How to: Rear Timing Chain Tensioner Replacement

[junan]

I just wanted to say thanks so much for all the detailed info..We bought a 98 explorer and knew it needed something to do with the rear timing chain. The guy said it had started making a rattling noise and parked it. So we bought it for 500.00.. And thanks to all the info on here I believe we are gonna be able to fix it alot cheaper than the guy who sold it thought..We'll see though.

 

[2000StreetRod]

Visual inspection

Removing the valve cover(s) and performing a visual inspection is the only way to determine the actual state of the timing chain guide assemblies. If the rear guide assembly is broken (like mine was) eventually the timing chain will slip and valve damage is likely to occur. I was lucky to pull my engine before the timing chain slipped. See my lengthly thread SOHC V6 Timing Chain Saga

 

[rileyrs]

just curious where you got the 49 ft lbs number for the tensioner? when i checked alldata it said 30 ft lbs, and i just wanna make sure i torque it right when i do my tensioner soon.

 

[Vargas]

The torque spec changed at some point. I think it may be due to the possible addition of a sealing washer. With no washer, I needed to torque the rear tensioner on my Explorer to 60ft/lbs before it would stop leaking. My first efforts were 49 and then 54 ft/lbs. With a steel washer (like the one supplied in the 00M12 kit) it might take less, and with the copper crush washer available from the deal, perhaps even less.

 

[2000StreetRod]

Compression ring torque

just curious where you got the 49 ft lbs number for the tensioner? when i checked alldata it said 30 ft lbs, and i just wanna make sure i torque it right when i do my tensioner soon.

The Ford instructions for installing the primary timing chain kit:

". . . install the right hand camshaft timing chain tensioner.

If installing the original washer, tighten to 67 Nm (49 lb-ft)

If installing a new washer, tighten to 44 Nm (32 lb-ft). . ."

The Ford 2005 SOHC V6 assembly manual does not mention the old vs new washer and specifies 32 lb-ft.

The Haynes repair manual specifies 49 ft-lb.

Most of the replacement tensioners are being shipped without a new compression ring. I'll update my procedure for the old vs new washer distinction.

 

[rileyrs]

thank you very much for the info.

 

[XLTmodifire]

Great information indeed!

I do have the ticking sound coming from the top/rear at idle. I was thinking it may be one of the guides wearing/broken (which may still be the case). But I had no idea that just the tensioner alone could be the result of the ticking sound. What a refreshing feeling that I may be able to rid of this sound by myself.

Thank you for the great write-up. I will need to purchase a torque wrench, but I believe I should have one in my tool box by now anyway.

 

[steadyhand]

Since you have to remove the upper intake manifold to replace the left hydraulic tensioner, it won't cost you anything but time to remove the left valve cover and inspect the guide assembly.

Below is the link to the thread that describes replacing the primary tensioner and guide as well as the left guide assembly without retiming the camshafts. I emphasize that this is a risky process and I recommend at least checking the timing once complete before cranking or running the engine.

Timing Chain Pictures!?!

If your 1997 SOHC still has the original timing components then there is a good chance that the left guide assembly and the primary tensioner are broken.

Should the engine be making this rattling sound all the time? Because mine only does it at certain times, like when the engine starts running rough from idling too long. Otherwise it doesn't make the noise and seems to idle fine.

 

[steadyhand]

Besides the OTC 6488 tool kit that is needed for the timing, what other special tools do I need to get this job done right? I read somewhere else that there was a few other special tools that were needed. Anyone got a list of these tools?

Also, the prices must have really gone up on the parts. The cheapest upper left tensioner I've found is $70. The back one is $36. Napa says they got a kit which has the tensioner, chain, cassette, etc. for $144.

 

[2000StreetRod]

Otc 6488

I would not purchase the OTC 6488 tool set ($180) until I was sure that the left guide assembly is broken unless you have to minimize the time your vehicle is not running.

 

[steadyhand]

I would not purchase the OTC 6488 tool set ($180) until I was sure that the left guide assembly is broken unless you have to minimize the time your vehicle is not running.

How does this look to you? Is this the right spot and does it look broke? I didn't see anything broke so I assumed it wasn't. The driver side of the chain is loose, the slack side I'm assuming. The passenger side or right side of the chain where the guide is at seemed tight. I couldn't move it but I could the slack side just a little. How does it look to you and do you think a tensioner only is the place to start?

 

[steadyhand]

Couple other pictures. They are a bit blurry. My camera is rather old and there wasn't much light under the hood. Also, I did not see any sludge under the valve cover, just normal oil staining and a little crud or oil build up, but no sludge or milky substance.

 

[steadyhand]

Couple other pictures. They are a bit blurry. My camera is rather old and there wasn't much light under the hood. Also, I did not see any sludge under the valve cover, just normal oil staining and a little crud or oil build up, but no sludge or milky substance.


