Loosened Jackshaft bolt w/o Cam locked!

[Mike-in-Maine]

Crap! I'm replacing the Drivers-side cam cartridge, and jackshaft sprockets, tensioners and chains on my 4dr. 2003 Explorer 4.0 SOHC. (got the kit)... The tear down was easy, got everything ready... Unfortunately I made the mistake of NOT double checking what to expect when doing this job.. I didn't get the cam locking tool yet and I wrongly assumed that If I kept everything from moving I could loosen the the jackshaft sprocket bolt to replace that chain and sprocket and then LATER lock the cam sprocket afterwards when I was ready to replace the Cam chain, sprockets and tensioners. WRONG! The second I loosened the Jackshaft sprocket bolt... (*pop*) the drivers side cam relaxed and rotated a bit. On top of this, I had not yet set the crank TDC. I again wrongly assumed I could wait to set to TDC when I was ready to do the cam sprocket. I assumed the jackshaft sprocket and cam sprockets on the jackshaft were keyed. I guess they are not!

So here is my dilemma. (again I know I screwed up by not reading up BEFORE loosening the jackshaft sprocket bolt)... The crank is not at TDC and the drivers side cam has moved slightly. I did carefully remove the jackshaft sprockets and chain and replace in exact position (crank and jackshaft did not move) and have the new jackshaft tensioners in place (old ones were trashed)... but as noted, the cam relaxed and rotated slightly to a comfortable spot when that jackshaft sprocket bolt was loosened. I also seem to understand this now that by loosening the jackshaft sprocket bolt the passenger side cam also is out of time? (i.e. I need to time BOTH cams?)

What to do?? I am so used to conventional OHV single cam engines that this one really caught me in a moment of ignorance.... I suppose the first task is to get to TDC without mashing valves? the drivers side cam sprocket and chain have NOT been removed, nor has the cam sprocket bolt been loosened. Am I correct in thinking that both cams are timed correctly to one another and the only challenge is getting the cran k back in time with the jackshaft (which drives both cam's driven gears)

THANKS to any who choose to help me out here!

 

[rmcknight]

if i were you, id remove the valve followers, thus getting the valves out of harms way. i hope you haven’t damaged one already? then get to TDC, then re-time both cams.

loosening the front jackshaft will effect both cams. ps how did you loosen it without holding the other end of the jackshaft? those bolts are done up very tight and are hard to get loose?

 

[Mike-in-Maine]

Ive been thinking the same thing (relieve the valves so they are all seated)... I havnt rotated the crank so Im not concerned about damaging the valves... but of course the possibility of a cam opening a valve under its spring weight and the valve touching a piston is there... but it wouldn't have much mass or momentum behind it with just a spring...


I have a long socket stuck to one of the flexplate nuts... when you rotate the crank it jams the socket against the starter spacer plate and viola, crank locked... damper bolt came off easy this way also.

So, now my prob is how to set cams once TDC is achieved...

Any other suggestions would be greatly appreciated! (from anyone)

 

[2000StreetRod]

clever idea!

. . . I have a long socket stuck to one of the flexplate nuts... when you rotate the crank it jams the socket against the starter spacer plate and viola, crank locked... damper bolt came off easy this way also. . .

I'll have to investigate your method thoroughly to see if I want to duplicate it.

It takes a special tool to compress the valve springs enough to remove the cam followers:

Removing the camshaft bearing caps is risky because the camshaft journals can jam on the cast bearing surface ends in the head when reinstalling and break the caps. They are not replaceable so that means a new head. I've done it (very carefully) and don't recommend it.

When either (front or rear) jackshaft sprocket retaining bolt is loosened without holding both camshafts in place the camshafts must be retimed because the compressed valve springs will rotate the camshafts via the cam lobes. The resulting cam positions should be for the least total pressure on the cam lobes. Visually confirm that no valve is fully open by observing the positions of the cam lobes and followers.

If you don't allow the valves to retract to their seated position I suggest the following:

Remove all spark plugs to eliminate compression making it easy to detect any crankshaft rotation resistance (piston to valve interference).

