How to: Rear Timing Chain Tensioner Replacement

[hellah fresh]

Hello! This is a great write up! And also i found this thread on google. I have the same problem with my 01 explorer where my cassette chain tensioner plastic broke. I just need to replace the plastic chain guide. can this be done with out taking the engine out? My main concern is that i dont want to remove the head just to change out the tensoner. So so i need to take off the cams also to do this?

 

[kdbstl]

ring install

Thanks to Dale for this thread and I apologize for completely missing the part number in this thread. I got on here after smelling then seeing oil from the tensioner leaking on my exhaust manifold about two months after installing the tensioner w/out a washer. Got the washer from the dealer in hand and noticed the cupping shape. I'm pretty sure that the way I will install it is correct but I wanted to bring it up for discussion. Maybe I missed it in the thread. Regardless, I turned 200K last week and am shooting for 225 before I have to tear anything apart.

 

[2000StreetRod]

Caution & PNs

I didn't notice my compression ring being cupped when new. Please note the caution below.

CAUTION: McSlug has provided an excellent tip regarding the installation of the new tensioner. It is very important to ensure the washer/compression ring (if used) on the tensioner is centered when the hex head face contacts the head. If the compression ring is not centered then oil will leak profusely no matter how tight the tensioner. Applying a small amount of gasket sealer between the compression ring and the tensioner face will keep the ring in the correct position.

I have posted timing chain related part numbers and try to keep them current in the following post: http://www.explorerforum.com/forums/showpost.php?p=2420031&postcount=2

 

[hellah fresh]

I finished installing the cassette tensioner without removing the cylinder head. What i did was remove the valve covers and then we had to drop the transmission to access that rear bolt that was holding the tensioner. When we dropped the tranny it made the work so much easier.

 

[Orleans]

These two brands are reliable? Does anyone know or recommend?

 

[2000StreetRod]

timing chain parts source thread

These two brands are reliable? Does anyone know or recommend?

I've started a thread about potential sources of timing chain parts: SOHC V6 Timing Chain Parts Sources

 

[Sedition]

Still in time?

I was wondering if I would have to retime the passenger side cam with the chain being this lose.

I was thinking of just turning the crank by hand counter clock wise a little as the tensioner side is ok, Its just the guide that needs replacing.

Normally the truck feels in time unless its up over 5000rpm, or i have my right boot buried in the carpet on the beach. Then it just seems to be a little out.

I thank you in advance for your replies.

 

[Sedition]

Maybe I can find a sprocket or a guide from some where else and attach it to that bolt to push the chain back into shape, correcting timing.

All other chains are tight.

I just need a quick fix for now until I can set up my garage properly and get an engine hoist and the parts required. As this truck is my daily driver.

Any thoughts on this at all would be great.

 

[Sedition]

Advance timing

So, I have decided to advance the timing on the right cam rather then put foreign objects in my engine to deflect chain into position.

I'm thinking of rolling the cams around till they sit without pressure from valve springs trying to turn them.
Then using a flat blade screw driver to put all the slack on the opposite side of the chain tensioner.
After ensuring both cams are in time relative to each other, I shall loosen cam bolt, wind the sprocket back till the chain is tight accross the top side, then re tighten the cam bolt to spec.

What I am hoping to achieve with this mod is.
As the engine starts turning, instead of first pulling up the slack in my rear chain and then rotating my right cam shaft slightly later then normal. Everything will be in time again.

Ill probably do this tomorrow as I am too tired at the moment and dont want to make any silly mistakes.

 

[2000StreetRod]

correcting cam timing

So, I have decided to advance the timing on the right cam rather then put foreign objects in my engine to deflect chain into position.

I'm thinking of rolling the cams around till they sit without pressure from valve springs trying to turn them.
Then using a flat blade screw driver to put all the slack on the opposite side of the chain tensioner.
After ensuring both cams are in time relative to each other, I shall loosen cam bolt, wind the sprocket back till the chain is tight accross the top side, then re tighten the cam bolt to spec.

What I am hoping to achieve with this mod is.
As the engine starts turning, instead of first pulling up the slack in my rear chain and then rotating my right cam shaft slightly later then normal. Everything will be in time again. . .

Without the traction side guide the camshaft is lagging some degrees behind the crankshaft. It would be good to estimate how many crankshaft degrees the camshaft is lagging. One way is to align the camshaft timing slot, hold it in position, and then turn the crankshaft until the chain is taught on the traction side. The number of degrees past TDC indicated on the harmonic balancer indicates the timing error. It may not be enough to significantly affect performance.

If you decide to compensate for the error it is only necessary to loosen the camshaft sprocket retaining bolt, position the crankshaft at TDC, align the camshaft timing slot while the chain is taught, then tighten the camshaft sprocket retaining bolt. Remember that the passenger side camshaft sprocket retaining bolt is a left hand thread (tightens clockwise).

 

[Sedition]

Classic signs

classic signs that lead me follow this avenue are:

1- Oil pressure seems a little higher than usual, just noticing on dash gauge.

2- Deminished performance. Only slightly noticible when truck is under load or operating at over 5000rpm when overtaking under light load.

3- Right bank exhaust seems excessively hot when truck is under load for sustained periods, such as driving in soft sand. I jumped out to let the tyres down a little more, noticing only the right bank cat was smoking.

4- Idle seems a little lower than usual when engine is warm, not by much, mabee 25 rpm or so. If you didnt know this vehicle you would not notice.


I will re install the front timing cover and harmonic balancer once my wife comes home from work (my 2 year old daughter likes to help otherwise) and calculate exactly how much the timing is off.


Oh, and by the way. Thanks for that info above.

