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SOHC: whats this part?

IZwack

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I unbolted the lower half of my SOHC's oil pan today and found this bent metal strip in the pan -- anyone know what this is?

Straightened out, it would be about 2-3/8" long and it is 1/2" in height. There are no part numbers on it and my Explorer ran fine before the pan was removed.

unknown1.jpg
 



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Russ in CT

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That appears to be one of the three metal 'springs' in the Jackshaft chain tensioner (this is the chain that is in the traditional 'timing chain' position on OHV engines). There are three metals strips the same size sandwiched together, which back the plastic tensioner where it rubs on the chain to take up the slack.

When the pastic gets old and brittle, the springs can come loose and fall into the pan. The two dangers here are they plug up the oil intake and can lead to oil starvation, and the jackshaft chain can skip a tooth leading to valve timing issues, potentially valve to piston collision (this is an 'interference' engine). Either of these of course is catastrophic engine damage.

Since you found one, there are two more that are probably ready to fall out as well.

There is a TSB from Ford on this. I'll try and look up the TSB # and a photo of the jackshaft chain, etc, and post in a follow up reply.

The TSB talks about a 'pinging' sound between 2K-3K rpm's. I had this issue, and it indeed sounded very much like pinging.

You'll want to get this fixed ASAP, however it not cheap. You may also want to consider replacing the front timing chain cassette (the chain, gears & guide) at this time as well, since it would already be apart (the Jackshaft chain connects crank to jackshaft, shaft that sits where an OHV camshaft would be, but in this engine is just a 'dummy' shaft to drive the SOHC drives. Then there is a front camshaft chain that connects jackshaft to drivers side cam, and a rear camshaft chain, jackshaft to passenger cam). Also the front & rear timing chain tensioners are an external screw in deal, looks like a large, black bolt in the side of the head, might want to do these as well.
 






Russ in CT

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Forgot to mention there is another tensioner inside these engines that have a very similar metal strip sandwich tensioner, the balance shaft chain tensioner (if you have 4x4, if not, you don't have a balance shaft, for whatever reason Ford decided non-4x4 models could have more vibs).

However the balance chain is not as wide as the jackshaft chain, hence the plastic part that pushes on the chain, and the metal springs, are not as wide. From your description (1/2" wide) I'd say your metal strip is from the jackshaft tensioner.

Note the balance tensioner has only two metal springs. They are a little shorter and a little narrower than the springs in the jackshaft tensioner.
 






IZwack

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Hey thanks for the replies Russ in CT.

I was afraid its the timing chain doodad I've heard so often about. But there is no way of telling which cassette it came from right?

I did plan to do the 00m12 fix -- will this kit fix the issue?
 






Russ in CT

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Here is a photo of the offending jackshaft chain tensioner. Tensioner is on the left of the jackshaft chain, guide is on the right. The part of the tensioner that presses against the chain is backed by the three metal strips.
 

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Russ in CT

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...and here is a closeup detailing the metal strip sandwich. Note the broken plastic ready to let go and allow some of these strips to fall into the pan.

Also, note that in the previous photo (last post above), you can see the front cam chain referred to earlier. There is a gear behind the top jackshaft gear (the bottom cam chain gear), then above the head on the right you can see the other end (top) of the cam chain.
 

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Russ in CT

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The TSB is 02-7-6. Details below.

Also there is a notice regarding the front tensioner, its 01M01 and 00M12. this notice states its related to an cold idle issue, but it turns out Ford combined the front tensioner notice with this one about idle issues since they were found around the same time and you had to remove all the same intake manifold stuff for both, and the parts were cheap, labor was not. Made sense to always do both together regardless of symptoms.

TSB 02-7-6:

*Engine - 4.0L SOHC - Rattle noise from primary chain drive area between 2K-3K RPM - Cold engine operation only

*Noise - Rattle noise from primary timing chain drive area between 2K-3K RPM - Cold engine operation only - vehicles equipped with 4.0L SOHC Engine only

Ford: 99-02 Explorer, 01-02 Sport Trac, Explorer Sport, Ranger
Mercury: 99-02 Mountaineer

Issue:

Some vehicles equipped with the 4.0 SOHC (Single Over-Head Cam) engine may exhibit a Primary Timing Chain rattle noise. The noise is audible during hot and cold engine operation (but predominantly found on cold engines) under acceleration, typically at 2400-2500 rpm. To confirm presence of this noise, accelerate in 2nd gear between 2000-3000 rpm and listen for rattle noise that sounds similar to spark knock. This may be caused by the Primary Timing Chain Tensioner system.

