[dbuff]

On the 60's V8 engines that use a timing chain.

I am curious if there are ever any signs that a timing chain may be on its way to failing?

What is recommended time / miles before they should be replaced?

Anyone ever had a chain break on them?

 

[johnsongrass1]

Poor performance and erratric valve timing.

Breaking a chain sucks.

 

[[email protected]]

Irratic performance, irratic timing. The timing mark will jump around when viewed with a light.. In severe cases a hole worn thru the cover by the chain is a good indication. Seen it happen several times . Chevy and Ford. I once bought a sick Suburban and pulled the cover. It had one (1) tooth left on the nylon covered factory gear! It still ran, but was a super slug. One cough and it would have been all over!

 

[troy-curt]

usually there is no warning. They don't break very often, just strip teeth off.

Troy

 

[machine shop tom]

Gee, I always thought that they ran ERRATICALLY.

You'll probably also hear a rattle or tick from the timing cover.

tom

 

[troy-curt]

I've seen them running good, shutoff for the night, and never start again. If it is making noise and running bad, it should checked.

Troy

 

[killerformula]

yeah they just stretch and get sloppy, timing will retard and performance will suck. There's really no warning sign, but if you have 150,000 on a metal set or close to 100,000 on those crappy nylon ones from the 70's, be reasonable and change the thing.

K

 

[Wrencher]

Get a buddy to help ya, have them watch the rotor while you turn the crank one way until the rotor starts to move, mark the balancer and timing cover, turn back the opposite direction until the rotor moves again, mark and measure, 1/2" or less is acceptable.

 

[jimfulco]

My '72 Nova 350 was slapping the inside of the front cover at 50,000 miles. I had a '78 305 that just had a slight hesitation off-idle that I couldn't fix with carb or ignition work, but a new chain at ~70,000mi. fixed it right up. Stupid plastic parts!

 

[killerformula]

My '72 Nova 350 was slapping the inside of the front cover at 50,000 miles. I had a '78 305 that just had a slight hesitation off-idle that I couldn't fix with carb or ignition work, but a new chain at ~70,000mi. fixed it right up. Stupid plastic parts!

seen it happen a bunch of times. Told ya!

K:thumbup:

 

[[email protected]]

Early hemis come with hardended steel sprockets on both ends and a chain strong enough to tow Oregon.

 

[sbchevfreak]

A loose chain sounds kinda like a bunch of wet rocks being swirled inside of a coffee can...

 

[troy-curt]

I've never heard a lose chain make noise. If it did then it's to late.
I've heard them rub the cover a few times, but by then you probably would not get around the block.

I'm sure there is some exceptions.

Troy

 

[sbchevfreak]

I should have said really loose.

 

[killerformula]

last time I heard a loose chain the motor backfired twice and the motor didn't run again for about two months.

K

 

[87442lover]

usually there is no warning. They don't break very often, just strip teeth off.

Troy

Pretty dead on, there usually is no warning that I know of. Broken a few before, never had irratic timing, missing, or anything, was just driving along and it died. Turned the key, it turned about half over and then SCREEEAAACCCHHH!!! All over for that motor.

Now a timing belt will sometimes be noticable. I once heard a slapping/scratching noise coming from the engine (ford 1.9) Checked all the accessories and all was good, pulled the cover and a good size piece was sticking up flapping against the cover. Oh yeah, it had also ground a hole into the plastic timing cover, I still have it if ya want pics. :thumbup:

If it's a stock 80's or 90's car with factory timing set and near 80,000 miles, I would replace it. Those nylon/pot metal gears just dont hold up to much.

 

[dbuff]

Get a buddy to help ya, have them watch the rotor while you turn the crank one way until the rotor starts to move, mark the balancer and timing cover, turn back the opposite direction until the rotor moves again, mark and measure, 1/2" or less is acceptable.

Wrencher -
Removed plugs and tried this and all was fine.
That is just what I needed.

Many , Many Thanks....

 

[Wrencher]

:thumbup: Nothin like good news!!

 

[84_sportcoupe]

OMG!!! so what you are telling me that is the gears in my 84 305 with 187000 miles
never rebuilt, are made of nylonain: well looks like i need to get that replaced pronto.... man im glad i read this!! you guys rock...... that really explains a lot of problems ive been having... i should have replaced the whole timing set already but i only drive the car once or twice a month. so i wasn't in a huge hurry.

 

[87442lover]

OMG!!! so what you are telling me that is the gears in my 84 305 with 187000 miles
never rebuilt, are made of nylonain: well looks like i need to get that replaced pronto.... man im glad i read this!! you guys rock...... that really explains a lot of problems ive been having... i should have replaced the whole timing set already but i only drive the car once or twice a month. so i wasn't in a huge hurry.

If you open that engine up and see that the gears are made from nylon, could you PLEASE post some pics of the set? I would love to see a nylon set that made it to 180,000 miles. I want to see the condition of these gears, but more than likely they are all pot metal if they have made it that long. I never have seen an original set make it past 127,000 miles. No, I'm not trying to insult anyone, I really would like to see what a set of nylon gears looks like with 180,000 miles. Never seen one last that long.