How to: SOHC V6 Rear Cassette Replacement

[03lances]

Thanks guys. I remember seeing that trick with the chain bolted to the flexplate. Makes me nervous with torquing on it while dangling from an engine hoist lol. Then again I think ill reattach the mounting bolt plates and then set the engine on jackstands with the hoist still attached to help stabilize while I today that puppy on. Why can't they be like all the imports I work on where I can just slap my impact on the pulley bolt and blast away lol.

That makes sense about the cams timing to the jackshaft. I assumed it wouldn't matter which head I timing first but we all know where assuming can get us Haha. The kit has the chain tensioner tool in it do I should be able to just screw that in then lock the gear and the shaft with the other tools and timing should be right on according to your guide correct?

Thanks again for the assist.

 

[03lances]

Stupid phone autocorrect. Torque not today lol.

 

[03lances]

So I just thought of something I booboo'ed. I have already installed the front timing cover and I still havent got the rear jackshaft bolt so I cant use the chain trick to torque that rear jackshaft sprocket. Realllllly dont want to remove that front cover again either since I was nervous about leaks so I used rtv along with the gasket. as I Here is my plan though. Using the method you wrote out with locking the right (rear) camshaft to tighten the front jackshaft bolt I am going to use that for the rear. This does however mean that I have to time the left cam before I can tighten the rear jackshaft. Then I can just time the right cam.

 

[2000StreetRod]

tightens clockwise

Both the rear jackshaft sprocket and harmonic balancer retaining bolts tighten clockwise. I tightened the rear jackshaft sprocket retaining bolt while holding the harmonic balancer retaining bolt. The primary chain keeps the jackshaft from rotating when holding the harmonic balancer retaining bolt. The specified torque for the rear jackshaft sprocket retaining bolt is significantly less than for the front jackshaft sprocket retaining bolt.

 

[03lances]

Both the rear jackshaft sprocket and harmonic balancer retaining bolts tighten clockwise. I tightened the rear jackshaft sprocket retaining bolt while holding the harmonic balancer retaining bolt. The primary chain keeps the jackshaft from rotating when holding the harmonic balancer retaining bolt. The specified torque for the rear jackshaft sprocket retaining bolt is significantly less than for the front jackshaft sprocket retaining bolt.

This is true about the torque spec on the front rear sprockets. However my harmonic balancer bolt is also not tight yet lol. Also lower oil pan bolts torque 6-8 ft ibs?

 

[CDW6212R]

Just stick the crank bolt in the crank to hold the crank, that will do fine.

 

[mboyer2]

Sorry to bump an old topic but I am thinking about tackling this adventure on my parents 2003 Explorer 4.0L SOHC Flex Fuel and the tool kit OTC 6488 says that it is good for SOHC engines from 1997-2002, will it work on a 2003? Thanks for any help.

 

[2000StreetRod]

OTC 6488 applications

It's interesting that some vendors only show it being applicable thru 2002. Some show it for thru 2004. Summit Racing shows it thru 2011 for the Ranger. I could not find any that show it for the Mustangs although my 2005 Mustang SOHC V6 assembly instructions show using it. I know there was a change in the harmonic balancer design in the 3rd generation Explorers. Maybe the tool for holding the crankshaft won't fit for the later balancer. Anyway, you should not have any problems using the tool set on your 2003.

 

[SoFlaLivin]

I didn't use the tool kit , even with the tool it can still move . I made marks with an ice pick on both cams and timing marks , remember as soon as you loosen up the front jack shaft bolt the left cam will move but if you have it marked your ok . Buy the parts from Ford don't waste your time with others.

 

[wangbungal]

I am planning to change both head gaskets of my 2003 ford explorer sohc flex 6.0, I am not planning to pull the engine, would the steps be similar? I already got most out, rockers,lash adjusters and intake manifold, I just need help, whats next to be done, I got the otc 6488, my question is do I really have to unbolt the rear jackshaft bolt? or i could get away by just unbolting the sprocket bolt and cassette holding bolt? and not much room back there, any help would be appreciated!

 

[2000StreetRod]

head removal

I'll have to check my shop manual but as I recall it is possible to remove the right head without removing the jackshaft rear sprocket. I also doubt it is necessary to remove the cam followers. The cassette upper positioning bolt must be removed because it attaches to the head. The cassette lower positioning bold is in the block and not accessible without separating the engine from the transmission. Therefore, the cassette must be left in place. The right camshaft sprocket retaining bolt is loosened (loosens clockwise/left hand threads) with the OTC 6488 special tool. The head bolts are loosened/removed (don't forget the smaller ones). Then two people are required. One to remove the camshaft sprocket and keep the chain held upward with a wire or strong cord to keep it from dropping as the other person lifts the head off the block. The first person will also have to keep the cassette from interfering with the head as it is raised. The first person grasps the chain from below the head when the head is raised enough and releases the wire/cord so the second person can take the head away from the engine compartment. Tie the chain with the wire/cord so it does not fall into the block. The process is followed in reverse order when installing the head. Remember that the camshaft sprocket adapter provides additional leverage which is why the torque specification for the right head differs from the left which does not use the adapter. Also be advised that many "click type" torque wrenches do not work when tightening counter-clockwise. You may have to use a deflection gauge (the old style) torque wrench. When working with the heads be very careful of the cam oiler tubes. They are easily bent and broken.

