VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Loose timing gear

Any ideas on how to fix this would be appreciated.

I took the car out Sunday for a short drive, about 3 miles and when I returned I could hear a rattle from the engine that had not existed before.

I found it to be the timing gear on the front of the crank loose and bouncing against the timing cover.

See loose cog here

Just so we have this correct. The gear that is loose is the crank gear and not the timing gear.

I would pull the gear and install a new key. After trying the new key and it is still loose I would look for another gear. It should be driven on and not a bit loose to the hand.

If you are really into it, after the gear is removed you can take a sharp chisel and cut some hash marks all around the crankshaft. It is made from soft metal so it will not be difficult to make the hash marks. When completed, you should need a puller to remove the crank gear.

OK showing my complete novice mechanical skills what is a key and where can I purchase one?
I have contacted the main early chev importer guy in aus and he seems to think the crank as to be machined.

John,

The key is what fits into the shaft and slots into the gear.

That sounds nasty, never heard of it happening before. I would follow Ray's advice and would not think you need to look at machining. But would suggest you makes the marks evenly around the shaft.

Let me know if you get stuck for parts and I will see what I can find, but would think at a worse case if you cant make up a key yourself a local machinist could do it for you. You may find the key ways on both the shaft and gear have been worn oversize and a standard key will not fit.

Good luck, let us know how you get on.

Cheers

Ray

I've had this problem in my 27 Chev many years ago, and it was an easy fix. There is a Loctite product that fills gaps up to about 20 thou. It basically glues the crank gear to the shaft and if necessary it can be easily removed with a puller needing about 15lbs pressure. I found the crankshaft had been chiseled as mentioned by Ray, however it was still lose. After fixing with the Loctite I did many thousands of trouble free miles. CPJ maybe able to tell you the name of the Loctite product.
Unfortunately you'll take your radiator off to get to it. Maybe you can fix your badge while it's off.
Good luck mate, it's a pretty big job
Chris

Thanks for the info I wasnt looking forward to removing the engine.
Chris does this sound like the stuff you used?
loctite 660

The best fix for your problem,would be to use Loctite 680(about as strong as you can get),and,if you have to,just dimple the crank gear diameter with a smal centre punch.Also replace the woodruff key that fits into the crankshaft,as it will probably worn enough to let the crank gear rock on the shaft.Take a sample key with you to a REPCO or bearing supply company(I use CBC Bearings)and see if they can match it.you may have to buy a pack of 10.

Never knew you could buy woodruff keys over the counter, but do now thanks to CJP'S29

Cheers

Ray

Hi John,

How did you get on, all good I hope.

Cheers

Ray

Cure time for loctite 680 is 24 hours at 25 deg celcius. Its like waiting for water to boil. Should be ready to try in a few more hours.

That green glue seems to do the trick. Been for a drive round the block and no noise.

Hi John,

I am sure all will be ok. In my case I had a crank pulley that decieded to work a bit loose after 30 years. After picking a replacement with the smallest dia hole and applying a healthy coat of loctite, I did not relax till I had done a good high speed run to test. Even now I check it every few weeks.

Cheers

Ray