How to replace a 3.7L or 4.7L timing chain(s) and/or components from 2002-2007 for Dodge & Jeep

The vehicle on display is a 2003 Dodge R1500 w/ a 4.7L.  I assume that if you’re tackling timing chains and/or components on either the 3.7L or 4.7L you are more than capable of removing aforementioned items without me walking you through them with pictures:  disconnect the negative battery cable, drain cooling system, remove the right and left cylinder head covers, remove the radiator fan shroud, remove fan and fan drive assembly, disconnect both heater hoses at the timing cover, disconnect lower radiator hose at the engine, remove accessory drive belt tensioner assembly, remove the generator, remove the AC compressor (lay off to the side), remove the power steering pump (lay off to the side), remove oil filler plastic housing, and remove access plugs from the left and right cylinder heads for access to chain guide fasteners (shown in pic below).


 

 

 

At this point, go ahead and remove the camshaft position sensor with location shown in pic above along with the water pump.


 

 

 

By now, this should be what the face of your engine looks like.  Next, rotate the engine using the crankshaft bolt until the timing mark on the crankshaft damper aligns with the TDC mark on the timing chain cover and the camshaft sprocket “V8” marks are at the 12 o’clock position.


 

 

 

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Remove the crankshaft damper bolt (usually have to slightly readjust crankshaft pulley afterward) and crankshaft damper using a damper puller and then remove the timing chain cover assembly.  The pic below shows the bolt and stud locations.  I would encourage you to take a piece of cardboard, and stick the bolts and studs through it in the design you remove them.


 

 

 

After removing all the timing cover bolts and studs, remove any remaining gasket and/or adhesive from the cover and engine block face being very careful not to allow anything to fall into the oil pan.  Below are various pictures without the timing cover just for reference points if you need them.

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Next, collapse and pin the primary chain tensioner using adjustable pliers as shown in the picture and remove the primary chain tensioner.  Next, remove the secondary chain tensioners and remove the camshaft position sensor from the right cylinder head.

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Once all the chain tensioners are removed, you’ll need to remove the left and right camshaft sprocket bolts.  Once removed, hold the left camshaft steel tube with adjustable pliers and remove the left camshaft sprocket.  Be CAREFUL to slowly rotate the left camshaft approximately 15 degrees clockwise to a neutral position before releasing camshaft.  Likewise, while holding the right camshaft steel tube with adjustable pliers, remove the right camshaft sprocket.   Be CAREFUL to slowly rotate the right camshaft approximately 45 degrees counterclockwise to a neutral position before releasing camshaft.

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At this point, remove the idler sprocket assembly bolt, and then slide the idler sprocket assembly and crank sprocket forward simultaneously to remove the primary and secondary chains.  After you’ve removed all the chains, remove the tensioner arms and chain guides.

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Since our timing chain kit comes with all of the timing chain components, I’ve not taken the time to compress the secondary timing chain tensioners, but, if for some reason you need to, you can use a vise to lightly compress the secondary chain tensioner piston until the piston step is flush with the tensioner body and then place a lock pin (heavy paperclip may work) into the hole on the front of the tensioner.

 

 

 


 

Now on to the fun of putting it all back together with the new parts.  The kit we’re installing is a Cloyes Timing Chain Kit which comes with new camshaft, idler, and crankshaft sprockets, tensioners, chains, guides, and tensioner arms.  Do to the high mileage of this vehicle and the “special” noises coming from the timing chain area, we opted to replace all timing chain components.  IF, for some reason, you are going to replace the secondary chains, ALWAYS replace the primary chain at the same time.  Go ahead and thoroughly clean your valve covers, tops of cylinder heads, timing cover (REMEMBER to replace the crankshaft oil seal in the timing cover), and face of the engine block.

Before installing anything back on the engine, make sure to verify that all the sprockets are identical to the original sprockets they are replacing.  We had to make one slight adjustment on ours, and then lubed the inside metal surfaces to make installation simpler.

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Position the primary chain tensioner over the oil pump and insert bolts into lower two holes on tensioner bracket.  Tighten the bolts to 250 in. lbs.  Next, install the right side chain tensioner arm – remember to apply Mopar Lock N Seal or equivalent to the torx bolt and then tighten to 150 in. lbs.

Install the left side chain guide and tighten the bolts to 250 in. lbs.  Then, install the left side chain tensioner arm – remember to apply Mopar Lock N Seal or equivalent to the torx bolt and then tighten to 150 in. lbs.

