When is a timing chain in need of replacement?

[SuperDave]

With all the talk here about cams, little attention is given to the timing gear set. To neglect the timing gear set is to ignore an important component that can have a negative impact engine performance.

I've explained my method of checking the condition of the timing gear set WITHOUT disassembling ANYTHING.

Would someone please summarize my method so that others may benefit? (I've explained it numerous times here and want to see if others understand)

 

[akd67]

When its worn out.

 

[Ozsum67]

The skinny of it is to examine the excessive play or rotation of the distributor shaft.

 

[SuperDave]

akd67: And how do you DETERMINE when the chain is "worn out"? What IS "worn out"?

Oz: Ditto above. How to you determine what is "excessive play" or "rotation" of the distributor shaft?

Remember this is supposed to be a simple anduseful way to measure deflection or slack in the chain/gears.

 

[akd67]

Remove distributor cap and rock the crank back and forth. The crank should only turn 6-10 degrees either way before the rotor moves. Any more and its time to take a closer look.


Edit: I have never read about "your" method. This is the way its done in our shop.

 

[SuperDave]

Remove distributor cap and rock the crank back and forth. The crank should only turn 6-10 degrees either way before the rotor moves. Any more and its time to take a closer look.


Edit: I have never read about "your" method. This is the way its done in our shop.

Good. I explained it in similar terms here several times hence I consider it to be "mine"; not that I own it but that I practice it even in doing simple "tune-up" work.

I know that this is often overlooked and it is often NOT understood by many. Seems so basic. Glad that you practice it also.

 

[zookeeper]

Although it may seem odd to you, there are several talented mechanics that use similar methods, therefore it's kinda tough to claim credit for a method. I was always taught (by my Dad, a master mechanic if there ever was one) that if the center links touch when squeezed lightly (holding only the chain, no gears) then it's time for a new one. My method is much simpler: if you can see it, replace it. Timing sets are far too cheap not to replace it whenever you swap cams, and I'm cheap!

 

[akd67]

Nice to have the procedure confirmed.

 

[akd67]

My method is much simpler: if you can see it, replace it. Timing sets are far too cheap not to replace it whenever you swap cams, and I'm cheap!

Thats a good one too.

 

[Ozsum67]

akd67: And how do you DETERMINE when the chain is "worn out"? What IS "worn out"?

Oz: Ditto above. How to you determine what is "excessive play" or "rotation" of the distributor shaft?

Remember this is supposed to be a simple anduseful way to measure deflection or slack in the chain/gears.

Since the question has been answered, it would be overkill to answer it again, but I know of only 2 ways to turn the distributor....by key or by breakover bar on the crank. The key method would tell you zip.

 

[ashford]

i just grab the balancer and rotale left to right i can usually feel when the chain tightens. if its more than 10 degrees buy a new chain set and a new better cam if ya want

 

[foghorn67]

good thread. Timing chain sets cost very little, even for your well known brand names.

 

[Fostang]

Who cares how old it is just change it your already in there, cheap insurance to keep the car from jumping timing.

Or go with my favorite gear drives.

 

[StangDreamin']

I don't know if this is part of SD's wisdom or not; but it's something that I've learned from painful personal experience:

If you live in predominantly WARM climates; you might be well advised to pull the timing cover of ANY original motor you don't know intimately! Ford, in their infinite wisdom; actually manufactured their cam gears undersize, then molded nylon over them. This was done to reduce noise from the nose of the motor. As the motor ages - especially if it lives in warmer climates - that nylon grows extremely brittle and begins to flake off! Add in the slightest amount of slop in the chain; and you have a situation ripe for mis-time if/when the chain "jumps a tooth or two".

Two things: 1.) You'll be forever trying (and failing) to set the carb and the distributor advance DOWN! 2.) Let enough of the nylon flakes get into the oil pump pickup screen and you'll be wondering what happened to your oil pressure! This happened to every Ford my Dad owned (starting with his much-driven '66 LTD in '68); and in both my '73 Gran Torino and '72 F100. It was probably going on in the wife's hi-mile Tempo; but I never had the reason/guts to pull the motor to pull the timing cover!

When I finally get my 'Stang; unless I can be assured the motor has been properly rebuilt; that water pump and timing cover are coming off and the chain and gears are being replaced with all steel parts SOONEST! I can live with a little timing chain noise. I just don't want to have to chance the "jumped-time" scenario and it's inherent dangers (too the motor); and I don't want to have to order an oil pickup because the mess is impossible to remove from the screen (Torino)


Still Dreamin'

 

[65fastback2+2]

when it dont go no more, right???

 

[SuperDave]

Although it may seem odd to you, there are several talented mechanics that use similar methods, therefore it's kinda tough to claim credit for a method. I was always taught (by my Dad, a master mechanic if there ever was one) that if the center links touch when squeezed lightly (holding only the chain, no gears) then it's time for a new one. My method is much simpler: if you can see it, replace it. Timing sets are far too cheap not to replace it whenever you swap cams, and I'm cheap!

Zookeeper: I though we could be civil about this BUT I asked to have a description of way to check the chain and gears WITHOUT diassembling anything. Your method involves REMOVING THE chain and then visually checking the links themselves.

How is that simpler than "my" method? Hmmmm? I never claimed "credit" for the idea but I CAN tell you that I am the only one here to have described it in detail and I've done so several times in the four years that I've been here. I wanted to see if anyone learned from my description or whether I was wasting my time. I did so with the intent of helping people rather than "toot my own horn", "claim credit" or explain it once again.

 

[TheDRake49]

1. My 2 cents; anytime I see a reply or statement from SuperDave, I am going to read it and learn from what he has to say.
2. I am glad to see someone post how to check the timing chain.
I went to pull the water pump off of my 68 when I broke some of the bolts (did not take the time to spray bolts), pull car to a shop and told them while you are in there replace timing chain. As stated timing chains are cheap and my 68 is running better now than it has in 6 months

 

[Route666]

Any extended wear life from a gearset instead of a chain? Enough to substantiate its use?

 

[Ozsum67]

Zookeeper: I though we could be civil about this BUT I asked to have a description of way to check the chain and gears WITHOUT diassembling anything. Your method involves REMOVING THE chain and then visually checking the links themselves.

How is that simpler than "my" method? Hmmmm? I never claimed "credit" for the idea but I CAN tell you that I am the only one here to have described it in detail and I've done so several times in the four years that I've been here. I wanted to see if anyone learned from my description or whether I was wasting my time. I did so with the intent of helping people rather than "toot my own horn", "claim credit" or explain it once again.

Dave, there are many ways to skin a cat. It did seem that you were claiming ownership of "the" method. I personally know of one of "your" wisdoms.....the "cheap ain't good" one, that was copied from a well known economist from the 1920's.

 

[SuperDave]

Perhaps we can meet in the middle on this.

The method that I ("mine" or not) propose allows the chain and gear set to be checked WITHOUT removal of engine components. This was the point of MY thread.

Zookeeper's suggestion requires digging into the engine to visually examine the timing chain and does not say anything about the condition of the gear set.

Which is "simpler" or more useful? Readers may decide for themselves.

I agree that timing SET (cam and crank gear plus chain) replacement is often adviseable when an engine gets sluggish or anytime the engine is opened up for other repairs. Such considerations are often ignored by the inexperienced.

I am weary of the repetition found here. Some topics deserve to be reviewed occasionally because new people come here all the time. If I appear arrogant and "all knowing" it is because I have a lot of experience to support my ideas. If readers find that offensive, they don't HAVE to respond to my posts. Just as I don't respond to some posters, I invite my critics to do the same.