 

[wangbungal]

I'll have to check my shop manual but as I recall it is possible to remove the right head without removing the jackshaft rear sprocket. I also doubt it is necessary to remove the cam followers. The cassette upper positioning bolt must be removed because it attaches to the head. The cassette lower positioning bold is in the block and not accessible without separating the engine from the transmission. Therefore, the cassette must be left in place. The right camshaft sprocket retaining bolt is loosened (loosens clockwise/left hand threads) with the OTC 6488 special tool. The head bolts are loosened/removed (don't forget the smaller ones). Then two people are required. One to remove the camshaft sprocket and keep the chain held upward with a wire or strong cord to keep it from dropping as the other person lifts the head off the block. The first person will also have to keep the cassette from interfering with the head as it is raised. The first person grasps the chain from below the head when the head is raised enough and releases the wire/cord so the second person can take the head away from the engine compartment. Tie the chain with the wire/cord so it does not fall into the block. The process is followed in reverse order when installing the head. Remember that the camshaft sprocket adapter provides additional leverage which is why the torque specification for the right head differs from the left which does not use the adapter. Also be advised that many "click type" torque wrenches do not work when tightening counter-clockwise. You may have to use a deflection gauge (the old style) torque wrench. When working with the heads be very careful of the cam oiler tubes. They are easily bent and broken.

haynes manual is confusing, as I have no means of removing that plug and bolt and a reason to do it, but they put it in the steps, so i have to remove the Rear cassete bolt and the sprocket bolt thats it right? the cam followers you mentioned is the rocker arms and lash adjusters right? I dont see a reason for doing that as well but is listed as one of the steps,


I installed back the rocker arms and the lash adjusters,I just want to know if you could verify the steps in doing the cylinder heads,


RIGHT SIDE,

Rotate engine to TDC, install OTC Holding tool to keep it on TDC,
install CAM holding tool and cam holding tool with pins OTC 6488
loosen CAM sprocket bolt RIGHTY LOOSEY
loosen CASSETE BOLT LEFTY LOOSEY
remove the holding tool
install a rubber band in the bottom and hook up a wire upward to keep the chain from dropping
unbolt head bolts using a PATTERN (dont forget the small ones)
lift the cylinder head up while keeping the wire or string on the sprocket
release the string or wire and catch the sprocket at the bottom of the cylinder head

LEFT CYLINDER HEAD (if you are seated at the driver side)

Do I install the cam holding tools for this as well?
I am thinking of doing this side first as it appears easy
unbolt cam sprocket bolt LEFTY LOOSEY
Unbolt cassete bolt LEFTY LOOSEY
UNBOLT the cylinder heads
lift the head

installation is reverse does it sound right to you OP?

 

[2000StreetRod]

hydraulic tensioner

The hydraulic/spring tensioner should be removed before loosening the camshaft sprocket retaining bolt.

My Haynes Manual for models thru 2001 states that the heads can be removed with the camshafts, rocker arms and lash adjusters in place. Bolts should be loosened 1/4 turn at a time. There are two 8 mm external Torx bolts and eight 12 mm internal Torx bolts. The 12 mm head bolts are torque-to-yield and technically should not be reused. However, they are expensive and I think many members do not buy new ones for non-performance engines.

Remember that counter-clockwise is based on being in a position where you are facing the head of the bolt. However, you might be in the front of the engine compartment facing the end of the threaded portion of the camshaft sprocket retaining bolt. So turn in the appropriate direction with the offset tool installed.

According to Haynes: "Do not pry the head from the block in the gasket sealing area. Use a pry bar at the corners of the head-to-block mating surface to break the gasket seal."

The camshaft holding tools should be installed on the camshaft prior to loosening the camshaft sprocket retaining bolt. Start with the left camshaft/head and then move the tools to the right camshaft.

 

[wangbungal]

The hydraulic/spring tensioner should be removed before loosening the camshaft sprocket retaining bolt.

My Haynes Manual for models thru 2001 states that the heads can be removed with the camshafts, rocker arms and lash adjusters in place. Bolts should be loosened 1/4 turn at a time. There are two 8 mm external Torx bolts and eight 12 mm internal Torx bolts. The 12 mm head bolts are torque-to-yield and technically should not be reused. However, they are expensive and I think many members do not buy new ones for non-performance engines.

Remember that counter-clockwise is based on being in a position where you are facing the head of the bolt. However, you might be in the front of the engine compartment facing the end of the threaded portion of the camshaft sprocket retaining bolt. So turn in the appropriate direction with the offset tool installed.

According to Haynes: "Do not pry the head from the block in the gasket sealing area. Use a pry bar at the corners of the head-to-block mating surface to break the gasket seal."

