How to: SOHC V6 Timing Chain Parts Removal Procedure

[flwest05]

Loosen right camshaft sprocket bolt

Loosen (clockwise) right camshaft sprocket retaining bolt. A universal sprocket holder similar the one shown below may be used to prevent the sprocket from rotating.
View attachment 64396
If you have the OTC 6488 timing tool kit camshaft gear holding tool (6478) and camshaft gear holding tool adapter (6482) can be used to prevent the sprocket from rotating.

 

[rewind1]

I currently have my engine out and have already replaced my rear timing chain.
I am working on the front now and specifically the balance shaft chain but I have two problems...

1 - I cant seem to get the balance shaft chain sprocket off of the crank shaft, the keyway is lined up but it's not clearing it. Almost as if the key on the crank is raised.
2 - The keyway on the crank is straight up but the timing marks on the balance shaft sprocket are not lined up correctly.

 

[Tech By Trade]

Take the entire balancer off and spin it until it lines up and put it back on, the gear is not to be taken off.

 

[2000StreetRod]

The balance shaft timing will be correct unless the chain has been removed or broken and replaced. It may take as many as 7 rotations of the crankshaft before the timing marks on the balance shaft sprocket line up correctly. Do not loosen the balance shaft sprocket retaining bolt. There are no alignment marks on the balance shaft. See the following thread: http://www.explorerforum.com/forums...e-shaft-timing-procedure.400819/#post-3250999

 

[rewind1]

Thanks for the info on the alignment @Tech By Trade and @2000StreetRod.

Any thoughts on why I can't seem to get the sprocket off the crank? I'm contemplating not even changing the balance shaft chain now because it seems impossible without damaging the crank. I must be missing something simple.

 

[Tech By Trade]

Pull the balance shaft to get the chain off, then the crank sprocket should pull straight off.

 

[rewind1]

My bad, I didn't realize that the keyway pops out. Dad had to show me. At least I learned something new today.
Thanks for the replies and thanks for the wealth of information Dale!

 

[Drewmcg]

First, a thousand thanks to Dale (2000streetrod) for his many helpful guides on this engine!

I'm on my second engine pull/timing chain replacement on 3rd gen Explorers (June 2002 motors, both of 'em). One had a completely shattered right (rear) cassette at 176k miles (confirming Dale's view that even the re-designed cassettes fail); the other has no issues and still runs strong at 116k miles. But I'm changing the primary and two upper timing chain kits on this engine for longevity, while I have it out and on an engine stand. I know from replacing the rings and close examination of the cylinders on the higher-mileage engine that these cast iron German (?) blocks stand up to miles extremely well.

At post #15 of this (removal) thread, there is a potential landmine. In it, Dales suggests using both camshaft locking tools from the OTC 6488 kit to hold the right cam when loosing the right (reverse thread) camshaft sprocket nut. Do not do this--or if you do so, only use both with a breaker bar to break torque, then remove the sprocket locking tool (OTC 511546, aka # 6478, "Ford Camshaft Gear Holding Tool," with the circle/pins insert, # 511550, aka # 6482). Here's why:

The camshaft sprocket bolts on these engines have a very thick, heavy gauge washer. If you place the camshaft sprocket locking tool from OTC kit on the right (rear) sprocket, and then do what I did and buzz it out with an impact wrench, you risk fouling the last couple of threads of the threaded socket in the end of the right camshaft that holds the bolt! There is not enough depth for the bolt w/washer to fully extract with that tool in place, but this is not obvious to the mechanic. The thick washer binds on the tool but cannot slide over the treads of the bolt.

I believe this is precisely what happened to the poster in this thread: www.explorerforum.com/forums/index.php?threads/how-to-remove-install-camshaft-on-sohc-v6.316780/ . Swapping camshafts to solve the problem (if one is available) brings its own major problems and risks, as discussed in that thread.

The fix I am pursing is to order a left-hand thread M10 X 1.0 tap (plug taps are more common; tapered tap preferred); to clean up the thread; and reinstall with my new timing chain cassette.

Unfortunately, left hand thread taps are next to impossible to find. Regal Cutting Tools in Chicago has them, but would not sell direct to me. They would ship next day to a local Fastenall, but at a price I found unacceptable (nearly $100). So I'm waiting 2-3 weeks for a <$20 solution from China. Good thing I have lots of other projects to do on this vehicle in the mean time!

I doubt very much that the gear holding tool is needed to break tension on the rear jackshaft bolt in the first place, at least if you've got the camshaft locking tool on the front of engine on the passenger side and have not already loosened the cam bolt on that side. Just be sure that the two cutouts in the front end of the right camshaft fully engage the nubs on OTC 6480 before trying to turn the rear jackshaft bolt. Sames goes when you're removing the right camshaft bolt.

Use the same precautions when removing the left (front) cam sprocket bolt.

 

[Dbbooth]

Thanks so much for all the posts on this. I just finished my sons 97 Explorer using all the info I got here. We'll be cranking it up and testing tonight. Wish us luck and thanks again for all the help!

 

[hondaslave1342]

SOHC V6 assembly instructions

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

I sure would love a copy also..thanks a million

 

[2000StreetRod]

I sure would love a copy also..thanks a million

I'll need your email address.

