DIY Timing chain replacement?
Yes it is difficult and not a job for the weak hearted. There are 3 timing chains, one around the crank and 2 around the cams. I'd wait for someone to chime in exactly what is required for replacement on the 4.7 but I know its a PITA job from what I've heard.
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From: Buffalo, NY
Been there, done that. Ditto on Sharps, comment though. Unless something else is broke, the chains aren't a failure point. Replacement of them requires removal of the intake, water pump, timing cover, harmonic balancer,and all of the attached junk.
Replacement is pretty easy but time consuming and requires a few special (or makeshift) tools.... a special wrench to hold the camshaft sprockets, a harmonic balancer puller (that works for a 4.7) and a couple of pins to hold the tensioner springs in place (I used a couple of pieces of stiff wire).
Do a search on here for it, been documented a few times. Also get the Haynes manual for it before you start.
Bob
Replacement is pretty easy but time consuming and requires a few special (or makeshift) tools.... a special wrench to hold the camshaft sprockets, a harmonic balancer puller (that works for a 4.7) and a couple of pins to hold the tensioner springs in place (I used a couple of pieces of stiff wire).
Do a search on here for it, been documented a few times. Also get the Haynes manual for it before you start.
Bob
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From: Winchester, Kentucky
Been there, done that. Ditto on Sharps, comment though. Unless something else is broke, the chains aren't a failure point. Replacement of them requires removal of the intake, water pump, timing cover, harmonic balancer,and all of the attached junk.
Replacement is pretty easy but time consuming and requires a few special (or makeshift) tools.... a special wrench to hold the camshaft sprockets, a harmonic balancer puller (that works for a 4.7) and a couple of pins to hold the tensioner springs in place (I used a couple of pieces of stiff wire).
Do a search on here for it, been documented a few times. Also get the Haynes manual for it before you start.
Bob
Replacement is pretty easy but time consuming and requires a few special (or makeshift) tools.... a special wrench to hold the camshaft sprockets, a harmonic balancer puller (that works for a 4.7) and a couple of pins to hold the tensioner springs in place (I used a couple of pieces of stiff wire).
Do a search on here for it, been documented a few times. Also get the Haynes manual for it before you start.
Bob
I have a nice intermittent whining noise coming from the front passengers side of the motor behind the AC compressor (best that I can tell). So, I'm guessing timing chain.
Bob (and Shrpshtr),
Pulled the passenger's side valve cover. How much play/distance from the chain guide to the timing chain should there be? Should it be loose or tight? The vehicle has 130,000+ miles, I have read both sides of the discussion about how the chains fail from slugge and how they will last forever. I'm afraid to drive it until I get this figured out in case it is something with the timing chain. (I do have the Haynes Manual.) Also, didn't see a service manual for the 2001 Durango. Is the 2000 or 2002 closer to my year?
Thanks for your help
Mark
Last edited by TennesseeVolsFan; Apr 14, 2011 at 11:13 AM.
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From: Tempe,Az
Have you checked the belt tensioner pulleys i had a whine thought it was the chain pulled the belt and it was the metal pulley
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Joined: Sep 2010
Posts: 396
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From: Buffalo, NY
I doubt that an intermittent whine would be a timing chain. When the tensioners or the guide rails go there is a distinct rattling / slapping sound that the chain(s) make as they hit other parts.
+1 on the belt tensioner pully, it's just below tha AC compressor and will whine when the bearing is gone. Another one to check is the A/C clutch. If the bearing is going on it you'll get a whine when the A/C is *not* engaged.
Water pump, alternator, and power steering are also culprits, however they all usually have more obvious indicators. Still, check them closely.
How old is your belt? If it's the original, or has over 80k on it replace it. Look for knicks in all of the pullys (especially the harmonic balancer) as ity can cause the belt to "wander" off the grooves and make noise.
As far as chain guide distance, that's one that you really need to dissassemble to check fully. Most of the measurements are taken by the thickness of the guides and tensioners, I don't recall an actual spec for "taughtness" of the chain(s). The tensioners themselves are spring loaded and have ratchet pawls on them, so they extend automatically after installation and self adjust outward if needed.
