02 4.0l XLT Rear cam sprocket mount separating from rest of cam!!

[Boricua8412]

Has anyone ever heard of the cam sprocket mount separating from the rest of the cam? From every picture ive seen on here the mount should be almost flush to the bearing cap. I can see about 1/16" to 1/8"of the splines that mate it to the camshaft. Its bad enough that my valve cover was a pain to get off and will not go back on without possibly hammering on it. There are rub marks on both the chain and the timing slot sides of the valve cover. Am i safe to assume this camshaft is shot? Could it have come out far enough to cause the mount inside the shaft rotate causing timing to be off? I found this after i had timed the engine "succesfully". Started her up and heard what sounded like hydraulic lifter tapping on the opposite bank. I shut the engine down after about 2 minutes of hearing the tapping. I started it back up the next morning after researching the possible causes of the tapping sound. Only ran for about 5 seconds but this time no tapping for the first 3 to 4 seconds. As quickly as it started tapping again the engine died and has not started back up since. I tried everything. Right side timing is now off but left is dead on. Chain didnt jump teeth from what i can tell. Tensiors appear to be doing thier job. Guides are new and installed correctly. Oh and i did use the OTC 6488 Tool Kit. Any help will be much apreciated.

Also: Thank you to everyone for all the usefull information i have found over the past couple of weeks. This site is Awesome

Here is a picture of the damage in case anyone ever comes across something like this.

I replaced the Camshaft already wasnt the problem i was having but definately a problem that needed fixed.

those splines are not supposed to be seen, nor should the be a gap between the bearingcap and sproket mount. im still stumped as to how this happened.

 

[Boricua8412]

im sorry about the huge picture, im still figuring this all out.

 

[Boricua8412]

I beleive i have figured out what my problem is... for those interested
The tapping sound i heard afterer i started the engine the first time was most likely a hydraulic lifter that hadnt recieved oil yet. After i replaced the camshaft and put reassblemed/timed the engine properly. I started her back up and ran great for about two minutes when the exact same this as before happend ( loud tapping followed by engine shut down never to start up again) Well after disasembly yet again. Much to my surprise the new camshaft (junkyard)now looked exactly as the one in the picture.i now had three bent exhaust valves (exactly as when i started the first time) Removed the new cam and did some digging... i was able to secure the camshaft in a vise while attemping to turn the the end that the sprocket mounts to. It turned as if the splines had come out far enough to become disengaged from the rest of the cam.. So i can only assume the the cylinder head is shot (warped perhaps) and is causing the camshaft to either seize or slow down wile the engine is running thus causing the chain to vibrate enough to back out the splined portion until it ls far enough to spin and lose timing, bend valves etc...i will be ordering a new cylinder head and getting another camshaft with followers from the junkyard and everything will be good to go. Will post again if all is successful.

 

[2000StreetRod]

thrust bearing cap?

It is important to install the bearing caps in the same location they were removed from. There are no bearing inserts - the head cam bore and the cap bore provide the bearing surface. I can't remember if the caps are number stamped. One of them acts as a thrust bearing (different from the other three).

The hydraulic lash adjusters will drain during the time of an engine rebuild or head work. The ones that drain will be noisy on engine start. It can take up to 20 minutes of driving at engine mid-range for them to refill and quiet down.

 

[Boricua8412]

2000StreetRod you are dead on. After looking over everything again i looked at the bearing caps and theyvare un fact stamped. R1 R2 R3 and R4. I set them aside in the order they came out not realising that they were wrong all along. Will this head need to be redone since the motor has ran at least twice with the caps in the wrong position... i can see rub marks on at least two of them?

 

[2000StreetRod]

no bearing inserts

Since there are no bearing inserts any wear resulting in excess clearance can only be resolved by replacing the head. The head and cap is bored to match the camshaft journals. I suggest using plastigage with the caps correctly installed to measure the clearance. Do not remove all of the caps at the same time to get them to the correct positions if you don't have the special valve spring compressor.

It is easy to break the caps when installing them with the cam followers in place because the valve spring pressure prevents aligning the axis of the camshaft with the axis of the bore. The caps bind and break when tightened.

If the caps are not scored badly and the clearance meets specification when correctly installed I would drive it that way since the engine only ran for a brief period of time.

Camshaft journal-to-bearing (oil) clearance service limit: 0.006 inch

 

[Boricua8412]

Will check the clearance first thing.. thank you for your
suggestions. Very good information.

 

[DeCaff2007]

It can take up to 20 minutes of driving at engine mid-range for them to refill and quiet down.

Good to know! I have just gotten done with a spiel, myself, of putting new heads on my 02 Ranger 4.0L OMFG what a PITA!

Since I'm now 100% sure that everything is put together and timed correctly, I'll be listening for valve train noise and won't panic just yet, lol.

