SOHC V6 Timing Chain Saga

[2000StreetRod]

About the same

Also, did you find the new tensioner much stronger than the old one, or were they similar?

About the only difference between the new and old tensioners was there is a worn area on the old one at it's normal position. It can be felt and heard as the plunger is compressed.

 

[2000StreetRod]

Another guide piece

I suspected there were two more signficant sized pieces of the guide assembly still somewhere in the block so I looked for them. I found one lodged between the jackshaft and the housing as identified by the arrow in the photo below.

I tried unsuccessfully to extract the piece using a long thin screw driver and then using a wire with a short hook on the end. There was just not enough clearance to get it out so I removed the jackshaft. The arrow in the photo below identifies the piece.

It was easily removed with long nose pliers without the presence of the jackshaft. I examined the jackshaft galley area with a light and could not see any more pieces there. Frankly, I don't see how any could get there since there is no opening except for the jackshaft bearing that is normally filled with the jackshaft journal.
The photo below is thru the front jackshaft opening. The galley obviously has a significant buildup of sludge.

The item sticking up at the other end is the small spiral gear that is driven by the jackshaft gear and it turns the oil pump intermediate shaft. I rotated the gear several times looking for guide particles but found none.

 

[CDW6212R]

I know you will clean inside the engine some. Please don't try to get everything, avoid harsh cleaning chemicals that may end up in crevices or oil galleries. Use any cleaner as long as you keep it isolated to the place where you spray it or wipe it on.

You don't need to remove all of the "sludge," just try to wipe away the soft or loose stuff without dislodging stuff that then ends up circulating. I think you are doing great, keep at it carefully.

 

[shelbygt]

I have finally started the reassembly, but the Ford tool needs the timing chain cover and balancer installed in order to hold everything to tighten the jackshaft and rear sprocket bolts. Should I use the chain method, or is there another trick to set the torque plus the 90 degrees on the jackshaft?

 

[2000StreetRod]

Another Ford special tool

I have finally started the reassembly, but the Ford tool needs the timing chain cover and balancer installed in order to hold everything to tighten the jackshaft and rear sprocket bolts. Should I use the chain method, or is there another trick to set the torque plus the 90 degrees on the jackshaft?

Ford has another special tool (303-674) that is not included in the OTC-6488 timing kit. I think it is a special socket that fits over the crankshaft end and uses the key to prevent the crank from turning while the jackshaft sprocket is torqued. Some members have used the jackshaft rear bolt to keep the jackshaft from rotating while tightening the front bolt. I advise against that for two reasons. The first is that not everyone is also replacing the rear chain. The second, which is more important, is that using that method will overtorque the jackshaft rear sprocket bolt and might shear it off. I intend to use my chain method with one end bolted to the head and the other end bolted to a hole at the bottom of the jackshaft front sprocket.

One important point that I intend to mention in another thread I've started about timing the camshafts: even with the timing tool set the timing will not be accurate unless the chain is kept taught on the traction side when the camshaft sprocket is tightened. The special "calibrated" tensioner included in the kit is what tensions the traction side of the chain. The spring pressure of the normal tensioner is insufficient to achieve the required tension for accurate timing. This is something that has been overlooked by those who time their camshafts without the timing kit.

Good luck on your assembly and timing!

 

[2000StreetRod]

Cleaning process

I know you will clean inside the engine some. Please don't try to get everything, avoid harsh cleaning chemicals that may end up in crevices or oil galleries. Use any cleaner as long as you keep it isolated to the place where you spray it or wipe it on.

You don't need to remove all of the "sludge," just try to wipe away the soft or loose stuff without dislodging stuff that then ends up circulating. I think you are doing great, keep at it carefully.

At this point I only plan to use engine flush as a cleaner. My next step is to rotate the engine to an upright position on the stand and spray engine flush into the area normally occupied by the rear cassette. I'll watch carefully to see where the flush drains out. Then I'll invert the engine and spray flush into the drains. My suspicion is that there is still one large piece of guide trapped in a narrowing oil return passage. Hopefully the combination of gravity and engine flush will free the piece and it will drop out. If that doesn't produce a piece I'll blow air into the inverted drains.

I am really serious about preventing a future recurrence of what happened. I was very lucky not to have a chain break at almost 6,000 rpm with all the large pieces of plastic bouncing around. I don't want to risk damage to a pair of Supersix Motorsports stage 2 heads because of rear timing chain guide fatigue which will not be prevented with a pre-oiler. If I can find a way to adequately tension the chain without the traction side of the guide assembly I'll do it.

 

[shelbygt]

Thanks Dale, I am going to use your chain method, as it worked great to remove them!

One more thing that just came up is ...the rear cassette kit from Ford did not come with a new jack shaft bolt (old one is in photo below) Since this requires a torque plus additional degrees, I would think it must be replaced since the old one was stretched?

Yeah the OTC kit has that "special" tensioner and it is tighter than the actual one that goes in the motor. What will you use on yours to keep it tight?

rear jack shaft bolt

Going back together....

 

[2000StreetRod]

special tensioner

. . . One more thing that just came up is ...the rear cassette kit from Ford did not come with a new jack shaft bolt (old one is in photo below) Since this requires a torque plus additional degrees, I would think it must be replaced since the old one was stretched?