It may be possible to rotate thru piston TDC without valve interference if no valve is fully extended in the cylinder approaching TDC. You'll have to very carefully rotate the crankshaft and the camshafts until #1 piston is at TDC on the compression stroke with both camshafts in the correct position (timing slot on end of both camshafts below the axis of the camshaft and parallel to the head surface that mates with the valve cover). If at any time you detect interference between a piston and valve you'll have to adjust the relative positions of the crankshaft to the camshafts to avoid the interference. Knowing the position of pistons approaching TDC while observing the valve positions will help anticipate possible collisions.

Once you achieve approximate correct positions you can install the tools on the crankshaft and the right (passenger side) camshaft and time it. Note: the right camshaft sprocket retaining bolt has left hand threads (loosens clockwise). Then move the tools to the left (driver side) camshaft and time it.

See the following thread for timing the camshafts: SOHC V6 Camshaft Timing

 

[Mike-in-Maine]

Thanks for the helpful info. Here's my latest update...

I removed the passenger side valve cover and that cam is 180 degrees out at TDC. (slot is parallel to head but on upper side of camshaft) the crank key is at 11 oclock so crank is almost at TDC .. exhaust stroke it would seem...

Also, if I remove the jackshaft sprocket from the front can I rotate the pass. side cam independent of the drivers side cam? Not sure if this makes any sense though... I suppose it might be easier to determine cam positions with the crank 180 deg out and tighten the jackshaft sprocket back enough to rotate the crank one full revolution (with cams) so im on the correct TDC.

Removing all the cam followers is the safest route but that tool is expensive and I don't know of any local source around here where I could get one... (in the pic s you see the new jackshaft chain, sprockets and tensioners.. they are only finger tight so I can remove them by hand for the other tasks. (Havnt pulled that pin out on tensioner yet either)

Also, the rear cam chain (pass. side) is rubbing against a post. This cant be good! But I will not be replacing that chain or tensioner due to the labor involved... but that post... I should be able to do something... I am suspecting that a tensioner is gone back there also... see pics showing this and also all the destroyed pieces from from jackshaft tensioner and drivers side cassette (cassette is still in vehicle)

Thoughts?
(BTW, this explorer has 195k miles.. I was surprised at how clean it is inside....)

 

[2000StreetRod]

broken rear cassette

Your right (rear) cassette guide assembly is broken off allowing the chain to slap against the guide upper mounting post. The pieces are probably lodged in the head. Your chain can slip at any time because of inadequate tension. The piston (tensioner) even when fully extended cannot make up for the slack from the missing section of the guide. When the chain slips (typically on deceleration) the amount is frequently enough for the pistons to strike the valves. The only way to replace the cassette is to remove the engine or remove the transmission and work under the vehicle in fairly restricted space. There is no point in replacing the guide mounting bolt. The chain will slip before the bolt fails or wears the chain. I have to leave for a while but I suggest you look thru some of my helpful threads linked in my signature.

 

[Mike-in-Maine]

That's about the worst news I could have got. I proposed the idea to the wife that I could pull the engine and replace the rear chain, tensioner etc, or I could just do the fronts, re assemble and sell the explorer. She said pull it... so pull it is... I suppose most of the "dirty work" is done now, Ive pulled many engines in the past 25 years so this shouldn't be too bad... UGH.... a 1 or 2 weekend job has now become a month or more project... (I work a full day job)

 

[2000StreetRod]

pulling the engine

In my opinion pulling the engine is the best decision. From the photos I see that you have the balance shaft and the smaller diameter curved leaf is probably from a broken balance shaft chain tensioner. In order to replace the entire balance shaft chain tensioner it is necessary to remove the block girdle because the mounting bolts are vertical. It is very difficult to remove the block girdle with the engine in the vehicle because of the front wheel drive components.

Some members who only have front timing chain related failed components have decided to just cut the balance shaft chain and remove it rather than remove the block girdle.

Also, there will be broken components in the oil pump pickup tube screen that may only be removed by turning the screen upside down and shaking them out. There may be pieces stuck behind the jackshaft rear sprocket.