EDIT: Actually, after looking at another photo someone else put up, isnt there suppose to be a guide on the other side of that chain? In another photo I saw of a new guide put on, it looked like the guide was on both sides of the chain. On mine, as you can see in the photo, you only see the guide on one side of the chain. What am I looking at here?

 

[steadyhand]

IF I only have to replace the cam cassette, will the specialty tool lock the jackshaft and cam together just so I can slide the chain off the cam in order to tighten down the cassette? Will the engine still need to be at TDC for this since it isn't getting moved and the jackshaft and cam are locked?

Is it possible to replace the primary chain tensioner and not have to remove the chain?

I hate the idea of tearing this down and not replacing the primary tensioner as well as the left cassette/guide. At the same time, I hate to have to buy more specialty tools aside from the 6488 kit.

Either way, given my luck I'll bet I replace both the primary guides/tensioners and the left side and a short time later my rear chain will fail.

 

[2000StreetRod]

traction side missing

The inner side of the chain with the hydraulic tensioner is actually the slack side of the chain. The outer side is the traction side. The only decent photo is the first one of the slack side and the upper section of the guide assembly appears to be intact. I can't tell much from the other photos but it appears that the entire upper section of the traction side is missing and the chain is sagging. Your comment that the driver side of the chain is loose supports that. You must have the original style left guide assembly with no metal reinforcement.

If you remove the front timing cover you will probably find pieces of your guide assembly at the front. If you remove your oil pan you will find more. And if you look in your oil pickup tube screen there will be pieces lodged around the inner side.

In my opinion your left timing chain could slip at any time because of the chain slack and your exhaust valves on the left bank could strike the pistons. If that should happen then the head would have to be pulled, valves replaced (special tool required), head gasket and head bolts replaced in addition to the timing chain components. However, you might be lucky and drive for another 10,000 miles with no slip. The plastic pieces that are loose in the engine could move and block the oil pickup reducing your oil pressure.

I suggest that you remove the front timing cover and inspect the primary tensioner. It usually fails before the left timing chain guide assembly.

 

[2000StreetRod]

timing chain questions

IF I only have to replace the cam cassette, will the specialty tool lock the jackshaft and cam together just so I can slide the chain off the cam in order to tighten down the cassette?

A cassette consists of the timing chain, guide assembly and sprockets. You can't replace the left chain without removing the jackshaft sprocket. When the jackshaft sprocket retaining bolt is loosened both camshafts must be retimed. It may be possible to replace the left guide assembly without removing the chain from under the jackshaft sprocket. The Timing Chain Pictures thread I provided a link to in an earlier post describes how one member did it.

The following post describes how the timing tools are used:

SOHC V6 Camshaft Timing

Will the engine still need to be at TDC for this since it isn't getting moved and the jackshaft and cam are locked?

It is best to have the #1 piston at TDC on the compression stroke before removing the front timing cover or loosening either camshaft sprocket.

Is it possible to replace the primary chain tensioner and not have to remove the chain? . . .

Yes. Many members have replaced the primary chain tensioner and guide without removing the primary chain.

 

[steadyhand]

I'm confused about something so bare with me. I think I am misunderstanding you on something. You said if I loosen the jackshaft bolt, both cams will have to be retimed. What then is the OTC tool kit used for? I was under the impression it was suppose to lock the cam and jackshaft together. Wouldn't that keep the timing from getting thrown off so a person could just remove the chain, replace the guides, and put the chain back on? I think I missed something. I've been reading so many posts on this subject so it's all one big ball of confusion now

I don't have a choice but to do this myself. I really don't want to pull the engine out so if the timing is thrown off for the right timing chain, does the engine have to be out to retime that cam? I read a post, maybe yours, on the timing and making sure the cam position sensors were parrallel to the head surface. This leads me to believe a person is manually retiming the motor and the tool kit didn't lock anything in place.

My situation is, as far as I can tell at the moment, I will be replacing the left cassette and primary tensioner/guide and maybe the chain if it isn't too big of a headache.

 

[steadyhand]

Ok, I've been staring at the pictures and tools as well as reading even more posts and I think I have a better understanding on this. Please correct me if I'm wrong on any of this.

The engine does not need to be pulled to retime the right cam? I saw a tool that conects to the rear (front of engine) of the right cam, thus locking it into place.

In a nutshell, the procedure is...

Put crankshaft at TDC for cylinder #1

Install cam locking tools

install chain as a method of stopping the jackshaft from turning

remove jackshaft bolt

remove sprockets and left cassette(chain, guide, tensioner, etc)

replace with new parts

???Not sure I understand making sure it is tight on the traction side. I suppose I'll figure this out when I am actually looking at it up close again???

unlock the cams so they can be turned and the cam position sensor set above centerline and parallel to the head surface (basically straight out at what ever angle the head is at)

Lock cams while in the correct timed position

swap chain to other side of engine to tighten down the jackshaft bolt

replace primary chain, tensioner, guide, etc.

remove cam locking tools and timing "should" be set.

