The Stovebolt Site Forums The Shop Area Engine Shop timing gear clearance

getting ready to put the new cam shaft timing gear back on and noticed that the clearance between the gears is pretty tight. according to the shop manual there is supposed to be some lash but this looks like there won't be any. i am using the fiber type gear with the orignal crankshaft gear.

should i be worried about this or will the fiber gear "settle" in once it turns over a few times?

Have you tried checking the lash with a dial indicator? Sometimes it's not noticeable by the eyeball method. If the teeth are actually running with no clearance, they will be noisy for at least a short time until they wear into a good running fit. The steel gear will eventually force-fit itself to the fiber gear, but that's not the best choice.
Jerry

i haven't actually measured anything as of yet, just concerned that the fit appears to be tight. not sure there are many alternatives given the fact that neither the cam nor the crankshaft can be moved to make more room and the assumption that all the timing gears are essentially the same size.

guess i will put it on and turn it over to see how it meshes up.

thanks lincoln.

If the block has ever been line-bored, the crank and cam will move closer together by a few thousandths. There used to be engine rebuilders' timing gears (and chains)made to compensate for line boring, but I doubt that they would still be available now.
Jerry

Sometime the only option is to use a used gear.
I have assembled engines with no backlash, with no problems, but I kept my fingers crossed for the first thousand miles.

thanks pre '68.

i have a one ton with with a 216 that i could poach a timing gear off of but just am not to sure about the faith i have in a gear that is as old as the one that failed.

lincoln, this is the first time in the history of this truck's life that the engine has ever been apart. i am just going to put it together tomorrow and hope for the best.

thanks for the input guys. wish me luck?!?

it fits!

actually it fits really well. i did end up pulling the cam shaft so i could press the gear onto the shaft, but it was worth the extra effort. everything lined up beautifully. got the head back on so today feels like real progress.

Sounds good! The machining on these oldtimers is usually pretty impressive! Modern CNC machines might work to closer tolerances, but it's still good to appreciate how close they could make stuff 50+ years ago.
Jerry