Mileage is all relative on the care of the vehicle. Sludge isn't a factor *UNLESS* the oil wasn't maintained well, or there's been coolant leakage inside the engine. When I pulled mine down (145k+ miles) the head had cracked. The inside of the valve covers and timing chain cover were clean. Recently I changed out the oil pump as well because of (what I thought) a low pressure problem. Turned out to be an intermittent sensor instead. When I pulled the pan I had some mild garbage in a few spots in the pan, but nothing that I wouldnt expect from high mileage.
Give yourself an *honest* assesment of how well the vehicle has been maintained (as long as you've owned it anyways) and make your call from there. One change that I did make based upon suggestions in this forum is to swap over to Mobil 1 full synthetic oil. I don't know if it makes a real difference, but I can tell you for a fact that the engine turns over easier and is quieter on startups in the sub-zero winter nights.
Hope this helps.
Bob
+1 on the belt tensioner pully, it's just below tha AC compressor and will whine when the bearing is gone. Another one to check is the A/C clutch. If the bearing is going on it you'll get a whine when the A/C is *not* engaged.
Water pump, alternator, and power steering are also culprits, however they all usually have more obvious indicators. Still, check them closely.
How old is your belt? If it's the original, or has over 80k on it replace it. Look for knicks in all of the pullys (especially the harmonic balancer) as ity can cause the belt to "wander" off the grooves and make noise.
As far as chain guide distance, that's one that you really need to dissassemble to check fully. Most of the measurements are taken by the thickness of the guides and tensioners, I don't recall an actual spec for "taughtness" of the chain(s). The tensioners themselves are spring loaded and have ratchet pawls on them, so they extend automatically after installation and self adjust outward if needed.
Mileage is all relative on the care of the vehicle. Sludge isn't a factor *UNLESS* the oil wasn't maintained well, or there's been coolant leakage inside the engine. When I pulled mine down (145k+ miles) the head had cracked. The inside of the valve covers and timing chain cover were clean. Recently I changed out the oil pump as well because of (what I thought) a low pressure problem. Turned out to be an intermittent sensor instead. When I pulled the pan I had some mild garbage in a few spots in the pan, but nothing that I wouldnt expect from high mileage.
Give yourself an *honest* assesment of how well the vehicle has been maintained (as long as you've owned it anyways) and make your call from there. One change that I did make based upon suggestions in this forum is to swap over to Mobil 1 full synthetic oil. I don't know if it makes a real difference, but I can tell you for a fact that the engine turns over easier and is quieter on startups in the sub-zero winter nights.
Hope this helps.
Bob
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Registered User
Joined: May 2010
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From: Winchester, Kentucky
I doubt that an intermittent whine would be a timing chain. When the tensioners or the guide rails go there is a distinct rattling / slapping sound that the chain(s) make as they hit other parts.
+1 on the belt tensioner pully, it's just below tha AC compressor and will whine when the bearing is gone. Another one to check is the A/C clutch. If the bearing is going on it you'll get a whine when the A/C is *not* engaged.
Water pump, alternator, and power steering are also culprits, however they all usually have more obvious indicators. Still, check them closely.
How old is your belt? If it's the original, or has over 80k on it replace it. Look for knicks in all of the pullys (especially the harmonic balancer) as ity can cause the belt to "wander" off the grooves and make noise.
As far as chain guide distance, that's one that you really need to dissassemble to check fully. Most of the measurements are taken by the thickness of the guides and tensioners, I don't recall an actual spec for "taughtness" of the chain(s). The tensioners themselves are spring loaded and have ratchet pawls on them, so they extend automatically after installation and self adjust outward if needed.
Mileage is all relative on the care of the vehicle. Sludge isn't a factor *UNLESS* the oil wasn't maintained well, or there's been coolant leakage inside the engine. When I pulled mine down (145k+ miles) the head had cracked. The inside of the valve covers and timing chain cover were clean. Recently I changed out the oil pump as well because of (what I thought) a low pressure problem. Turned out to be an intermittent sensor instead. When I pulled the pan I had some mild garbage in a few spots in the pan, but nothing that I wouldnt expect from high mileage.