(I'll be cleaning out the oil pan and all soon. I haven't looked at it yet, but I feel safe in betting it needs done. I'm sure the oil pick up looks bad.)
................


Ok what did I miss or get wrong?

I know that sounds so much easier than it actually will be and I dread doing it but I know I couldn't possibly mess it up any worse than some of the mechanics around here.

Come tax season I might pull the engine and do the back chain, but for now I need to get the front chains done and get this back on the road. I drive to work 30 miles away every day. As I said before, the engine was running fine so I know I haven't done any damage, yet. It isn't being ran now and it will not be until this job is done.

Btw, what do you think of this parts kit? Even though I won't be using the parts for the rear, this is still the best deal I have found to get all the parts that I will be replacing in one package.

Also, I can't find a new jackshaft sprocket bolt or crankshaft damper bolt. Must be dealer only.

 

[2000StreetRod]

timing chain parts source

The only timing chain parts I would consider buying for my vehicle are Ford and Cloyes. I have heard and seen photos of some aftermarket guide assemblies that were warped and/or flimsy. A Cloyes engineer told me that the guide assemblies in their kits are made by the same company that makes them for Ford. There may be other quality kits available but I don't which ones they are.

I purchased my timing components online from a Ford dealer: www.tousleyfordparts.com

 

[2000StreetRod]

a few comments

Ok, I've been staring at the pictures and tools as well as reading even more posts and I think I have a better understanding on this. Please correct me if I'm wrong on any of this.

The engine does not need to be pulled to retime the right cam? I saw a tool that conects to the rear (front of engine) of the right cam, thus locking it into place.

Correct. The engine only needs to be pulled to replace the right camshaft chain or guide assembly.

I started edited your process but ran into a problem. The balancer retaining bolt takes a greater torque (44 ft-lbs+90 deg) than the front jackshaft retaining bolt (34 ft-lbs +75deg) or the camshaft sprocket retaining bolts (62 ft-lbs). That is why the Ford procedure calls for installing the front timing cover and balancer retaining bolt before timing the camshafts. With my engine out of the vehicle I used a chain bolted between the flexplate and the rear of the engine to prevent the crankshaft from rotating when I torqued (>100 ft-lbs) the balancer bolt. With your engine in the vehicle you'll need either a strap wrench around the smaller diameter of the balancer or something like a pipe wrench with deep jaws.

Also, pulling the balancer is a multi-step process because it is so deep. You will need special metric bolts that don't come with the puller kit.

Here's what I have so far, but it's not done yet. I'll work on it more late this evening.

Put crankshaft at TDC for cylinder #1 On compression stroke - not exhaust stroke

Install crankshaft balancer strap wrench or pipe wrench

Loosen crankshaft balancer retaining bolt

remove strap wrench

install balancer puller

tap with hammer and screw puller bolt until balancer contacts bolt

remove puller, loosen balancer bolt more, install puller, then tap and screw

remove puller, loosen balancer bolt more, install puller, then tap and screw

remove puller, remove balancer bolt, install smaller but longer bolt, install puller, then tap and screw

remove puller with balancer

remove timing cover being careful not to damage crankshaft seal

install chain and bolts (improvised tool) as a method of stopping the jackshaft sprocket from turning

remove jackshaft sprocket retaining bolt

remove chain and bolts (improvised tool) from jackshaft sprocket

remove crankshaft and jackshaft sprockets with primary chain (do not remove chain from sprockets), left hydraulic tensioner and left cassette (chain, guide, sprockets)

Install left cassette, front primary tensioner and guide

Install crankshaft and jackshaft sprockets with primary chain (the crankshaft sprock has a front and a back)

Install new jackshaft sprocket retaining bolt

swap chain (improvised tool) to other side of engine to tighten down the jackshaft bolt

torque new jackshaft bolt to specification

install front timing cover

install crankshaft balancer

install crankshaft balancer bolt

install balancer strap wrench or pipe wrench

torque balancer bolt to specification

Put crankshaft at TDC for cylinder #1 On compression stroke - not exhaust stroke

Check right camshaft timing, if not correct loosen camshaft sprocket retaining bolt, install crankshaft locking tool, install cam locking tools on right camshaft, replace right hydraulic tensioner with tensioner tool, tighten sprocket bolt, replace tensioner tool with right hydraulic tensioner, remove timing tools from camshaft

replace left hydraulic tensioner with tensioner tool

install timing tools on left camshaft.

tighten left camshaft sprocket retaining bolt to specification

replace tensioner tool with left hydraulic tensioner

remove timing tools from camshaft