How to: - SOHC V6 Timing Chain Parts Removal Procedure | Page 3 | Ford Explorer Forums - Serious Explorations

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How to: SOHC V6 Timing Chain Parts Removal Procedure

Prefix for threads which are instructional.
primary cassette?

. . . i am trying to remove the primary cassette. and i noticed above you said it takes an EXTERNAL E-30 socket. i cannot seem to find this socket, i was wondering if you could tell me where you bought this socket or if you have a link or if you even would like to sell it. i am stuck at this part and cannot find the correct external socket size to remove the primary chain. . .

I'm not sure what you mean by "the primary cassette". The primary chain is the chain between the crankshaft and the jackshaft. The primary tensioner and guide are the ones associated with that chain. The cassettes are either for the left camshaft or the right camshaft. I can't find the reference to "an External E-30 socket" you mentioned above. I remember that an external torx socket is needed to remove the flexplate to crankshaft bolts and the jackshaft front sprocket retaining bolt but all other timing related sockets are Torx internal. The T-30 is needed for the cassette positioning bolts and can be purchased at most auto parts stores (Auto Zone, Advance Auto, O' Reilly, etc. or Harbor Freight star-bit-set).

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jackshaft front sprocket?

If you're trying to remove the jackshaft front sprocket I think the retaining bolt takes an E-18 socket e-socket-set. Be advised that it is not necessary to remove the jackshaft front sprocket to replace the primary chain tensioner or guide. If you do remove the sprocket or loosen the sprocket retaining bolt you will have to retime the left and right camshaft which normally requires use of the OTC-6488 timing tool kit.

I am only replacing the left cam guide/tensioner as well as the jackshaft guide/tensioner (but thats the easy part). Ive already done the front and rear hydraulic tensioners and it didnt help much so Im assuming some guides are broken.

Here is my only issue before I begin. I am trying to complete this job without the OTC tool.
So..heres my thinking.

As long as I keep the left cam chain taught (I was thinking of using zip ties) and mark the cam sprocket and camshaft with a scratch awl, when I torque the bolt down, wont the washer allow the cam sprocket bolt to spin until its properly torqued or is this not true? I realize TDC much first be obtained before the loosening/tightening of the cam bolt. Shouldnt I be good as long as my lines stay matched up?

Also I was thinking I could remove the left cassette guide by just removing the upper sprocket and leave the cam chain in (slacked of course so it wont fall off the bottom sprocket). Will the chain get in the way when I try to remove the guide? Thanks for all your posts on this matter. Its given me the confidence to do it myself.


pull the valve covers and check

I suggest that you pull off the valve covers and check for broken guide assemblies. If the right one is broken then you'll have to remove the engine to replace it. Look at this thread: SOHC V6 Timing Chain Inspection & Repair

Some members have been unable to remove the left guide assembly lower positioning bolt without removing the front jackshaft sprocket. At some point Ford changed the jackshaft sprocket and the bolt head will not pass thru the sprocket hole. If you loosen the front jackshaft sprocket retaining bolt the right bank compressed valve springs will rotate the jackshaft and timing will be lost.

If you loosen the front jackshaft sprocket retaining bolt the right bank compressed valve springs will rotate the jackshaft and timing will be lost.

Is the Jackshaft sprocket keyed onto the jackshaft? I ask because I want to utilize an improvised tool to hold the jackshaft from turning and on your writeup you mentioned (without otc tool) that one could utilize a chain to hold the jackshaft.

Which brings me to my next question. How does holding the sprocket from turning (by way of chain, etc.), hold the jackshaft if the sprocket isnt keyed? I think Im missing something here. Once that bolt is loose, wouldnt the jackshaft spin independently of the sprocket?