Action:

Replace the Primary Timing Chain Tensioner, Chain Guide, Jackshaft, and Crankshaft Sprockets with a Primary Timing Chain Tensioner Kit. The kit includes an improved Primary Chain Tensioner, as well as updated Primary Chain Guide, Jackshaft, and Crankshaft Sprockets. Required fastners, primary timing chain, and front cover gaskets are also included. Refer to the following Service Procedure for details.

Service Procedure:

Verify the condition. Obtain the correct kit and follow the sheet supplied with the kit.

Use kit 2U3Z-6D256-AA (balance shaft engines) for:
-99-01 4x4 Explorer/Mountaineer
-01-02 4x4 Sport/Sport Trac
-All 02 Explorer/Mountaineer, except engine codes 2G-960-AA and 2G-964-AA

Use kit 2U3Z-6D256-BA (non blance shaft engines) for:
-99-01 4x2 Explorer/Mountaineer
-01-02 4x2 Sport/Sport Trac
-02 Explorer/Mountaineer with engine codes 2G-960-AA and 2G-964-AA
-All 2001-02 Ranger

Labor Time: Estimated around 6 hours

Warranty Status: Elgible under the provisions of Bumper to Bumper warranty coverage
 






Russ in CT

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One last thing, if you're going to have this repair done very soon, I could really use your old parts. Need to sue my repair shop (long story), and I need an example of a jackshaft tensioner to complare my busted parts with, and I'm too cheap to buy another new one.
 






IZwack

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Thanks for all the info Russ in CT.

Use kit 2U3Z-6D256-AA (balance shaft engines) for:
-99-01 4x4 Explorer/Mountaineer
-01-02 4x4 Sport/Sport Trac
-All 02 Explorer/Mountaineer, except engine codes 2G-960-AA and 2G-964-AA
I'm assuming the part numbers are the same for the '98 engine?


And as for the old parts, yep you can have them. I'll shoot you a PM once I'm finished installing the kit -- hopefully in a week or week and a half.
 






Russ in CT

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i THINK the parts are the same for '98. The dealer should be able to tell you when you order (they gotta be good for SOMETHING).

Note that to do this job you gotta have the timing alignment tools. They are several hundred bucks online (sometimes on eBay too). You can resell them when you are done, hopefully at not too much loss.

None of the timing gears have any keys or alignment marks, the timing is is set be aligning with these tools then locked down when you tighten it all up.

If you don't have the tools in place, DO NOT disassemble any of the timing chain stuff.

Also, inspect the balance tensioner (if you have one) while you have it apart. It sits down in the upper pan (AKA Ladder Frame), but you can get a good enough look at it to see if its intact (suffers from same plastic breakage and spring falling out as jackshaft tensioner). If it needs to be replaced, you need to remove the Ladder Frame. You CAN do this by dropping front axle (not as bad as it sounds), then remove motor mount bolts (accessible via fender well, remove splash shield). Jack up motor a bit, and you can get the Ladder Frame off, barely.

Note you need some torx bits and some star sockets (inverse of torx) to do this job.

My engine was high mileage. If I had to do this over again I would have just bought a used, low mileage motor and swapped.
 






IZwack

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Note that to do this job you gotta have the timing alignment tools. They are several hundred bucks online (sometimes on eBay too). You can resell them when you are done, hopefully at not too much loss.
I read a few tid bits about this tool, but can't you just mark the two timing sprockets before dissasembly? Or maybe prevent the sprockets from turning (i'll tack weld a piece of steel on it if i have to ;))
 






Russ in CT

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I did read on here about somebody doing something similar, and it apparently worked for them.