If you hadn't decided to pull the engine I was going to suggest that you install a quality oil filter such as the Mobil M1-301 to remove the metal particles returned to the oil pan from the chain slapping against the guide upper mount post. The particles would still be going thru the oil pump but stopped before the bearings.

Here's a link to my thread on pulling my 2nd generation engine: SOHC V6 Engine Removal Procedure

How many miles are there on the odometer?

By the way, even with the engine out you still will have the problem of getting the camshafts and crankshaft oriented correctly.

 

[rmcknight]

Mike-in-Maine, your 75% of the way through this, dont rebuild the front only to have to do the job again soon after. Also, the engine is going to lock up and you may be in a serious accident as a result.

The poor mans rebuild (where you dont care about your knuckles) and if you can get a helper, you can leave the engine in the car, just push it all the way forward. then you can take off the fly wheel, then you can get to the guide bold (under the cap) - and do the job right.

You can see all the metal grinding off the pin, eventually the grindings, pin, chain and or the timing is going to cause disaster. It must sound like **** as well.

here is my write up on the entire procedure, with pics:
http://sohcreplace.blogspot.com.au/2008/06/1997-2005-4.html

 

[2000StreetRod]

camshaft oilers

Be very careful of the oiling tubes located above each camshaft. Their mounts are flimsy and the tubes are easily damaged if knocked with something.

If before you started the timing chain repair your compression was good and there were no coolant or oil leaks then you should not have to remove the heads.

 

[Mike-in-Maine]

Thanks all.... some info... 188,000 miles (not 195 as stated earlier)... yes the explorer sounded like a total basket case and I "commanded" the the wife and 18 y.o. daughter to drive it ONLY under 2000 rpm. No flogging of throttle, no fast starts, etc... just 2000 rpm or less... it made minimal noise in that range and under those conditions, but anything over about 2000 rpm or any considerable throttle and it was a bag of marbles... idle was scary sounding (frightening actually), even turning off the engine you could hear the residual rattling... so this project was long overdue... it came down to time and $$$ but we're "into it" now... I think my driving like old lady edict paid off though as it didn't blow up...

I agree also, that the last thing id want is to have done this job, front gears only, and then reassemble only to have it break for good a week later.

Also... yes, that small spring definitely came from the balance shaft tensioner, (thanks for the reference picture) I spotted it right under the balance shaft floating in oil... was a bugger to snag and remove... I didn't know where it came from because I had no "before" reference. So.. looks like another item to replace...

And finally... does anyone have a OTC 303-581 compressor I could borrow to get the cam followers out? I cannot believe how insanely expensive this tool is. unreal... I cannot see spending that kind of money on something so simple. Any other methods to remove the followers?

 

[rmcknight]

instead of the tool, you can pull the heads, then it only costs you the head gaskets.
Plus you can clean up the piston tops and check for wear. Time to get those hands dirty......

You can re-use the head bolts - i did...... but you can buy new ones as well to really spoil the car. With the head off - its easier to put the timing gear in as well.

 

[2000StreetRod]

spacer plate?

. . . I have a long socket stuck to one of the flexplate nuts... when you rotate the crank it jams the socket against the starter spacer plate and viola, crank locked... damper bolt came off easy this way also. . .

Is the spacer plate in the photos below what you used to keep the flexplate from rotating?

Mine seems rather flimsy for such a task. Did it distort any?

 

[Mike-in-Maine]

Is the spacer plate in the photos below what you used to keep the flexplate from rotating?

Mine seems rather flimsy for such a task. Did it distort any?

Yes. No visible distortion. Its not really flimsy for a shear/directional type force. It must be .080" steel and that's pretty stout in this aspect.

About the heads, funny, I've been considering this also. Heck, why not pull the heads prior to engine removal? At this point however, a brand new short block might be a better option.

 

[kevinspann]

I'd buy or borrow the timing tools, and just retime the engine. how close is the engine to TDC? I would put the driver's side cam as close as possible to the position it was in before, then put the engine at TDC and check timing/retime both cams.

 

[2000StreetRod]

how much longer?

. . . About the heads, funny, I've been considering this also. Heck, why not pull the heads prior to engine removal? At this point however, a brand new short block might be a better option.

