4.0 sohc timing chain rattle - everything you need to know
 

Seen many, many many many posts on here about the 4.0 sohc timing chain rattle, so here is literally everything you need to know about it.

I have recently rebuilt the top end of my 4.0, so do not hesitate to ask me questions on this thread or via PM if you can not find an answer looking through all of the following:

Im not posting a how to as there are many links about causes/diagnosis/repairs scattered throughout the internet. Here I am going to post about every link known to man about how to deal with the infamous SOHC rattle.

First off: THE FAULTY TIMING CHAIN TENSIONERS WERE FOUND ANYWHERE BETWEEN 2001~2004, AFTER THAT, FORD USED THE UPDATED HARDWARE. THAT STILL DOES NOT MEAN YOUR 2005+ 4.0 WONT DEVELOP PROBLEMS. ALL 4.0 SOHC OWNERS SHOULD REPLACE THE PLUNGER TYPE SCREW-IN TENSIONERS EVERY 70,000 MILES OR SO TO PREVENT CHAIN SLACK, WHICH KILLS THE GUIDES!

If the rattle is ONLY on startup, and never at idle, or at any other RPMS's it is most likely the tensioners. They screw into the block and are ~$80 from ford. Much better than having to possibly remove the engine to replace all of the guides.

They look like this:

http://i.ebayimg.com/images/i/201397...-1/s-l1000.jpg

If that does not solve the problem, look here:

If you hear the rattle coming from the front of the engine, it is MOST LIKELY coming from the primary cassette/tensioner (the chain that connects the crank to the jackshaft and drivers side cylinder head)

Here is a picture of one that is fubar:

http://www.explorerforum.com/forums/...chmentid=60234

Here is one that has been corrected using the updated componets:

https://lh3.googleusercontent.com/-d...9-VgP07pen-e3w

If this is your problem, then you DO NOT HAVE TO REMOVE THE ENGINE!! all you have to do is pull the front timing cover as you would with a pushrod engine. Also, if the drivers side guide is broken, you can replace it with the engine in as well.

Now, if the rattling is coming from the rear passenger side, you'll either have to remove the engine or transmission in order to replace the chain and guide set, HOWEVER it IS possible to replace the rear GUIDE without removing the engine. Note, guide only. To remove as well the chain you have to at LEAST remove the transmission in order to pop off the rear jackshaft sprocket cover in order to remove the bolt holding on the sprocket. The ford OTC-6488 tool is designed so that you can remove the rear cam sprocket, replace the guide, and re-time the cams with the engine in the vehicle, remind you, it'll be cramped, but it is possible. In fact, using alldata, the service procedure has you replace the rear guide with the engine in. There have been people who have successfully replaced the rear guide with the engine in.

Now, here are links to all of the SOHC replacement threads. I highly recommend using a database like all data, or a Haynes or factory ford service manual along with these links. A lot of these links are for 4.0 explorers, but the process is essentially the same, however, use ranger 4.0 torque specs as the explorers have had two types of 4.0's in them; Job 1's with the aluminum valve covers, and the Job 2 explorer 4.0s which were similar to the 2001+ ranger 4.0's, so be careful when you search torque specs. To play it safe, use alldata or a service manual.

timing chain replacement walktrhough PDF:

http://sohcreplace.blogspot.com/2008...97-2005-4.html

Links to SOHC timing chain related threads, search through all of them until you find what you need:

http://www.explorerforum.com/forums/...d.php?t=278100

http://www.explorerforum.com/forums/...d.php?t=316471

http://www.explorerforum.com/forums/...d.php?t=287416

http://www.explorerforum.com/forums/...d.php?t=269442

This guy has many videos on replacement of the 4.0 SOHC timing
chain/guides/tensioners. Here is the link to his youtube channel. with a
long list of videos on how he did it.

https://www.youtube.com/user/cruzroy...y=timing+chain

4.0 SOHC TIMING CHAIN PART NUMBERS

Jackshaft/primary timing chain kit 2U3Z6D256CA includes:
Crankshaft bolt harmonic balancer E7RY6A340B
Tensioner-engine jackshaft chain YL2Z6L266AA
Gasket-cylinder/timing front cover F77Z6020AB superseded by 1L2Z6020AA
Sprocket/gear-engine jackshaft/intermediate 2U3Z6M264AA
Guide-engine jackshaft chain 2L2Z6K297AA
Bolt-jackshaft sprocket bolt F77Z6M264BA superseded by 2L2Z6279AA (included when 2U3Z6M264AA is purchased)
Sprocket/gear-crankshaft two wheel drive 2L2Z6306BA
Chain-engine jackshaft F77Z6268AB
Bolt-camshaft sprocket right hand
Bolt-camshaft sprocket left hand F77Z6279BA

Left/front timing chain cassette assembly 7U3Z6A257A includes:
Timing chain
Guide assembly YL2Z6M273AA superseded by 7U3Z6A257A
Bolt-guide assembly upper mount
Sprocket/gear-camshaft
Sprocket/gear-jackshaft front

Right/rear timing chain cassette assembly 4L2Z6M290AA includes:
Timing chain
Guide assembly
Sprocket/gear-camshaft
Sprocket/gear-jackshaft rear