But the tools don't just hold the parts in place, they allow you to retime the engine. If this corrects your timing even slightly, the additional power gains and fuel cost savings might make it worth it to get the tools.
 






IZwack

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So the goal is to prevent the two sprockets from rotating? I dont mind if the timing is off by a little bit, my vehicle is illegal to drive on the streets and is for trails only. But to verify that the timing isnt too terribly off, can I not rotate the crankshaft with a socket a few times and hope that no valves will run into a piston?

And I called the local Ford dealership and they quoted me $220 and some change for both the front and back kit -- sounds good?
 






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So the goal is to prevent the two sprockets from rotating? I dont mind if the timing is off by a little bit, my vehicle is illegal to drive on the streets and is for trails only. But to verify that the timing isnt too terribly off, can I not rotate the crankshaft with a socket and hope that no valves will run into a piston?

And I called the local Ford dealership and they quoted me $220 and some change for both the front and back kit -- sounds good?

Try contacting Spas about the parts.. I think her prices are a little better :p
 






CDW6212R

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Pull the part numbers from the few good threads here, then go to the good Ford parts sites to buy them. Skip the rear cam cassette($60), get the rear cam tensioner($25) and front chains/guides, tensioners.

Don't bypass the tools, each head and the crank assembly are tied together through the center jackshaft. If the jackshaft bolt is loosened, each head can and likely would want to move away from where it is. The parts connect by no splines or teeth. The end cam bolts and the jackshaft bolt all hold the shafts to the gears there with crush pressure. There is infinite possible alignment at each of those shafts.

The TDC tools point the crank to TDC, and hold one camshaft at TDC, while another tool encloses the cam bolt for loosening and tightening. Each cam is timed separately with the crank with the TDC tools. It's a pain and time consuming, but the tools can be had for under $150 often. Hunt the tool as soon as possible.

BTW, note the first engine picture above. That is my engine after I installed the parts the first time. The crank gear is on backwards there, the tiny dots on the gear go on the back. The concave side of the crank gear faces forward, to accept the balancer end. Regards,
 






IZwack

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Thanks for chimming in CDW6212R.

Can someone please verify that the timing tool set is not required to do the front?

If this is true, then I'm first going to do the 00m12 kit for now -- hopefully when I dig into the front, one of the cassettes there will be missing one of its little metal band. I can always do the back in the future and I will fabricate the firewall/tunnel to allow easy access to the back of the engine. Also, my vehicle moves maybe 70 miles or so a year max since its a trailer queen.

On the other hand, if the front cassettes still have all of their metal bands intact, then I will obviously go on to doing the back.
 






CDW6212R

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If you only do that small TSB first, you will not see the jackshaft and other front parts. That kit has only the upper intake coming off, to access the screw in tensioner for the front camshaft chain. I wouldn't drive that truck any significant period before doing the work. I doubt that the tensioner that is damaged here will work well for very long. Good luck,
 






IZwack

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Yeah you're right -- I'm probably just going to just do the whole thing while the engine is still where it is and I'll have clear access to the back after part of the firewall has been removed. Does the transmission have to come off to do the rear?

SOHC = :confused:
That small-block Chevy swap looks more and more enticing -- all sorts of fancy transmissions with minimum gears, delicious gear-driven transfer cases and so on .. but of course v8's are longer :(
 






CDW6212R

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Unless you have a big symptom from the rear, or high miles, I'd do like others and skip the rear cassette until you need to pull the engine or trans. The parts in the back are basically just like those in the front, minus the crank to jackshaft chain. You need to remove a cover(plug) over the jackshaft etc.

I'm looking at making an electric fan for my 302 right now, there is very little room there in front. BTW, the 302 is a bunch smaller than any Chevy small block, at 8.2 deck height while the Chevy is 9 inches. Night,
 



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IZwack

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I'm looking at making an electric fan for my 302 right now, there is very little room there in front.
Thanks for the info again.

I dunno if you already know this but apparently the Taurus and Mark-7/8 (and the likes from Mercury) fans are some of the most powerful electric fans you can find out there. They blow at a significantly greater CFM than almost all aftermarket electric fans available (say from Summit). A majority of the home-brewed rock buggies out there use this fan.
 






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