 

[2000StreetRod]

take it easy

classic signs that lead me follow this avenue are:
. . . 2- Deminished performance. Only slightly noticible when truck is under load or operating at over 5000rpm when overtaking under light load.

3- Right bank exhaust seems excessively hot when truck is under load for sustained periods, such as driving in soft sand. I jumped out to let the tyres down a little more, noticing only the right bank cat was smoking. . .

I suggest that you take it easy until you have a chance to replace the rear cassette. With the guide broken off there is a greater probability that the timing chain will slip. Slippage is more likely to occur when the oil pressure is low (during engine start) and when the engine is rapidly decelerating (slack increases on the traction side).

 

[Sedition]

Out of time

So It turns out my right cam shaft is 12 degrees out of time. I used the method Mentioned above, holding cam shaft with vice grips and the edge of the head as I do not have timing tools.

I also noticed that when the crank shaft was at TDC, the difference in measurment in millimeters from the bottom of the hex wrench, to the top of the head was the amount of degrees that shaft was out in relation to the crank, according to the markings on the crank.

Low side= 33mm
High side= 45mm
difference in measurement = 12mm

This picture shows where the right camshaft sits when the harmonic balancer shows TDC



I believe having the timing this far out may very well be causing my problems. I will tighten the chain, put her back together and see how she runs.

In order to tighten the chain, I will hold the right camshaft at TDC then roll the crank back so the rear timing chain slackens off on the non-traction side and just begins to compress the tensioner (easily visable) on the traction side of the timing chain.

I will then attempt to loosen the camshaft bolt by reaching from behind the other side of then engine with a torque wrench as this looks like the only option that wont take the skin off my knuckles as this is a REALLY tight space.

 

[2000StreetRod]

wrong position

Your photo of the harmonic balancer shows the pointer at about 12 degrees before TDC (crankshaft rotates clockwise). Your photo of the camshaft shows the timing notch needs to rotate more clockwise to be in the correct timing position. The photos do not indicate that the camshaft is lagging the crankshaft.

Rotate the crankshaft until the timing notch on the camshaft is parallel to the head surface that mates with the valve cover. Then see if the front timing cover pointer indicates after TDC on the harmonic balancer.

 

[Sedition]

Sorry I put the wrong photo in the above post, It is corrected now. Now it shows the timing out the correct way. The original picture that was posted shows the crank once rolled back to slacken off the chain.

Undoing the Right camshaft bolt whilst the engine is in the car is VERY difficult. I had to give up on it last night and hit the sack, after posting the wrong picture!

 

[Sedition]

Done!, for now.....

I got my SOHC back together with both camshafts and crank all timed perfectly together at TDC, with the rear chain tight accross the tension side of the chain. So I start her up, from the moment I turned the key I could hear the chain chattering back and forth inside and really not sounding good, kinda tractory even.

I immediately turned the engine off and set to work stripping off the right valve cover. After checking for damage and long periods of trying to visualise what was happening I then dicided to set the right camshaft "late" by 5 degrees. (was originally behind by 12 or so)

This time she started perfectly and runs smoothly with a very noticble improvement in torque. Hell Yeah! The oil pressure gauge now appears to be in a more "normal" position.

I'm thinking with having the camshaft come in just a little late is what was required to hold my guideless chain in tension "properly" and not shake about. I am unable to prove why but perhaps when it was at TDC the cam would roll ahead by valve spring pressure or something of the sort.

This is ment to be a quick fix for a shattered rear chain guide until I can aquire some engine pulling equipment. I think it is worth while to perform if you miss having your performance when you need it most.

My SOHC engine has always treated me well. She gets fresh oil every 3000 miles. Appart from regular maintennance she has only ever needed the 00m12 fix about a year ago due to the usual reasons. (Cold start / slight front chain rattle)

I shattered my rear guide after I hydrolocked my engine when I was caught in a flood. She got me out of harms way then stalled 30 feet later. I immediatly knew I had hydrolocked my Explorer as i had seen this before and I could feel her chewing water underfoot on the way out of the flood water.

After the weather cleared I had my wife flat tow me home with her Sportage.:roll:

 

[bigredscowboy]

streetrod, did you install metal o-rings on your tensioners? I noticed where you said they might cover the oil hole completely... There wasn't one on either of my tensioners before but only got one in the chain kit. Motor needs to go in today and deciding whether to go to the dealer to get one for $10

 

[2000StreetRod]

tensioner compression rings

streetrod, did you install metal o-rings on your tensioners? I noticed where you said they might cover the oil hole completely... There wasn't one on either of my tensioners before but only got one in the chain kit. Motor needs to go in today and deciding whether to go to the dealer to get one for $10

I installed a compression ring on the left and right tensioners. I decided they would have a better chance of sealing (no oil leak). They have a tendency to slip down when installing. You can use gasket sealer or wheel bearing grease to keep them in place. Many members have had bad leaks after installation because they slipped out of position before being tightened. If you use the ones designed for the purpose (very thin) they don't block the oil port in the tensioner.

 

[ex0r]

In the picture where you show the tensioner, the sprockets, the chain, and the guide for the driver side cam, that little butterfly shaped piece (I am assuming is the cam chain guide), that part broke on mine and busted a hole in my valve cover. How do I replace just that part (Does it require taking the timing cover off, or no?), and is it possible to replace just that part without getting the entire timing assembly ?

 

[2000StreetRod]

butterfly?

Are you referring to the photo below?

If so, and some part of the plastic (guide assembly) is broken then yes, you must remove the front timing cover to replace it. The guide assembly is no longer available from Ford as an individual part. You have to purchase the entire cassette (guide assembly, sprockets and chain).