• Register Today It's free! This box and some ads will disappear once registered!

How to: SOHC V6 Timing Chain Inspection & Repair

laker82

Member
Joined
March 28, 2015
Messages
39
Reaction score
2
Year, Model & Trim Level
02 explorer xlt
So I took off the balance shaft sprocket to change the tensioner because I couldn't get the bolts out of the tensioner mount. The sprocket is funky looking it has half a key in it that doesn't engage with the keyway on the sprocket. I'm assuming that this setup is just like the cams where the timing chains position is irrelevant as long as the balance shaft relationship to TDC is correct. Has anyone messed with these before? If so what's the story with the funky gear who's key doesn't engage the shaft.

Thanks

J

Did you get this resolved? The balance shaft crankside gear is keyed to the crank with a larger key behind the smaller keyed gear 2000StreetRod is showing.

2000StreetRod, thanks for fixing my error, completely forgot doing the balance shaft timing step.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




laker82

Member
Joined
March 28, 2015
Messages
39
Reaction score
2
Year, Model & Trim Level
02 explorer xlt
Something that has been kicking around in my head. ( well one of many) Post #10 shows a chain to avoid the special tool that holds the crank to torgue the bolt shown in 10. That is a 2 step torque the 2nd step is an additional 90 degree turn. The shaft is the "nut", couldn't the shaft turn with the bolt and you really do not tighten the 90 degree turn? Special tool or chain you really do not hold the shaft at all, it is just friction holding the shaft from turning. You would not know if it did or not. I think I will mark the rear end of the shaft just to make sure.
 




2000StreetRod

Staff member
Moderator
Elite Explorer
Joined
May 26, 2009
Messages
10,595
Reaction score
254
City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
good observation!

That's a good observation laker82 and I have a possible explanation. I suspect the contact surface area between the sprocket retaining bolt and the sprocket is less than the contact surface area between the sprocket and the hub. So the bolt turns before the sprocket or the jackshaft. However, if the threads of the sprocket retaining bolt were mangled then the jackshaft might rotate with the bolt head. There's a limit on how much the jackshaft can rotate because of the "flats" on the hub.
JacshaftThrustPlate.jpg

It's always a good idea to check the camshaft timing after everything is tight before installing the valve covers.
cam1.jpg
 




ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
Measure twice cut once

Soooooo when I changed the crankshaft to jackshaft chain and gears I put the crank gear on backwards. I want you all to check my train of thought here. In order to get the chain off to flip the sprocket around I'm going to have to remove the jack shaft bolt. This would mean I would have to re-time at least the left bank. Now my thought is this, if i use the timing tools to hold the cams stationary (the cam holding tool on the right bank and the sprocket holding tool on the left) then I would be able to break the front jackshaft bolt loose, flip the sprocket and not lose the timing of the cams. Sound right? It makes sense in my mind but again i'm the jacka$$ that put the sprocket on incorrectly to begin with.

Thoughts, questions, concerns?

Measure twice cut once

JA
 








ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
Tensioner tool

So If i use this method of holding the cams in position while I loosen the jack shaft bolt, how do I keep the tensioners tight when I go to tighten the jack shaft as I will only have one tensioner tool? Or will it really matter? I was thinking of using it on the left hand side for sure as this is directly bolted together with the jack shaft.

Maybe I have to make a tensioner tool out of one of the old tensioners

Thoughts?

J
 




2000StreetRod

Staff member
Moderator
Elite Explorer
Joined
May 26, 2009
Messages
10,595
Reaction score
254
City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
keeping things in place

The sprocket holding tool installed on the driver (left) side will prevent any torque from being applied to the camshaft when the front jackshaft sprocket is loosened or tightened. The camshaft holding tool installed on the passenger (right) side will prevent the camshaft from rotating but not prevent the jackshaft from rotating to relieve the tension from the spring/hydraulic tensioner. The only way to prevent the jackshaft from rotating when the front sprocket bolt is loose is by replacing the rear tensioner with the precision tensioner in the timing kit. Even then I wouldn't trust the process. That must be why the jackshaft sprocket bolts (front and rear) are always tightened before the camshaft sprocket bolts. The safest thing is to follow the written procedure and retime the camshafts after tightening the front sprocket bolt.
 




ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
Might as well

The safest thing is to follow the written procedure and retime the camshafts after tightening the front sprocket bolt.

Yeah this is what I decided last night. No reason not to do it correctly since I have it all apart again. No sense in bending a valve now.

Thanks

J
 




ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
The saga continues

Put it back together, ran fine for 2 days, backed into the garage last night and with the echo it sounds like a diesel. More specifically an old Mercedes diesel. Last night I took the belt off and ran it to make sure it wasn't coming from something in the serpentine. It's not. It's coming from the left front valve cover. It's a rhythmic knocking that changes with engine speed. I can't think of anything that would make this noise other then a hung up valve or something. It runs fine has power, just making a funny noise.

Any ideas?

J
 




2000StreetRod

Staff member
Moderator
Elite Explorer
Joined
May 26, 2009
Messages
10,595
Reaction score
254
City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
still the original problem?

Just to recap, you found and replaced a broken primary chain tensioner and rear cassette guide but still have pretty much the same noise that originally prompted you to inspect the engine. But after the repairs the engine ran quietly for two days. Perhaps you have a failed hydraulic lash adjuster resulting in excess clearance in the camshaft to valve stem path. Does your 2003 engine have the oiler tube above the camshaft like the older engines? The tube mounts are easily broken if bumped hard.
 




ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
Who knows

Just to recap, you found and replaced a broken primary chain tensioner and rear cassette guide but still have pretty much the same noise that originally prompted you to inspect the engine. But after the repairs the engine ran quietly for two days. Perhaps you have a failed hydraulic lash adjuster resulting in excess clearance in the camshaft to valve stem path. Does your 2003 engine have the oiler tube above the camshaft like the older engines? The tube mounts are easily broken if bumped hard.

Yes I found a failed main tensioner and a broken rear cassette guide. I replaced the main chain, sprockets, tensioner, and guide. I also replaced the front and rear cassettes. Initially I put the crank sprocket on backwards which would not let the balancer fully seat. I took the timing cover off and flipped the sprocket. I retimed both cams and reassembled. I drove it and on the second day (less than 100 miles) I have a new noise (different from the initial noise that led me to the broken cassette) that sounds more like a diesel knock. I disconnected the serpentine to ensure that it was indeed coming from the motor and it sounds like it is coming from the left front camshaft in the area of the timing chain. It does have the oil tube mounted on the cam bearing caps and it didn't appear damaged when I put it back together. I have yet to pull the valve cover to inspect it yet as it has been such a royal pain in the A$$ that I need to walk away from it for a few days. The noise has stayed the same for the last two days. I'm thinking maybe something got in the motor when I had the motor apart and has one of the lash adjusters jammed or something. I think I'm going to run it until it gives me more clues as to what it is.
 




laker82

Member
Joined
March 28, 2015
Messages
39
Reaction score
2
Year, Model & Trim Level
02 explorer xlt
Injector dripping from dirt that got in the line when apart?
Any computer codes?
All the time or just some times?
 




ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
No lights on the dash didn't run a code reader on it. Got worse as the engine warmed up. Now seems to have quieted down, almost gone. Did the chain have to break in maybe?

I'm just going to keep driving it and see what happens

J
 




laker82

Member
Joined
March 28, 2015
Messages
39
Reaction score
2
Year, Model & Trim Level
02 explorer xlt
Slug break loose it the tensioner oil supply passage?
 








Drewmcg

Elite Explorer
Joined
August 27, 2015
Messages
731
Reaction score
91
Location
Michigan
City, State
Ann Arbor, MI
Year, Model & Trim Level
2010 XLT 4WD
2002 XLS 2WD
Slug break loose it the tensioner oil supply passage?

I like this thought. The oil port on the top (near the exterior surface) of the LH tensioner is (a) very, very small; and (b) very near the exterior surface of the engine. This is why the washers for the tensioners are so very thin. I tried (preemptively) using a rubber-backed washer that another poster on this forum had used to stop an oil dribble. Big mistake. I didn't like the way the tensioner was sitting in the head (off kilter) after I torqued it down. So I backed it out to replace with the thin washer, and found that rubber from the non-oem washer had plugged that hole. Boy was I glad I decided to go back to the oem washer!

I could easily see some debris or sludge blocking that tiny hole, impeding pressurizing of the LH tensioner, and causing it not to tension that timing chain as it should (leading to noise). Plus, it should be relatively easy to take this out and check/clean it (no need to remove the valve cover).

You might need to remove the temperature sensor on the top of the upper thermostat housing (just don't lose the clip that holds it in). Its not hard. Good luck.
 




laker82

Member
Joined
March 28, 2015
Messages
39
Reaction score
2
Year, Model & Trim Level
02 explorer xlt
Make that sludge. Love auto-correct.
 




ef2764

Member
Joined
September 20, 2015
Messages
25
Reaction score
0
City, State
St. Louis Missouri
Year, Model & Trim Level
2003 Ford Explorer
The noise is coming and going with no rhyme or reason. Maybe there is a blockage to the front tensioner. I will check it. I'm just glad it is running again.
 




damienlike

Member
Joined
September 16, 2010
Messages
15
Reaction score
0
City, State
sellersburg, IN
Year, Model & Trim Level
2002 xlt
Ok, have a couple of questions since I'm facing this problem right now. The engine is out, but we can not get the balancer to break loose. The puller is breaking bolts trying to get it to break free. With this being headache number one. The second is that when it was parked, the tensioner for the oil pump chain is gone also. When the vehicle was last driven, it dropped oil pressure just for a split second, and was trailered from there. Does anybody have any idea why the balancer will not break loose, and any other way to get it loose. And since it dropped oil pressure, even though there was no notable engine breaking sounds, is it even worth trying to repair the engine?

Thanks for any help.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




2000StreetRod

Staff member
Moderator
Elite Explorer
Joined
May 26, 2009
Messages
10,595
Reaction score
254
City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
balancer puller

. . . The engine is out, but we can not get the balancer to break loose. The puller is breaking bolts trying to get it to break free. With this being headache number one.

You're probably using a standard balancer puller with the diameter of the center bolt exceeding the diameter of the crankshaft. The result is the puller is trying to pull apart the balancer instead of trying to separate it from the crankshaft. Read post 3 of this thread.

The second is that when it was parked, the tensioner for the oil pump chain is gone also. When the vehicle was last driven, it dropped oil pressure just for a split second, and was trailered from there. . . And since it dropped oil pressure, even though there was no notable engine breaking sounds, is it even worth trying to repair the engine? . . .

I don't understand. The oil pump is driven by a shaft, not a chain.
OilPumpShaft.jpg

Dropping oil pressure for a few seconds should not have caused bearing damage. The engine runs that long without oil pressure every time it is started.
 




Top