SOHC V6 Timing Chain Saga

[2000StreetRod]

cam & sprocket

The hub on the camshaft fits into a recess on the rear of the sprocket as identified below. This keeps the sprocket centered on the camshaft.

The sprocket retaining bolt attaches the sprocket to the camshaft and keeps them from rotating relative to each other.

There is nothing on the hub that restricts the rotational mounting position of the sprocket. The timing slots are located on the camshaft end opposite of where the sprocket mounts.

 

[twford]

Thanks for the reply just trying to understand the timing a little more so the way i see it as long as you get perfect TDC and lock both cams from moving and lock the crank from moving from TDC you can remove everything and reinstall everything whith no change in the degree of timing.So iam having trouble trying to explain my second question but where is the play so to speak to get the timing to be off alittle.If you pull TDC and lock cams in place ,slide the gear off whith the chain on it and you turned the crank alittle the gear could still go on only one way so the gear would only go back on when crank was turned back to TDC where the cams were locked in the begining it seems you couldnt get it wrong? correct me if im wrong im just trying to understand It just seems like a traditional engine once you have your TDC dont let anything move basicly?

Edit-------
Just read trough your last post agin and seen that there is no slot for the gear on the cam so it can be installed in different rotational degres thats where the "play" is so to speak.Sorry i didnt read troughly before i commented.But still the same concept as long as crank or cams dont move you would be fine.So just the torqe of the cam bolts keep the cam gears from spinning on the cam shaft?

 

[Vargas]

just the torqe of the cam bolts keep the cam gears from spinning on the cam shaft

Exactly!

 

[twford]

Exactly!

Thats just stupid on fords part that could have made this process alot easier but cant change that now.

 

[CDW6212R]

Yes, the connection between the cams and the gears is completely friction, the force of the bolt holding the gear to the cam. It's the same for both ends of the jackshaft.

So don't remove anything unless the whole set of parts are all at TDC. You can't move the crank separately from either cam, the valves might hit pistons.

The tools only hold one cam at a time, thus you set the timing of each cam separately.

The play in timing I've mentioned possible, it's in the TDC tool. You can attach the TDC tool to the balancer at different depths of the balancer teeth. That affects where the side of the tool rests on the block or cover, which means a different TDC. The same was true of my block and timing cover, each provided a different timing, a different TDC. Everything to time the SOHC revolves around locating TDC of the balancer. If the tool can provide differing TDC results each time you put it on, that's not good.

The ideal way to time the engine, like any engine, is to locate the actual absolute TDC with a piston stop, and mark the balancer literally. If you take that one step to find the real TDC, not the calibration or machined accuracy of some various tool, then you will know it's right. Mark the balancer one time by finding the rear TDC. Then you can use the balancer mark to time the engine without that odd TDC tool. The whole point is to place the crank at TDC, and you have to do that several times during the process. Regards,

 

[twford]

Well i dont have the funds for fords tools but i do have fab skills so my plan is to just fine absulute TDC and fab a 1/8in. plate that will bolt to the rear of the crank and along the bottom of the oil pan to keep the crank from moving completly.Then ill fab something from steel to lock in the cam slots and bolt to the top of the head that way nothing moves.Thanks for the tech. info guys glad i found this fourm.

 

[2000StreetRod]

Adjustable cam timing

Thats just stupid on fords part that could have made this process alot easier but cant change that now.

One good thing about the SOHC V6 design is that it allows adjustment of the camshaft relative to the crankshaft. The characteristics of the engine performance can be altered by changing the camshaft timing. Unfortunately, it is not possible to change the timing of the intake valves relative to the exhaust valves unlike with a DOHC design.

 

[twford]

The tools only hold one cam at a time, thus you set the timing of each cam separately.

Just curious why you couldnt lock both cams in place at once, you shouldnt have to rotate the assembly to remove gears and chains, correct?

 

[CDW6212R]

There is only one tool made to hold one cam in the tool set. The same for the tool which locates the cam at TDC, there's only one. So those two tools will locate one cam at a time, while you set the crank to TDC.

You use the tools to set one cam at a time. The crank is attached to the jackshaft fully/permanently before you start on the cams. So each cam is done separately, in either order you like.

 

[Vargas]

Just curious why you couldnt lock both cams in place at once, you shouldnt have to rotate the assembly to remove gears and chains, correct?

As Don said, the official tool set only includes enough tools to hold them one at a time. When you delve into making your own tools for the job, be aware that you need to have a tool to hold the chain as well. Part on the timing procedure is to remove the hydraulic tensioners and replace with a tooled pin to simulate the chain position as it would be if the engine were running.

