is a challenge to get that foolish nut thingy off. Some of the parts vendors now sell a tool that is designed to fit the flats on the dedicated nut.



Still, it will be a challenge to get it off. Think of pulling on it with a breaker bar and then giving the bar arm a sharp rap with a hammer to shock the nut into starting. It's not unusual to break the timing gear (or have it crumble) simply getting it off. (i.e. protect your oil pan which will be right below this with a shield/saran wrap.)

I can see changing it out for a bronze or aluminum gear. Most of the wear occurs on the fiber gear.

As to the pin moving in and out are you not sure you're just seeing it toggle through the timing pin divot? You may want to have a spring and plunger (or at least the spring) in case one or both is missing/broken.

Just some thots.

Joe K

[28 fast faton]

It is definitely a wobble because it does it as I turn the motor over with the starter

[Purdy Swoft]

I replaced both timing gears on a double A truck that I had with the engine still in the truck . Besides some of the good instructions that have been given, the oil pan will HAVE to be removed. You simply can't get the crank gear off with the oil pan in place.I used two of the spark plug with Eye bolts screwed into the head , a short chain with two hooks and my engine hoist to support the engine. You've got to remove the the ratchet nut and crankshaft pulley. I used a three arm puller, a wrench and a drilling hammer to remove the crank shaft gear. You will do best if you go ahead and remove the cam gear first, while the crank gear is still in place to help support it. I mostly use a cold chisel and hammer to remove the cam gear nut. Most of the engines that I have torn down over the years, show evidence that the cam nut has been removed and replaced in this manner , in the past. I usualy replace the battle scared cam nut with the new hex style nut that is easy to remove and easy to torque when you tighten. I used No heat on the crank shaft gear to remove or replace . You can make a tool to push the new crank shaft gear in place. You will need a short piece of strong pipe with an inside diameter just large enough to slide over the end of the crankshaft with a little clearance, a couple of heavy washers at least the size of the outside diameter of the pipe and a bolt the same size thread as the crank shaft ratchet nut , with enough length to push the gear in place when tightened. I used a new crankshaft key and oil slinger. I used a bronze cam gear and matching steel crank gear. I feel that either the aluminum or bronze cam gear will last a lifetime. With a helper I was able to do this operation in about a half day.

[Joe K]

I seem to remember the thread of the crankshaft nut/crank ratchet as 5/8-18NF? Allthread and a grade 8 nut and hardened washer and pipe could be used to put on the new gear?

The gear can be heated using an incandescent 100w light bulb and simply balancing the gear centered on top of the bulb. In a short while the gear will be too hot to handle which is your cue.

Joe K

[Purdy Swoft]

I have used the 100 watt incandescent light bulb trick to heat the bearing for installation on the input shaft of the transmission and it works like a charm. I haven't tried it on the crankshaft gear but it should work. it has been said that if heated to the next color change, not too much heat and it will slide in place.

[CarlG]

I heated mine to 500 degrees for 30 minutes and it still didn't slide on all the way, still had to press it the rest of the way.