Edit: I think I figured it out. The chain is only to hold the crank/jack shaft in order to release the bolt and not used to hold the jackshaft from spinning. So without the OTC holding the right bank cam, how could one replace the left cassette without using the otc cam holding tool? Thats actually what Im not understanding.

jackshaft not keyed

Is the Jackshaft sprocket keyed onto the jackshaft? . . .
Neither the front nor rear sprockets on the jackshaft are keyed. They are kept in position entirely by the tension of the torqued sprocket retaining bolts. That's why if you loosen either jackshaft sprocket retaining bolt the timing relative to the crankshaft will be lost.
. . . So without the OTC holding the right bank cam, how could one replace the left cassette without using the otc cam holding tool? Thats actually what Im not understanding.
Your 98 model probably has the older front jackshaft sprocket allowing removal of the left guide assembly lower positioning bolt without loosening the jackshaft front sprocket retaining bolt. Read the thread I referenced. Or, you can remove the front jackshaft sprocket, replace the left cassette and then retime the camshafts. I timed my camshafts without using the tool kit. However, it was much easier to do with the engine out of the vehicle.

I still suggest that you determine what has failed before replacing components. If the rear cassette is bad then the engine has to come out and then everything can be repaired much easier.

Well I took a looksie and the rear appears to be in tact from what I can see. There isnt much room back there with the hood in the way. I replaced the rear hydraulic tensioner last year as well. All of the noise is coming from the front and main chains. And the noise is intermittent. Sometimes I cant even hear it. On start ups it sometimes slaps but not that bad. Ive been driving around on borrowed time thats for sure.

So I went ahead and purchased the left cam guide and jackshaft guide/tensioner and will be replacing those. If the rear goes out, then Im scrapping the vehicle, its as simple as that. I dont have the means to take the engine out. If I do this repair and the rear fails....then it fails. No worries as I havent dumped too much cash into this so far. I will unfortunately have to write it off as a loss and move on. Ive had the beast since she was brand new so if she wants to break on me after this repair, its been a good ride. :)

So anyways, I think I will go with the idea of clamping something underneath the bearing caps. Looks like a few guys have had luck doing that. I just have to figure out how to lock the crank in place before I tighten that cam sprocket bolt - or would locking the cams in place be enough to hold the crank from turning? Id imagine the crank would turn even if the cams were locked. 63 lb-ft is quite a bit of force Id say.

Im trying to think of how I can lock the crank down, but no idea yet. I will have to get creative without the otc tool set. The ratchet strap idea seems like it would work. And hopefully luck will be on my side so I dont have to remove the jackshaft bolt. Im gonna tear into her this weekend and get started. Thanks for taking your time to reply.

no balance shaft

Since you have 2WD you won't have the balance shaft tensioner and guide to worry about. Often they fail and produce chain rattle.

For the right guide assembly reach down with your fingers and pull up on it and then push it sideways. If it moves significantly then its broken. Make sure the top end of the guide isn't missing.

I used plastic strips to hold my camshaft in place (SOHC V6 Timing Chain Saga) but I don't recommend that method. If the camshaft bearing caps are not carefully removed and installed they can jam and break. It happened to one forum member and was a real pain to resolve. The bearings are not inserts and are machined surfaces in the caps and heads. Several members have used multiple locking pliers to hold the camshafts and I think this is a better method. Just make sure they're not applied to the camshaft lobes.

Hey guys, i'm new to this forum and in need of some help.
Firstly, this thread is fantastic and thank you for the effort that you've put into showing the job at hand!
My dilema is that I live in Australia and own a Ford Courier PH which has the same v6 4.0 SOHC borrowed from the Explorer. needless to say, the timing chain rattle has recently become an issue for myself and i am now looking to undertake the repair job on it. Iv confirmed with Ford Australia that the parts are the same codes as the Explorer and mostly the job should be almost identical, other then some minor things with pulling the block out I imagine.
I was wondering if you had put a list together of all tools/ parts required for the job. Any and all info will be greatly appreciated as i plan to replace all wearable items as I go but need to try and have them all in hand prior to commencing in Jan as we have a 4 day window.

all related components?