Realistically, how much longer do you think you will keep your already ten+ year old vehicle? A new short block may cost more than the value of the entire vehicle after being repaired. If you take your time and be careful you can work the cams into position relative to the crankshaft without removing the cam followers. According to the book, removing the heads requires replacing the head bolts (expensive) and the gaskets. Initially, you were only interested in achieving a reliable, functional engine.

 

[rmcknight]

Its always best to use new bolts, but you can get away with re-using the old ones. I did and put >100K with no issues at all. I did them up to spec + about a tad more (about +30 deg). It would only add a night to the job to pull the heads and how much as head gaskets? $50? or so? Probably easier than feeling the engine around, and im not 100% sure he hasn't damaged a valve already? When the cam turns under the springs, it really turns with force and momentum.

Also, he needs to rotate one of the cams 180 deg, to its original position, that may be difficult with the head on, and you cant easily feel that around?

 

[Mike-in-Maine]

I'll be trying the "careful and slow" crank rotation. If anyone has a picture of cam positions (approx.) with the crank at top of exhaust stroke (360 out) it would be helpful.. (ya, I know that's not an easy request)... So I will tighten the jackshaft bolt and see what we get... as I said I havnt moved the crank, just the cams relaxed when the bolt was loosened.

I will be pulling the block, pulling the pan, cleaning out oil pickup , and not removing the heads. I'll be unbolting the exhaust manifolds from heads for removal, so they will stay in car.

(BTW, whats the deal with the spark plug wires??? I can't get those things off without fear of ripping them to pieces!!)

 

[2000StreetRod]

removing exhaust manifolds

Many members use the exhaust manifolds when lifting the engine in and out. I used them for removal but not for installation.

If you haven't moved the crankshaft and only the left camshaft rotated from spring pressure when the jackshaft sprocket retaining bolt was loosened the camshafts could not be 180 degrees out of sync. The camshaft should not have rotated more than 60 degrees. Are you sure the right camshaft didn't also rotate? I suggest attempting to rotate the camshaft back to its correct position relative to the other camshaft, then tightening the jackshaft sprocket retaining bolt and then rotate the crankshaft with camshafts to the correct position.

You will have to get the camshafts and crankshaft close to proper alignment before removing the engine. The crankshaft must be rotated to disconnect the flexplate from the torque converter. Or, you could leave it connected, and pull the engine with the torque converter attached to the flexplate.

 

[Mike-in-Maine]

If you haven't moved the crankshaft and only the left camshaft rotated from spring pressure when the jackshaft sprocket retaining bolt was loosened the camshafts could not be 180 degrees out of sync. The camshaft should not have rotated more than 60 degrees. Are you sure the right camshaft didn't also rotate? I suggest attempting to rotate the camshaft back to its correct position relative to the other camshaft, then tightening the jackshaft sprocket retaining bolt and then rotate the crankshaft with camshafts to the correct position.

You will have to get the camshafts and crankshaft close to proper alignment before removing the engine. The crankshaft must be rotated to disconnect the flexplate from the torque converter. Or, you could leave it connected, and pull the engine with the torque converter attached to the flexplate.

The pass. side camshaft is not 180 out of sync, but just 180 out from where it should be when crank is at #1 TDC for setting timing... (NOTE: the crank is *not* currently at the right TDC, its 11 o'clock on the #1 exhaust stroke)

What happened as I observed is as follows: Initially, the passenger-side valve cover was still on, drivers side valve cover off, Cam bolt untouched, crank at 11 oclock on the exhaust stroke, jackshaft sprocket bolt was loosened and drivers side cam was observed to *pop* slightly to its relaxed position. passenger side cam was not observed due to valve cover still being on. From that point I removed the passenger side valve cover and the rest is as you see in the above pictures.

My Question is- could the passenger side cam have also moved to a relaxed postion just as the drivers side cam did? If not then you are right and I just have to adjust the drivers side cam slightly, but I cannot tell where or how much without a reference photo of the proper cam slot orientations with the crank at 11 oclock on the exhaust stroke.

And yes, it had occurred to me that I will have to get this sorted out before I can unbolt the flexplate. Thanks for the continued discussion everyone!