 

[tomj1102]

Hi can anyone tell me in which year did ford improve the tensioners and which models have the least problems.
Thanks

 

[2000StreetRod]

2002 camshaft timing improvements

I believe that all of the Ford SOHC V6 camshaft timing related improvements were incorporated in the 2002 model year. Unfortunately, Ford never reinforced the traction side of the rear guide assembly with metal.

 

[chrisjl]

Dale,
Do you happen to know the Felpro rear main seal part# that you used?

 

[2000StreetRod]

Rear Main seal

Dale,
Do you happen to know the Felpro rear main seal part# that you used?

I purchased the Fel-Pro rear main seal set BS 40619 from Rock Auto. I didn't use the sleave since the crankshaft was not worn.

 

[AussieExplorer1]

Thank you everyone for posting your opinions and answering my PMs regarding the orientation of the new style jackshaft rear plug. I searched the internet, reviewed the Ford assembly instructions and deliberated considerably before deciding how to install it. The photo below of the opening illustrates what finally swayed my decision.
View attachment 59040
The top of the jackshaft rear sprocket bolt is slightly lower than the bottom of the plug opening. The new plug has a cup that is slightly larger in diameter than the head of the bolt. When the plug is installed with the bare metal side out there is more clearance between the rotating bolt head and the plug. Another factor is I didn't like the idea of hitting the rubber covered side with something to drive it in. Also, I decided to paint the block Ford blue and the paint will adhere to the metal side much better than the rubberized side. I used my trusty 36mm socket to drive it in. It was necessary to relocate one of the engine stand support arms in order to drive it squarely. The completed installation is shown in the photo below.
View attachment 59041
Right or wrong, this is how it will be at least until my future engine rebuild.

Hi Guys , just a quick question , I have nearly totally dismantled my engine and one item is holding me back. The jackshaft rear sprocket that couples up the left hand side camshaft rear timing chain/sprocket.

What is the procedure in removing/undoing/losing the nut to enable me to remove the sprocket and chain from the jackshaft?

Any help would be appreciated.

Cheers

 

[2000StreetRod]

removing jackshaft rear sprocket retaining bolt

In order to loosen the jackshaft rear sprocket retaining bolt the jackshaft must be prevented from rotating. If the jackshaft front sprocket is still attached you can hold its retaining bolt while loosening (counterclockwise) the rear retaining bolt. The front bolt is torqued to a higher number than the rear bolt. If the primary (crankshaft to jackshaft) chain is still in place you can hold the crankshaft. If you have the OTC 6488 timing tool kit you can install the camshaft sprocket holding tool on the right sprocket to prevent the jackshaft from rotating via the timing chain. Otherwise, you'll have to come up with some type of sprocket holder to loosen the jackshaft sprocket and camshaft sprocket retaining bolts.

This link shows one method: Jackshaft rear sprocket loosener

Here's a universal tool for holding sprockets.

 

[AussieExplorer1]

Parts List ???

2000StreetRod;2721517In order to loosen the jackshaft rear sprocket retaining bolt the jackshaft must be prevented from rotating. If the jackshaft front sprocket is still attached you can hold its retaining bolt while loosening (counterclockwise) the rear retaining bolt. The front bolt is torqued to a higher number than the rear bolt. If the primary (crankshaft to jackshaft) chain is still in place you can hold the crankshaft. If you have the OTC 6488 timing tool kit you can install the camshaft sprocket holding tool on the right sprocket to prevent the jackshaft from rotating via the timing chain. Otherwise, you'll have to come up with some type of sprocket holder to loosen the jackshaft sprocket and camshaft sprocket retaining bolts......

Hi 2000StreetRod, Thank you for the reply , I made a sprocket lever holder , which i attached it to the front jackshaft sprocket and used a correct torque screw wrench size to loosen the rear retaining bolt head to remove the rear jackshaft sprocket.

I tried clockwise and anticlockwise seems I need to have a bigger breakfast and put some muscle into it.

In my case seems the rear retaining screw is tighter than the front.


I'm looking at purchasing a " 1997-2005 Ford Explorer 4.0 SOHC , Ford Explorer Cam Tool Kit 4.0L V6 - No. OTC-6488 Sale Price: $200.45 , from http://www.spx.usatoolwarehouse.com/spx-store/OTC-6488.html . Here in AUstralian the parts are poisson to buy one has to sell a arm and a leg and have no idea why so expensive as compared what one can purchase in the USA.