 

[hondaslave1342]

mderanian@yahoo.com..thanks so much..i bought a 05 st and didnt have a clue about these timing chains..i changed several timing belts and i dread tackling this mess..my st has 210000 runs great but has the rattle at start up...im thinking about selling it but dont want to put someone through this..i dont feel right about it..so taking the engine out is recommended..thanks

 

[Dalin]

First, thanks for the very helpful explanations. I unfortunately removed the balance shaft sprocket bolt . What have I done?? In other words, how do I get back on track?

 

[2000StreetRod]

From what I've read the position of the balance shaft relative to the crankshaft is determined by the factory using balancing equipment. Even though you have loosened the balance shaft sprocket retaining bolt the back face of the sprocket may still be "stuck" to the balance shaft. If so, tighten the sprocket retaining bolt while keeping the sprocket from rotating and hope that the balance shaft does not rotate in the process. If the sprocket rear face has broken free from the balance shaft then you might remove the sprocket and look for discolorations that would help match the two faces. If that process fails then I don't have a resolution other than just tightening the sprocket retaining bolt and hope for the best. You probably won't detect additional vibrations unless you drive in all wheel drive low range with high engine speeds.

 

[Stic-o]

I have a question. I see there is talk about 4wd vs 2wd motors and having a extra sprocket on 4wd. What benifit does this have and is it required? Can a 2wd add the additional sprocket?

I have a 2000 sohc 2wd that does not have broken guides yet, but planning to replace as the motor will be swapped into a 4wd. Motor has about 105k on it Appreciate any advice or pointers.

 

[2000StreetRod]

The extra sprocket you're referring to drives the balance shaft.

The theory is that the balance shaft reduces harmonic engine vibrations that may occur when driving in 4WD low at high engine speeds. As I recall the block castings for the balance shaft engine differ from those for the engines without the balance shaft so it is not possible to add the balance shaft to a block. Even if it was possible, a balance machine would be needed to time the balance shaft to the rest of the rotating assembly. I suspect the factory had the option of using either engine on the production line. Some 2WD vehicles have a balance shaft engine. Possibly they were installed to keep the production line going when there were no non-balance shaft engines. My 2005 Mustang engine assembly instructions includes the balance shaft and there were no 4WD Mustangs in production. Since a balance shaft increases rotating mass it would slightly inhibit rapid engine acceleration. If you search the forum you will learn that there is an ongoing controversy regarding the need for the balance shaft. It's my opinion that if you don't frequently participate in off road hill climbs you don't need a balance shaft engine.

If you're going to replace the cassettes become thoroughly knowledgeable on the process before proceeding. Even some engine shops with personnel not familiar with the engine have misinterpreted the assembly instructions and destroyed the valves on engine start after rebuild. Some common errors besides incorrectly timing the camshafts 180 degrees off are breaking off the passenger side sprocket retaining bolt by turning it the wrong direction or over torqueing when using the special tool. Don't buy junk cassettes if you value your time and the valve train.

 

[CDW6212R]

I suggest avoiding the balance shaft if you don't need it. That tiny chain and its tensioner are super fragile. I somehow broke the tensioner during or after my service work(I discovered it after having the rest back together). That made me have to buy those parts, and in checking the timing of the balance shaft chain(to install, which is why I was leaving those untouched), it was way out of time. To re-time that required removing the balance shaft completely, and lining up the chain while reinstalling it. The upper oil pan has to come off to get to it also.

I'd do away with it this time if it was simple to do, but it's not.

 

[Drewmcg]

The extra sprocket you're referring to drives the balance shaft.
View attachment 153450

Don't buy junk cassettes if you value your time and the valve train.

Amen to this advice! Having done this job twice (different engines; both removed from truck), I'd hate to re-do. I used the Cloyes kit b/c I thought they were OEM at the time (plus they have a very good youtube video on how to install & time engine), but have since learned (here) that Motocraft is different. I'd shop around for cheapest Motorcraft cassettes guides and tensioners if doing again. I doubt very much that the chains, sprockets, and other hardware make much difference (if you even have to replace), since the tensioners/guides are the fail points here.

Whatever kit you buy, do go to dealer for those super-thin washers that fit under the large wrench/sockraet surface of the tensioners (buy an extra set just in case you have to re-install, e.g., to deal with an oil dribble, and you bend one, which is easy to do). You cannot find them easily aftermaket.

15k after installing new chains on the second engine and the thing runs like a dream. Just finished a 3k+ mile trip to Texas and back. Thanks, again, to 2000StreetRod, et al., for the wonderful tips. You guys are awesome! Happy New Year! Drew.

 

[Stic-o]

So just to recap...

• do research and then more research
• understand the procedure fully before starting
• get a high quality kit.
• extra sprocket is not needed.....although this will be used in a 4wd truck that will be used for 4wd.....and I don't mean just dirt roads.

 

[2000StreetRod]

If you send me your email address in a conversation I'll send you a copy of the engine assembly instructions. Do you have the OTC 6488 timing tool kit?

It is not essential but makes the camshaft timing easier and more precise.