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94 3.9 Timing chain problems

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  #1  
Old 11-04-2018, 12:26 AM
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Default 94 3.9 Timing chain problems

Bought my truck a bit over a year ago with 226,000 miles. I've put about 10,000 miles on it and there has been a timing chain rattle the entire time so I finally decided it was time to replace it. I'm not really a mechanic but I figured it's time to learn and didn't seem too hard to do. After hours of work I get the timing cover off and see that the camshaft timing mark is on the top and that the chain is pretty loose. I removed the old chain and put the new one on to find that the mark is still pointing up and the chain is slightly tighter but still loose. What would cause the mark being on top and is it going to affect anything? Why would a brand new "heavy duty" double roller chain be loose? The engine is at TDC with the rotor pointing at the spark plug wire for piston #1. The timing set is a Cloyes C3028x Heavy Duty Speed Set from RockAuto. Thanks.
 

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Old 11-04-2018, 09:31 AM
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That's acceptable.

Generally, folks want to install the gears dot to dot, just puts a different cylinder in firing position. So long as you don't move anything while the gears/chain are off, it's all good.

There was a tensioner available for the V-6 as well, but, it was for use with the morse style chain, I don't recommend them for the double roller, tends to eat the 'slider'.
 
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Old 11-04-2018, 12:22 PM
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Dot up puts cylinder 1 on the EXHAUST TDC; dot down puts cylinder 1 on the COMPRESSION TDC.

Remember, the crank spins twice for every cam revolution.

You could have turned the motor over 1 revolution; that would bring the dots down.

But as HeyYou said; it doesn't matter if you don't move anything; the dots pointing to each other is to help align everything.

There will be SOME play; the FSM says up to 1/8" deflection with 30 lb/ft applied (heads installed) or 15lb/ft applied (heads off).

RwP
 
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Old 11-09-2018, 01:06 AM
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while your at it, replace front crank seal , water pump (oem), thermostat and small bypass coolant hose
 
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Old 11-14-2018, 12:33 PM
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Originally Posted by HeyYou
That's acceptable.

Generally, folks want to install the gears dot to dot, just puts a different cylinder in firing position. So long as you don't move anything while the gears/chain are off, it's all good.

There was a tensioner available for the V-6 as well, but, it was for use with the morse style chain, I don't recommend them for the double roller, tends to eat the 'slider'.
So you're saying the Cloyes tensioner it's good to use with the double roller? I haven't seen anything from Cloyes about that being a bad combo and in fact I paired their tensioner with a street double roller.

I'm hoping this doesn't result in a problem, isn't most of the wear going to happen on the right side where the chain is under tension?

Interested in hearing more about how this is a bad combo.

Steve
 
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Old 11-16-2018, 09:23 AM
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The morse style chain has a lot more contact area against the tensioner. Double-roller has less than a third of the contact area..... so, it's going to wear faster. Keep in mind, MANY folks have used the tensioner with the double roller chain, and so far, I don't think I have seen anyone report an actual issue. I may just be being too paranoid.
 
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Old 11-16-2018, 10:26 AM
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Originally Posted by HeyYou
I may just be being too paranoid.
Is it paranoia when the universe really IS out to get you?

RwP
 
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Old 11-16-2018, 10:35 AM
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Originally Posted by RalphP
Is it paranoia when the universe really IS out to get you?

RwP
I was afraid of that.........
 
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Old 11-16-2018, 01:54 PM
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I put in a double roller with tensioner 3+ years ago, I have had no problems I know of
 
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Old 11-16-2018, 08:05 PM
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Originally Posted by onemore94dak
I put in a double roller with tensioner 3+ years ago, I have had no problems I know of
I did the same about then; when I had the motor rebuilt this year, I asked them for the old tensioner.

It's not but slightly marked with > 100,000 miles on it; I think the concern is not as critical as some think it is.

It is, however, a CONSIDERATION.

RwP
 


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