I need a full timing chain/sprocket/slider kit for my vehicle and also rings , main and big end bearings. On my vehicle the engine failed due to the main chaining driving of the lower crankshaft gear to the jackshaft gear just popped off the top jackshaft sprocket, hence no rotation of the camshafts. Further more the valves did touch all the pistons and will overhaul the heads.

Just admiring the head design as far as flow characteristics would go, haven't flow tested these heads but now there off i will, all in all the heads would make beautiful platform for developing more horsepower. Further more when I removed the pistons out of each holes. The rings on several pistons are seized in there ring lands some top compression rings and on others oil control rings are seized . This is the perfect opportunity to freshener up the engine.

In the bottom of the sump I found large amounts of fragments of plastic and something resembling very thin metal bearing shells. Definitely not the mains/big end bearings as they are like new except for one which has copper showing and some scuff marks. Anyone have any idea what the thin metal curved strips are ????

I will be purchasing all the components from the USA and fleabay. If anyone cares to share who has quality parts and good price just drop me a PM on the shops details.

So I'm in need of the following parts , fully timing chain/sprocket/slider/tensioner kit , rings , main bearing and big end bearing kit , plus a full engine gasket and seal kit and Explorer Cam Tool Kit 4.0L V6 - No. OTC-6488.

Also chasing a workshop manual as we can not purchase one from Ford Australia. Not available for public consumption. Need a manual for all the vital specs and for further maintenance of my recently acquired Ford Explorer to do some off-road 4WDing

Just curious what after market parts brand names are available for the Ford Explorer 4.0L SOHC V6 engine ( Cloyes , felpro ?????? or genuine Ford ??? ).

Cheers

 

[CDW6212R]

Try to buy OEM Ford parts for the SOHC valvetrain parts, anything else is suspect.

For price comparisons, try to check with Tasca Ford online, they are likely the largest Ford parts source there is. Try to use part number, their description catalog etc, is good, but it doesn't give you any part numbers to verify IIRC.

Tasca Ford parts - Home page

FYI, those odd parts in the pan, those are pieces of the front tensioners. When you see the new parts you will understand how they are made. Regards,

 

[AussieExplorer1]

HUGE bowl of kellogg corn flakes and milk for breakfast Popeye the sailor man

Try to buy OEM Ford parts for the SOHC valvetrain parts, anything else is suspect.

For price comparisons, try to check with Tasca Ford online, they are likely the largest Ford parts source there is. Try to use part number, their description catalog etc, is good, but it doesn't give you any part numbers to verify IIRC.

Tasca Ford parts - Home page

FYI, those odd parts in the pan, those are pieces of the front tensioners. When you see the new parts you will understand how they are made. Regards,

Hi CDW6212R , thank you for you information and reply to my questions. Had my suspicions that the thin metallic curved strips are part of the tensioner/guides construction but wasn't 100% sure.

Ok just had my HUGE bowl of kellogg corn flakes and milk for breakfast, feel like Popeye the sailor man with the aid of a friend just undid my rear jackshaft gear retaining screw which on my engine is a RHS thread.

Q1. Apart from the month/year manufacture date of the vehicle I own , how hoes one identify the engine block details? " 1997 Explorer 4.0L SOHC V6 Auto Trans"

Q2. What markings do I refer to on the engine block seems there are a few different types of variation of this blocks version?

Q3. How does one post pictures directly to this thread on this forum ?

When I go to the control panel in the reply section the " insert image " feature is requesting a " please enter a URL of your image " http:// ??? I'm assuming I must use a web picture storage website ??? Yes or No ? or can one attach pictures directly in the forum?

cheers

 

[2000StreetRod]

clockwise vs counterclockwise

I believe the only timing chain related counterclockwise tightening bolt is the rear camshaft sprocket retaining bolt. All other bolts tighten clockwise. If you had read the thread linked in my last post I pointed out that it took 70 ft-lbs to loosen the jackshaft rear sprocket retaining bolt. I have used a chain attached between the jackshaft front sprocket and the head to keep the jackshaft from rotating.
Left guide replacement - no OTC-6488 use

I agree with CDW6212R that purchasing Ford OEM timing chain components will achieve the best quality parts. The only other manufacturer I would consider is Cloyes since one of their engineers assured me that their guide assemblies were obtained from the same manufacturer that supplies Ford. Timing chain related part numbers that I try to keep current are here: Requirements for accurate timing

If you PM me your e-mail address I'll send you a copy of the 2005 Mustang SOHC V6 assembly instructions.