 

[Boricua8412]

Well... i am at it again. I reinstalled everything after making sure the bearing caps were still ok and in the right position. I got it started up right off the bat and this time the engine ran great no issues for about 5 minutes. No tapping, no misses, no CEL nothing all seemed to be in order. well after about 6 or 7 minutes i felt the engine start to lose compression and i heard the dreaded sound of the pistons smacking the valves on the right bank once again followed by the engine stalling and never firing back up. I havent torn it back apart yet but after lining up the 0 mark on the Balancer i took a peak through the oil filler port and could see the timing slots for the right camshaft were way off. I can bet any amount that the rear sprocket is just as in the picture above for the thrid time. Now im almost certain my problem has to do with either the rear jackshaft sprocket, front jackshaft sprocket or oil delivery to the right camshaft. I include oil delivery because as soon as it stalled i tried to rotate the engine by hand and it was very tight but then loosened after a while. Once i pull the valve cover back off i will see what it looks like in there as to how much oil may have splashed around in there. if it looks drier that it should... Where should i begin looking for blockage? Could the camshaft bearing area not be receiving enough oil or any at all for that matter? Any other suggestions or possible causes? Also, Left Timing is still intact i removed the camshaft sensor and can see the notch where it is supposed to be this was the same in all other occurances.

 

[2000StreetRod]

What a shame!

I admire your patience and persistence. Did your right camshaft sprocket problems begin immediately after you replaced your timing chain related components? What was the reason you replaced the components?

I think it is possible to install the sprocket facing in the wrong direction. The sprocket is offset from the hub so if installed incorrectly the chain would be pulling the sprocket/hub out of position. Below are two examples showing the correct assembly positions.

 

[Boricua8412]

To answer your questions, I purchased the truck with bent valves, knowing that the previous owner had attempted to time it as well and ended up with the same result as i did with the sprocket hub. So at least both cassettes are new. I dont really know if the primary chain and sprockets are new as i haven't taken the front cover off yet since i was trying to stay away from taking the balancer off( from what i've read it can be dificult) but i suspect they are new as well. The previous owner told me the original motor was blown so he pieced together the block and cylinder heads from junkyard engines. You say the sprockets can be installed backwards and cause the chain to pull the sprocket. Do you mean the camshaft or jackshaft sprockets? I know the camshaft sprockets are installed correctly as i made sure of it while timing it on my first attempt.

 

[Boricua8412]

And thank you 2000StreetRod for taking time to help me figure this out. Much appreicated..

 

[boominXplorer]

What are your torquing that rear camshaft bolt to? Was it already loose when you dissembled it?

 

[2000StreetRod]

camshaft sprocket

I was referring to the camshaft sprocket which is why I included the photos. The crankshaft sprocket can also be installed facing the wrong way but then the crankshaft balancer will not seat properly. Yes, many members have broken their puller side bolts when trying to remove the balancer. That's because a standard puller center bolt is too large to fit in the hole and press against the crankshaft end. The bolt is just pressing against the balancer attempting to pull it apart. The balancer center section is very strong so the small bolts break first.

You have a difficult situation not knowing exactly how the previous owner assembled the engine.

Edit: If you PM me your email address I'll send you a copy of the SOHC V6 assembly instructions that include a lot of drawings. Maybe looking thru them you'll notice something on the engine that doesn't look correct.

 

[Boricua8412]

Torque applied on the rear bolt was 45ft lbs, Using the special tool. The bolt was tight everytime i removed it.

 

[Boricua8412]

Found the culprit

Pulled the motor today and found the what was causing the sprocket hub to back out.
As you can see by the photo the sprocket was installed backwards...yes backwards the dots go towards the engine, on the reverse side it has the slots for the Ford sprocket holder tool. After removing the bolt, sprocket and the beveled bushing sorta deal that sits in there you can clearly see the the sprocket was not only not centered on the jackshaft but was also sitting crooked after being torqued down. You can see in the picture how far off center the bolts sits. I am glad i took the time to track this sucker down instead of just getting another engine as i already have new timing components. Saved my self some cash but man has it been a pain in the butt. 3 Camshafts and 9 exhaust valves later i will finally get this truck on the road. Depending on the weather hopefully will have it done in the next few weeks.

Thanks 2000StreetRod your help

A little history on the truck before i get bashed for this. I bought the truck off a guy cheap because he tried to put together a motor for it and once he bent the valves he immidiately gave up and decided to sell the truck.
Well if he hadnt of installed the sprocket backwards it would of ran fine for him and would never have sold it to me so in a way im glad he did. i just wish i would have caught it sooner. Hope this info can help someone in the future though i dont see this happening very often.

 

[2000StreetRod]

Nice catch!

