[39chevy]

How much slack in a tc before it should be changed? Tia, Dana

[timothale]

If the engine is apart I change them with new gears and a double roller chain. If it is a SBC with the nylon teeth change it. To check with out pulling the engine apart I pull the Dist cap and watch how much the rotor moves when turning the crankshaft back and forth with a socket and breaker bar on the big pulley nut, . My guess is if it has more than 5 * i change it.

[hcompton]

Originally Posted by 39chevy

How much slack in a tc before it should be changed? Tia, Dana

if you can see it then replace it. Never put a motor back together with old timing chain. and any more slack then stock is not ok. If its not a double roller replace with a good chain is only 40-50 bucks. Less if you get a good deal.

[vinniekq2]

I had one engine that the chain was so stretched that it was hitting the cover.It did not run well. There is a very good reason why replacement chains are double and gears sets are metal. So many reasons to change timing chain sets.

[BigEsGarage]

Originally Posted by 39chevy

How much slack in a tc before it should be changed? Tia, Dana

Like most have stated if it's apart; replace it. If it is something that your on the fence about, a rebuild perhaps and need a good reason; replace it. I've never given thought about the service limit on a fixed timing chain. I say that because I'd replace it but something like a 64 Mercedes 220b, 6cyl or a Suzuki, GLS800, you never know, are adjustable. In that case you would look at how much adjustment is left bla bla bla because it's now a $250.00 chain W/O gears.
What's the engine? Just curious, I'm guessing a good-ol Chevy.

Cheer's

[birkey]

Put a ruler parallel with the chain and use a machinists rule perpendicular to determine the slack. I believe 1/4 inch is MAX.

[hcompton]

Originally Posted by BigEsGarage

Like most have stated if it's apart; replace it. If it is something that your on the fence about, a rebuild perhaps and need a good reason; replace it. I've never given thought about the service limit on a fixed timing chain. I say that because I'd replace it but something like a 64 Mercedes 220b, 6cyl or a Suzuki, GLS800, you never know, are adjustable. In that case you would look at how much adjustment is left bla bla bla because it's now a $250.00 chain W/O gears.
What's the engine? Just curious, I'm guessing a good-ol Chevy.

Cheer's

Well lots of motor cycles these days have adjusters on the chain. But its not really for adjustment especially in cars. Its only for install and rebuild because the chain needs tension so they put a tensioner in place. Yeah you can adjust it but normally if they stretch there toast. Usaly its not recommended to adjust chains in cars if they are factory set as most adjuster are spring loaded and your only adjusting tension on the spring. Some older motorcycles have chains that stretch a little and some stretch as thye break in but its not like a rear drive chain where ypu adjust it until its end of life. They run in oil and should not wear or stretch.

In any case same holds true for all if you have it in hand or can see it replace it.

Hope that helps