Intake manifold gaskets: 1L2Z-9461-CA

Left timing chain tensioner 7U3Z6K254B

Tensioner metal O ring XU2Z6M252AA

Right timing chain tensioner 7U3Z6K254A supersedes XU3Z6K254BA

Right timing chain guide assembly upper positioning bolt F77Z6U000BA

Jackshaft rear sprocket retaining bolt W703167S430

Cover assy/rear of block jackshaft opening plug F77Z6026AB

Left cassette assembly lower mounting bolt W500100S300

Jackshaft chain guide mounting bolt W500100S300

Sprocket/gear-crankshaft inner four wheel drive F77Z6306BE

Sprocket/gear - crankshaft outer four wheel drive 2L2Z6306AA

Balance shaft chain guide F77Z6K297BC

Balance shaft chain tensioner 1L2Z6L266AA

Balance shaft chain F77Z6268BC

Balance shaft assembly 1L2Z6A311AA

Seal-front timing cover E6TZ6700A was superseded by 5H2Z6700AA

Seal-rear main crankshaft F5TZ6701A

Gasket set-valve cover F77Z6584AE

Gasket-lower oil pan 4L2Z6710AA year 2000+ F77Z6710BA year 1997-1999

Gasket-upper oil pan/reinforcement section F77Z6710AA

Block cradle retaining bolt seal F77Z-6734-AB (Listed as engine oil drain plug gasket)

Left camshaft F7TZ6250AEE was superseded by 7L2Z6250D

Right camshaft F77Z6250AE

Exhaust manifold outlet bolts (M12-1.75X54.5 H) N811747S2

*NOTE: I am not responsible for damages done to your vehicle, repair at your own risk*

Re: 4.0 sohc timing chain rattle - everything you need to know
 

Great Info - Thanks for gathering it all together!

Thanks!

X2 very nice write up, I have a video of when I changed my tensioners, the top one was tricky. Saving this in my favorites lol.

The plunger type? The one on the drivers side you have to remove the thermostat housing to take it out.

Yea that one was a pain, trying to push, turn and not crossthread at the same time lol

----------


We cut one of the old tensioners and used it as a thread chaser.

Very carefully is an understatement, hahah

Lol as the video goes on you can see we went until night. As you may know working on a vehicle+4 FRF buddies = endless bs time....which is why it took so long haha.

Re: 4.0 sohc timing chain rattle - everything you need to know
 

Noticed Rattle on startup at 148,000 2002 Ford Edge V6 4.0L.
Checked round and found out about Primary Timing Chain rattle noise. Took vehicle to Ford dealership. They knew what it was without me talking about it. They wanted $4K to tear down and put in new tensioner with no guarantee. $6K for remanufactured engine with minimal guarantee. I was extremely disappointed to say the least.
Engine froze up on the way home and had vehicle towed.

This has priced me out of repairing a mint condition vehicle except for the Ford flaw. This is a money generating flaw by Ford. All with no help to the customer. Have several friends who used to own Rangers and Escapes/Mariners. They had these problems in the 90's and recently, but, did not know what the real problem was. They all have walked away from Fords entirely forever and now own foreign vehicles.
I wanted to stay with American trucks, however, I cannot afford to keep taking huge financial hits with Ford products.

I don't think it was a money generating product for ford more so a first couple years design bug. Like stated in the original post ford had redesigned this system in 2003-2004. But the system itself, no matter how well engineered, will fail if you do not replace the exterior timing chain tensioners every 70k. Ford made it easy on us by putting the tensioners on the outside of the heads so they can be changed easily. People just aren't informed about the tensioners needing to be replaced until it's too late. This is the reason I created this thread is to help people with the timing chain noise, in hopes of preventing engine damage. I know of many people who have replace the external tensioners before it was too late and that alone solved the problem.

Re: 4.0 sohc timing chain rattle - everything you need to know
 

I have a 2001 Ford Ranger 4.0 SOHC with 159,000 miles. Approximately 7-8 thousand miles ago I began having a rattle as my truck would upshift between 2.5 and 3k RPM. I didn't make much of it and at the time was unaware of this issue. The rattle has progressed and will occur during acceleration from 2.5k RPM and up. Also, it makes a very brief but load rattle on cold starts. I have noticed that the noise which occurs while driving is not there when the engine is still warming up just after I leave my house. I haven't been able to isolate the location of the rattle so I am unsure which tensioners are causing the issue. Based off of the description I gave can you make any guesses?

It could be any of them but as it isn't only on startup it is most likely a broken guide. The first to go is usually the primary chain from the crank to the jacks haft. But I'd pull both valve covers as well as the front cover to be sure.

Gonna try and tackle replacing the pre-tensioners. I've come across some conflicting information though. Do you need to "prime" them with oil before install? I've read that you need to and also that it's not necessary. My understanding of how the tensioner works is that the spring holds tension in the chain until hydraulic pressure from the oil can maintain tension. So it would make sense that you wouldn't need to prime them. But, I've been wrong before, so I figured I'd better ask.

Anybody?

Re: 4.0 sohc timing chain rattle - everything you need to know
 

tensioners should of been replaced at 70000 miles. at least one of your guides is gone. 2001 had weak guide design. front of motor guide most likely. will have to pull timing chain cover to check.