As I mentioned earlier, it's always difficult when following someone else's work with questionable experience. I purchased my 1996 Volvo turbo wagon from a owner who paid $600 to a mechanic who worked on antique trucks to fix it after it quit running. The owner and the mechanic both gave up on it and it sat in a field for a year before he sold it to me for $825. I bought it just for the challenge and because I've never had a turbo engine vehicle. A large part of the engine external components were in a box on the floor behind the front seat. It had a bad fuel pump, the camshaft timing was off and there was no ignition. I've been driving it for about three years. It has good power and gets decent gas mileage. It's just too low and hard to get in and out of for me at the age of almost 68. I am ready to sell it and buy a 2000 4 door Explorer as a backup to my Sport and my wife's vehicle.

I applaud you for digging into the engine to find the source of your problem! I bet your hydraulic tensioner was really getting a workout with that offset jackshaft rear sprocket. Here's a photo of mine.

And this blurry photo (too close with the camera) shows a piece of my rear cassette that was lodged behind the sprocket.

 

[Billy5076]

Looks like a picture of my cam!

Sorry to jump in on an old thread, but this is the only one I've found concerning my issue. I have this exact problem, and I'm hoping you can confirm that the backwards sprocket was the root cause of the cam coming apart. I am doing this with the engine in the chassis, and don't want to pull the transmission a third time. I am pretty sure my balance shaft is out of time. Could that cause the right cam to separate, too?

 

[Jay_Lael]

Hello to the group. I am also experiencing this horrendous problem. The truck was running fine, except it needed head gaskets, due to HCs in the cooling system, so I decided to go ahead and pull out the engine, and I had the heads rebuilt by a local machine shop, and replaced all the timing components. As this thread indicates the bottom sprocket for the RH timing chain was installed flipped over, and as described it ran flawlessly for about two minutes, them made a sound like a diesel engine for a second then stopped cold. Inside there were three bent exhaust valves on the rh bank, and the cam sprocket flange was pulled off the rh camshaft, exposing the splines. The camshaft is shifted ahead about half an inch. I flowed green Loctite into the splined area and used the press to put the flange back on the cam. With the offending sprocket now installed correctly, and the cam caps all sorted properly from the start, it has happened again. I am in the process of pulling the engine for the third time, and really need any helpful info. What is causing this to re-occur? Help please!

 

[Jay_Lael]

It's been over a week, so I guess there will be no helpful replies. I did successfully fix the Explorer, so I figured I would write down a few notes in case some other poor fool has the same problem.
The timing chain cassette came pre-assembled and was zip tied together. Problem is, the lower sprocket is flipped over in the box, or at least this one was. Even though I read the book, and studied to old parts, it must have been a Monday, because I didn't catch it. This is where the horror started for me, that lasted almost a full week of full time wrenching on the same truck.
On reassembling the truck the first time, I discovered the problem after it ran for a few minutes, then shut off with three bent exhaust valves on the right bank. At this point, a few new problems reared their ugly heads. One of them was that once the lower sprocket has been installed and tightened while flipped over, the recessed socket looking surface of that sprocket does damage to the end of the jackshaft, which actually has a sleeve on the end of it, which mates up to the sprocket's flat surface when assembled right. The sleeve had been buggered a little bit, but I simply flipped the sprocket over the right way, and tightened the bolt with a 3/8" impact, pretty tight.
As mentioned before, I loctited the splined camshaft stub and pressed it back into the end of the camshaft, which is built on a hollow tube. Even though the lower right cam sprocket had been tightened with an impact, it came loose before I could get all the torque converter nuts all put on, which saved me from having another set of bent valves, but I did have to pull the engine back out to tighten the lower sprocket bolt again, this time with a breaker bar, as per the manual. This never came loose again.
As soon as I got it reassembled a third time, and started it up, the engine ran flawlessly for about two minutes, then the camshaft flange came off again, thus bending the new valves.
After sleeping on it, I was inspired to do a lasting fix to the right camshaft, which I hope I never see again.
I knocked the splined cam stub out of the camshaft, and drilled a hole in the end of it, and tapped it to 3/8" x 24, then carefully re established the splines with a cold chisel, as they had been smoothed out a bit by prior events. I then attached a length of 3/8" threaded rod with Loctite, and a jam nut, for additional security, and set this aside.
Careful measurements revealed there is not much room inside the valve cover at the front end of the camshaft, so I had to cut off the end of the camshaft just enough to allow room for the new bushing and still have room for the 3/8 nut to securely bolt the camshaft together permanently. This eliminated the slots for the alignment tool, but by this time, I had learned how to line everything up perfectly without the tools anyway. I then slid this assembly into the camshaft tube, seating it fully with a shop press, loctited the nut after torqueing it pretty damn tight, then staked the end of the rod with a sharp punch.
As you can imagine, I was trembling hen I hit the key for the test fire, on the fourth try.
The truck is finally back on the road, and everything seems to be fine.
I hope and pray that this never happens to you, but if it does, I hope others might learn what not to do, before the job goes south this badly.
Jay