Timing Chain Inspection and Replacement

[Tynan918]

Is the fan, water pump, and harmonic balancer the only things I remove to get to the timing chain cover ?

 

[Tynan918]

By the numbers on your engine it is an early 80s 305 and came with the 6.75" balancer. Most 350s came with the 8" balancer.

All high RPM engines came with the 8" even it they were smaller displacement than 350 (Like the 302 in the Z28 and corvette 327s). The balancer is tuned to the RPM range the engine is rated at so high performance engines have bigger balancers. Some trucks might have bigger balancers too.

Just removed and measured mine tonight, it's 8"...

 

[Tynan918]

All 80's stock 305 in Monte Carlo had the 6.75" balancer...

 

[Tynan918]

Moment of truth... I'm down to the timing cover...

What size are the timing cover bolts and what size are the oil pan bolts ?

 

[Tynan918]

Timing cover pulled off...

 

[Tynan918]

The timing chain... Single roller...

Both sides have some slack, is that normal (video in post #144).

Crankshaft gear looks older than the rest of the timing chain set...

 

[scoti]

Timing gear & chain don't look old.
'Slack' looks normal to me.

 

[Tynan918]

Timing gear & chain don't look old.

Looks dirtier than the camshaft gear... Should the chain have that much slack ?

 

[scoti]

Looks dirtier than the camshaft gear... Should the chain have that much slack ?

I watched the video & didn't think it was bad. But..... I'm no career GM mechanic either.
Gear & chain are definitely not 'original' (old) parts. They've been replaced @ some point judging visually.

 

[ELCAM]

Crank gear looks original. Chain and cam gear look new. I don't think there is any thing to be gained replacing any of it.

Keep in mind the original cam gear is nylon on steel, the nylon teeth wear out fairly quick so the gear has to be changed.

 

[scoti]

Another suggestion....

You have a lot of the front pieces off. If it were mine.... I would pull the accessory brackets off & clean the block.
Get things as clean as possible so when you put it back together, it's much easier to see if there's an issue w/sealing anywhere.