The camshaft holding tools should be installed on the camshaft prior to loosening the camshaft sprocket retaining bolt. Start with the left camshaft/head and then move the tools to the right camshaft.

UPDATED:

RIGHT SIDE,

Rotate engine to TDC, install OTC Holding tool to keep it on TDC,
install CAM holding tool and cam holding tool with pins OTC 6488
Remove Hydraulic Tensioner,( it is located at the rear of the cylinder head)
loosen CAM sprocket bolt RIGHTY LOOSEY (Facing the bolt head of course)
loosen CASSETE BOLT LEFTY LOOSEY
remove the holding tool ( Move it to the Left cylinder head cam and loosen the cam sprocket bolt)
install a rubber band in the bottom and hook up a wire upward to keep the chain from dropping
unbolt head bolts using a PATTERN (dont forget the small ones)
lift the cylinder head up while keeping the wire or string on the sprocket
release the string or wire and catch the sprocket at the bottom of the cylinder head

LEFT CYLINDER HEAD (if you are seated at the driver side)

Do I install the cam holding tools for this as well?
I am thinking of doing this side first as it appears easy
Install the holding tool
remove the hydraulic tensioner located in the front
unbolt cam sprocket bolt LEFTY LOOSEY
Unbolt cassete bolt LEFTY LOOSEY
UNBOLT the cylinder heads (again with the pattern)
lift the head

THANK YOU!

 

[2000StreetRod]

edited slightly

RIGHT SIDE,

Remove Hydraulic Tensioner,( it is located at the rear of the cylinder head)Rotate engine to TDC, install OTC Holding tool to keep it on TDC,
Install CAM holding tool and cam holding tool with pins OTC 6488
Loosen CAM sprocket bolt RIGHTY LOOSEY (Facing the bolt head of course)
Remove CASSETE BOLT LEFTY LOOSEY
remove the holding tool ( Move it to the Left cylinder head cam and loosen the cam sprocket bolt)
Remove cam sprocket bolt and then sprocket from chain
Install a rubber band in the bottom and hook up a wire to the chain upward to keep it from dropping
Unbolt head bolts using a PATTERN (dont forget the small ones)
Lift the cylinder head up while keeping the wire or string on the chain
Grasp the chain below the head and release the wire
Tie the wire to something to keep the chain raised

LEFT CYLINDER HEAD (if you are seated at the driver side)

Remove the hydraulic tensioner located in the front
Unbolt cam sprocket bolt LEFTY LOOSEY
Unbolt cassete bolt LEFTY LOOSEY
Remove cam sprocket bolt and then sprocket from chain
Install a rubber band in the bottom and hook up a wire to the chain upward to keep it from dropping
Unbolt head bolts using a PATTERN (dont forget the small ones)
Lift the cylinder head up while keeping the wire or string on the chain
Grasp the chain below the head and release the wire
Tie the wire to something to keep the chain raised

 

[wangbungal]

would it still be ok if i put it on tdc first then remove the hydraulic tensioner? would you mine telling me what the hydraulic tensioner, it would really help me understanding it more

 

[2000StreetRod]

Rear Timing Chain Tensioner Replacement

would it still be ok if i put it on tdc first then remove the hydraulic tensioner? would you mine telling me what the hydraulic tensioner, it would really help me understanding it more

That's no problem. Rear Timing Chain Tensioner Replacement

 

[nordictom]

Just a bump for a question.............

Can the rear TC & cassette be replaced with the engine in the vehicle? transmission moved back from the engine, of course.

Thanks,
NT

 

[2000StreetRod]

pulling the transmission

It is possible to replace the rear cassette by pulling the transmission instead of the engine. At least one forum member has done it without using a commercial hydraulic lift. Normally by the time the rear cassette fails the front crankshaft to jackshaft chain tensioner has also failed. There is not much distance between the rear of the engine and the firewall so working space is restricted.

You'll also need the timing tool kit special adapters (1 and 2 below) that allows torquing the right camshaft sprocket retaining bolt to specification. There isn't enough room between the bolt head and the firewall for a normal torque wrench and socket.

Note that a different (lower) torque reading is specified when using the adapter because of the lever arm advantage of the adapter.

If your vehicle has 4WD and a balance shaft then there is also a good chance that the balance shaft chain tensioner has failed.

Normally it is necessary to remove the block cradle (upper reinforcement section) to replace the balance shaft chain tensioner. Removing the cradle is difficult with the engine in the vehicle. The cradle must be aligned with the rear of the block when reinstalled.

 

[nordictom]

Thanks for the reply. Just Curious, did the Forum Member that performed the repair by not pulling the engine post any photo's tip / tricks? When aligning the brace to the block, is there any special tools needed?

BTW, I lucked out, for once........ I found a new in box Matco, Tools Ford Timing chain tool set cheap. it does have all of the tools that your photo shows, plus a few more (they are for 4.6, 4.5 7 6.8 engines).



NT