Welcome to the forum!
How many kilometers are on the odometer?
Do you plan to replace all of the camshaft timing related components because you only have four days to perform repairs? If not, you may find a surprise when you inspect the components.
Does your engine have a balance shaft?
Have the intake manifold gaskets ever been replaced? If not, I suggest replacement.
I recommend you use the OTC 6488 timing tool kit since it will save time and reduce the risk of timing the camshafts.
OEM Ford parts in Australia are expensive. You may want to consider an aftermarket parts kit.

Click on the link to "My Helpful Threads" in my signature for timing chain related threads.

Thanks Streetrod,
There are currently 156000 kms.
Wasn't planning on replacing all of the camshaft components, no, however that all depends on this surprise? I'm guessing its one of the nasty variety?
Yes it does have a balance shaft
The manifold gaskets havnt ever to my knowledge and I highly doubt it. I will be sure to add it to the order list.
Will be sure to get my hands on the OTC kit as well as the crankshaft holding tool to try make the job easier and smoother.
Have spoken to Ford about the parts, came in at over $1700 and they can't actually confirm its the upgraded slides ect. I then grabbed the part numbers off them for a number of parts and looked online and they did marry up with the explorer parts so an aftermarket kit will definitely be the way to go.
As I said im in the phase of trying to get everything i could possibly need to get for the job so that we can have a solid crack at finishing it off in the 4 days.
Greatly appreciate the help!

complete timing parts kit

There is a good possibility that your balance shaft chain tensioner, primary (crankshaft to jackshaft) chain tensioner have failed. Also, there is a lesser possibility that one or both cassette guides have failed but you won't know until you remove the valve covers and the timing cover. You probably should buy a complete parts kit to avoid delays when ordering "discovered" failed parts. You may be interested in reading SOHC V6 Timing Chain Parts Sources

Thanks, had a quick read through that and will endeavor to find a OEM complete parts kit. I imagine it will still be alot cheaper ordering from the US as Ford here didnt have any kit options for this engine. I do plan on keeping this car for some time so i'm willing to play a little more for the right parts. This engine was only in the country for 2 years in the Courier and Mazda Bravo before they changed model and cut the petrol option all together. This makes sourcing parts for this motor somewhat difficult.
Thanks again for the quick replies

Tasca parts

I purchase all of my new OEM parts from Tasca Parts. However, I'm afraid you'll be disappointed in the prices - especially after paying the import fee. Ford does not sell complete kits like the aftermarket sellers. I expect your cost for parts will exceed $2,000 US. You could potentially save a lot by only purchasing replacements for failed parts but then the vehicle will be down between identifying the parts and ordering/receiving replacements.

Thanks, i was expecting this job to be within that price range for parts. For all of the timing cassette parts Ford Australia quoted me over 1700 which was only scraping the surface of the parts im going to require for the job not to mention they couldnt tell me if the slides were the original or the reinforced.
Ill be sure to let you know how it all goes, thanks for the info!

I am in the middle of the reassembly stage. I removed both heads as one of the gaskets was blown. As a result, I removed both cams. The LH cam has the CPS stub that sticks up at TDC. The right hand one, however, has two flat spots, one on either side. I put a mark on one of the flat spots, and I am pretty sure it was at TDC when I did that, but I am not 100% positive. Is there a trick other than the flat spot method I have seen people mention to make sure it is in phase with the other cam? If I put the mark side up, the front lobes for #1 point up at about 45 degree angles, and there is tension on the exhaust valve for #3 . Is this correct? The other way there is no tension on any of the valves, which matches the other cam, so I am assuming that is wrong.

use the timing slots

When piston 1 is at TDC the timing slots for both camshafts should be below the axis of the camshaft and parallel to the head surface that mates with the valve cover.

That's the only accurate method.

Perfect! I never noticed the offset. Thanks much! :)


hey for those of you needing the tool kit for the 4.0 sohc timing chain go to specialty auto tool rentals there in Chicago they ups it to you, 5 day rental + ups less than $100 hope this helps

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