Give yourself an *honest* assesment of how well the vehicle has been maintained (as long as you've owned it anyways) and make your call from there. One change that I did make based upon suggestions in this forum is to swap over to Mobil 1 full synthetic oil. I don't know if it makes a real difference, but I can tell you for a fact that the engine turns over easier and is quieter on startups in the sub-zero winter nights.
Hope this helps.
Bob
+1 on the belt tensioner pully, it's just below tha AC compressor and will whine when the bearing is gone. Another one to check is the A/C clutch. If the bearing is going on it you'll get a whine when the A/C is *not* engaged.
Water pump, alternator, and power steering are also culprits, however they all usually have more obvious indicators. Still, check them closely.
How old is your belt? If it's the original, or has over 80k on it replace it. Look for knicks in all of the pullys (especially the harmonic balancer) as ity can cause the belt to "wander" off the grooves and make noise.
As far as chain guide distance, that's one that you really need to dissassemble to check fully. Most of the measurements are taken by the thickness of the guides and tensioners, I don't recall an actual spec for "taughtness" of the chain(s). The tensioners themselves are spring loaded and have ratchet pawls on them, so they extend automatically after installation and self adjust outward if needed.
Mileage is all relative on the care of the vehicle. Sludge isn't a factor *UNLESS* the oil wasn't maintained well, or there's been coolant leakage inside the engine. When I pulled mine down (145k+ miles) the head had cracked. The inside of the valve covers and timing chain cover were clean. Recently I changed out the oil pump as well because of (what I thought) a low pressure problem. Turned out to be an intermittent sensor instead. When I pulled the pan I had some mild garbage in a few spots in the pan, but nothing that I wouldnt expect from high mileage.
Give yourself an *honest* assesment of how well the vehicle has been maintained (as long as you've owned it anyways) and make your call from there. One change that I did make based upon suggestions in this forum is to swap over to Mobil 1 full synthetic oil. I don't know if it makes a real difference, but I can tell you for a fact that the engine turns over easier and is quieter on startups in the sub-zero winter nights.
Hope this helps.
Bob
First, thanks for the response. I truely appreciate the insight. I had considered the tensioner pulleys. However, the sound is distinctly coming from behind the compressor in the neightborhood of the cam sprocket. Also, I failed to mention that at idle, with the intermittent whine, the engine would stumble as well. The guide rail is a good 1/4" away from the chain and the chain has about an 1/8" up and down play. The vehicle did make the slapping sound briefly in the final 50' of pulling it into the garage. I may have caught it right at the point of departure. Does the distances of the chain sound right to you?
Thanks
Mark
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Joined: Sep 2010
Posts: 396
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From: Buffalo, NY
Hmmm.... the distances aren't as important as the tension is. I suppose it's possible that you caught it just as a tensioner started to fail and the chain was slapping up & down, but you won't really be able to see it without pulling the timing cover.
Consider pulling the drivers valve cover as well and compare the tension on that side. Each side has it's own guides & tensioners, so this may give you some more clues.
If they appear the same, then the only other choice is the third chain, but that's completely buried under the timing cover / other chains. You're already well on your way to a rebuild at that point.
Also, remove your serpentine belt and try turning the engine over *BY HAND* with a socket on the crank bolt. If something is gone south you'll hear it.
4.7's are an "interference fit" engine. If a chain jumps or fails, chances are very good that a piston will hit a valve. You should be able to feel resistance while turning teh motor over by hand. Oh yeah, remove the plugs first so you're not fighting compression.
Keep posting what find, there are a bunch of people on here that can all provide good help.
Bob
Consider pulling the drivers valve cover as well and compare the tension on that side. Each side has it's own guides & tensioners, so this may give you some more clues.
If they appear the same, then the only other choice is the third chain, but that's completely buried under the timing cover / other chains. You're already well on your way to a rebuild at that point.
Also, remove your serpentine belt and try turning the engine over *BY HAND* with a socket on the crank bolt. If something is gone south you'll hear it.
4.7's are an "interference fit" engine. If a chain jumps or fails, chances are very good that a piston will hit a valve. You should be able to feel resistance while turning teh motor over by hand. Oh yeah, remove the plugs first so you're not fighting compression.
Keep posting what find, there are a bunch of people on here that can all provide good help.
Bob