I agree. That's one I don't have a part number for yet.

Yeah the OTC kit has that "special" tensioner and it is tighter than the actual one that goes in the motor. What will you use on yours to keep it tight? . . .

I'll be using a long threaded bolt, a washer, a nut and a piece of hose to protect the threads on the tensioner opening. I'll place the hose on the bolt near the head, pass the threaded bolt shaft thru the opening, install a washer and nut, and then tighten the bolt until the desired tension is applied to the guide.

 

[Glen4X4]

Not trying to high jack your thread here but this is what my motor replacement looks like at 140k I bought off forum member Spas she used nothing but Mobil1 Full synthetic in it, I decided to replace the guides and tensioners before it goes into the truck and this is what I found no sludge! I was honestly surprised after seeing your engine and seeing other posts of reported sludge found when doing the guides.

 

[shelbygt]

I am convinced the "sludged" motors are a result of a faulty or missing thermostats. I have torn dozens of V-8s apart with this very problem.

 

[shelbygt]

Anyone replacing the rear cassette, you will need to order the bolt separately as it is not included in the kit. I will post the part number one I get the bolt.

Yet another day or so waiting for a 10.00 bolt ...that must be replaced to change the rear chain or cassette, yet Ford doesn't believe it should be included in the kit?

 

[blueka]

subscribing cos I'm gonna need this in a few weeks I think...


Si

 

[2000StreetRod]

Good comment!

I am convinced the "sludged" motors are a result of a faulty or missing thermostats. I have torn dozens of V-8s apart with this very problem.

I was thinking the same thing. This orginally was a Texas vehicle with a single row radiator. I'll bet it had overheating problems in the summer and the owner removed the thermostat in an ignorant attemt to alleviate the problem.

 

[2000StreetRod]

Helpful thread with part numbers

Anyone replacing the rear cassette, you will need to order the bolt separately as it is not included in the kit. I will post the part number one I get the bolt. . .

I started another thread linked with My Helpful Threads about timing the camshafts that includes current part numbers as I determine them. I'm concerned that some Ford dealers have started supplying the left (front) tensioner as a replacement for the right (rear) tensioner. I'll be looking for the jackshaft rear sprocket bolt PN.

 

[2000StreetRod]

Very nice!

Not trying to high jack your thread here but this is what my motor replacement looks like at 140k I bought off forum member Spas she used nothing but Mobil1 Full synthetic in it, I decided to replace the guides and tensioners before it goes into the truck and this is what I found no sludge! I was honestly surprised after seeing your engine and seeing other posts of reported sludge found when doing the guides.

It will take me several days before my engine starts to look as good as yours!

 

[CDW6212R]

I started another thread linked with My Helpful Threads about timing the camshafts that includes current part numbers as I determine them. I'm concerned that some Ford dealers have started supplying the left (front) tensioner as a replacement for the right (rear) tensioner. I'll be looking for the jackshaft rear sprocket bolt PN.

That's a great idea to collect and index the parts list.

Which bolt in back is it that needs to be in the kit? Is it the top one or the one below the head? I remember the rear one having nothing but the cassette before I took it back. Does this in mine look like the old version? I didn't know that there were more than one revision?

 

[2000StreetRod]

a little confusion

. . .
Which bolt in back is it that needs to be in the kit? Is it the top one or the one below the head? I remember the rear one having nothing but the cassette before I took it back. Does this in mine look like the old version? I didn't know that there were more than one revision?

The bolt that should be included in the cassette is the one that screws into the rear of the jackshaft behind the plug. The cassette includes the chain, jackshaft rear sprocket, camshaft sprocket, guide assembly and guide assembly pivot bolt. The chain and jackshaft rear sprocket cannot be changed without removing the torque to yield jackshaft bolt. That's why it should be included as part of the cassette.

Your hydraulic tensioner is the old style that is several inches shorter on the outside than the front hydraulic tensioner. At least one Ford dealer is shipping the front hydraulic tensioner for an ordered rear hydraulic tensioner.

There are two versions of the rear guide assembly. The old style is all plastic on the slack side where the tensioner contacts it. The new style is metal backed on the slack side. Yours appears to be the old style but I can't see enough of it to be sure.

My guide assembly failed structurally on the traction side which is all plastic on both the old and new style.

 

[CDW6212R]

Ah, the actual rear jackshaft bolt. When I did the front I wanted to replace it all, but some of the prices were fairly high, and my guy then was not doing right by me for pricing. Now we have tons of online sites to compete with the local dealers. If people can wait on ordered parts, they can save a good chunk of money.

 

[Jakee]

Very good job so far.

So, when will the forged rods and pistons go in?

 

[2000StreetRod]

Jackshaft sprocket bolt PN

Anyone replacing the rear cassette, you will need to order the bolt separately as it is not included in the kit. I will post the part number one I get the bolt.

Yet another day or so waiting for a 10.00 bolt ...that must be replaced to change the rear chain or cassette, yet Ford doesn't believe it should be included in the kit?

The part number for the jackshaft rear sprocket retaining bolt is W703167S430. For a rapidly growing list of timing chain related Ford part numbers go to: SOHC V6 Camshaft Timing