Install the right side chain guide and tighten the bolts to 250 in. lbs.  Next, install both secondary chains onto the idler sprocket.  Align two plated links on the secondary chains to be visible through the two lower openings on the idler sprocket (these should be at the positions of 4 o’clock and 8 o’clock).  Once the secondary timing chains are installed, position special tool 8515 (you can purchase it through OTC, Miller, Mopar, etc.) to hold the chains in place for installation.  You can see in the pictures below that I painted some of the black, plated links on the new chains yellow as this makes it easier to see during installation.


 

 

 

 

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At this point, align the primary chain double plated links with the timing mark at 12 o’clock on the idler sprocket, and align the primary chain single plated link with the timing mark at 6 o’clock on the crankshaft sprocket.


 

 

 

Install all chains, crankshaft sprocket, and idler sprocket as an assembly as shown below.  You’ll have to guide both secondary chains through the block and cylinder head openings.  Once the secondary chains are pulled through the openings to the tops of the cylinder heads, hook a  bungee cord or coat hanger to them to maintain tension and keep them from falling back down through the opening.

 

 

 

 

 

Due to having to allow the camshafts to slightly rotate to a neutral position when taking off the camshaft sprockets during disassembly, you will need to slightly rotate each camshaft back to its original position (and hold it there) before installing the new sprockets.  Align the left camshaft sprocket “L” dot to the plated link on the chain.  Then, align the right camshaft sprocket “R” dot to the plated link on the chain.  Remove the special tool 8515, then attach both sprockets to the camshafts and finger tighten both bolts.  Verify that all the plated links are aligned with the marks on all the sprockets, and “V8” marks on the camshaft sprockets are at the 12 o’clock position.


 

 

 

Install both secondary chain tensioners and tighten the bolts to 250 in. lbs.  REMEMBER to make sure the plate between the left secondary chain tensioner and the block is correctly installed.  Install the idler sprocket bolt, REMEMBERING to lubricate the washer with oil, and tightened the idler sprocket retaining bolt to 25 ft. lbs.  At this point, remove all three locking pins from the tensioners.

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Using special tool 6958 Spanner Wrench with the 8346 Adapter Pins (you have to buy them separately as they do NOT come with the spanner wrench), tighten the left and right camshaft sprocket bolts to 90 ft. lbs.


 

 

 

 

Squirt, or pour, engine oil on all the chains/guides.  Rotate the engine 2 full revolutions and verify the timing marks are still correct.


 

 

 

Since we already cleaned our valve covers and mating surfaces earlier in the procedure, re-wipe them one more time to ensure they are clean and re-install them with new gaskets – I prefer to add a little bit of gasket maker around coolant ports and engine and/or cylinder head metal contour changes.
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REMEMBER to tighten the timing cover bolts/studs in the order shown above to 40 ft. lbs.

Continue re-assembling the engine components in the opposite order you removed them.  REMEMBER to coat the large threaded access plug with thread sealant before installing it into the right cylinder head, and tighten to 60 ft. lbs.  Word of WISDOM, make sure to change the engine oil and filter before starting it up.  Congratulations on what you accomplished!!!

 

 

15 thoughts on “How to replace a 3.7L or 4.7L timing chain(s) and/or components from 2002-2007 for Dodge & Jeep

  1. I Like the description but nobody is saying which stroke to start on now I have no idea which 1 I am because I pulled both heads off I’ve done in exactly what you showed on yours but I still have no fire strong fuel and I don’t know if my timing’s off or what

  2. Hi there, great guide!
    I overhauled my heads recently and now I have to change my timing chain.

    Would you say that it´s essential to use the special tool 8515 or could one do it whithout this tool?

    This will surely be my manual when replacing the timing chain. 🙂

    Regards
    Øyvind from Norway

    • Hey bud! Tool 8515 is used to hold the camshaft secondary chains in place on the idler sprocket when setting up the timing. Definitely a must have when replacing the timing chains on the 3.7L & 4.7L engines.

  3. I have watched several Youtube videos on this and your written description with photos is the best I have seen.

  4. Not doing entire timing chains, just trying to fix coolant leak in timing cover….only gasket kit I found has only O-rings, and rtv sealant…but no place to seat the o-rings as it is flat metal to metal…can’t seem to find anything on this anywhere?

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