4.6L Explorer engine timing chain ooops!

Got a local customer with an Explorer who came to the shop with a noise coming from the front cover. As I suspected the timing chain guide on the pass side was broken completely and both movable guides were worn through, right down to the tensioner. Attached is some pics.....

 

[rondhol]

Hi "Pontisteve".; I have that kind of noise. Like marbles in the can but only after the engine is hot (20 minutes driving). Only under certain load (light load) to keep constant speed 30-40mph at arround 1500 rpm. No noise in N or Park.

Do you have that noise when the engine is cold?

 

[Pontisteve]

I have no noise in N or Park either, only under forward acceleration. Engine temp doesn't seem to play a factor. At wide open throttle, the noise seems to be reduced or gone, but that might just be because the engine is in higher rpms or the sound drowns out the noise. My noise seems to go away entirely at rpms above 3000 or so, and also in 5th gear, or when the converter locks up. This lead me to believe it's load related. The noise is loudest when accelerating moderately (1/2 pedal), in 1, 2, and 3rd gears. My best guess is that I have worn timing chain guides, but I'm open to suggestions.

Your symptoms kind of sound more like a possible spark knock problem to me. If an EGR valve doesn't open up, spark knock can occur. And interestingly, EGR doesn't happen at idle, or when cold, or when at WOT. It happens mostly under light to medium acceleration, and when cruising. All symptoms you have. Then again, modern EFI engines measure EGR flow, and if the flow is not adequate, a check engine light will come on. The code will say insufficient EGR flow. If you think you could possibly have spark knock/detonation, checking the codes would be a good place to start. Especially if your check engine light is on.

A long time Ford tech I ran across was doing some front axle work on my truck once, and test drove it when he was done. He came back telling me that he has heard that noise often before, when he worked at Ford, and that it was timing chain issues. So far, my best guess is that he's right. But I'm trying to find out as much as possible, before ripping the front of the motor down for nothing.

 

[tjm183]

Help - timing chain rattle!

Hello
I have a '03 eddie bauer explorer 4.6L V8 SOHC and I have heard a new noise coming from the engine at 91K. I have 2 mechanics diagnose the noise and both agree it is probably the timing chain guides. The estimates I've received for the job are $1,800 to $2,200. I've been told to do this ASAP; the chain can slip and do more damage; permanent engine damage.

Has anyone else had this issue? Can I have a mechanic friend do the job? Are there special tools required? Looking for any feed back and responses please.

Thank you,

Tom

 

[99ExploratorySUV]

Can somebody please explain to me why they make these guides and tensioners out of **** @ss plastic? Seriously, who's brilliant idea was that? OH! YEAH I KNOW WHAT'S DURABLE! PLASTIC! This really makes me wonder. I mean its only in these new overhead cam engines that these plastic crap tensioners and guides are used, right? Seems like the 5.0 wasn't so bad after all. Maybe Ford realized they were too good at making engines that didn't take a **** till 400k. Hmm... we need people to stop driving their old cars and buy our new ones... I KNOW! PLASTIC TENSIONERS! YAYYYYYY. sorry for rant.. but seriously, doesn't anyone else feel this way? I feel betrayed.

 

[tjm183]

Hello 99exploratorysuv

you are exactly right! these engines are designed to fail! that is my problem right now, i think the plastic guides are worn down to the tensioners. i'm trying to gather as much info as possible before I go forward with fixing it with my friend whose a mechanic. do you have any advice?

thank you,
Tom

 

[99ExploratorySUV]

Hey tim, to be honest, I'm not too sure. It really depends on your financial situation and what you want to pay for. I know some people on the website have tried it themselves, but to be honest, that's definitely something I'd never be interested in trying, even though I attempt as many jobs on my car as possible. I've heard that the job is usually going to cost that much. I guess if you want to keep the car and keep driving it, get it fixed. It's just one of those situations, you know. I mean it's either that, or a new car, or an engine swap. Engine swaps could be expensive, but maybe not too much more so than what it'll cost to get your current one fixed.

 

[Pontisteve]

I've got the Ford repair CD, which I just looked over. I've also done the job on a 4V cobra motor before as well. Just roughly what's involved is to remove the radiator shroud/fan, all the accessories, the little PS pump, all the rocker arms (cam followers), the front timing cover and belt tensioner, and then the chains and guides. Then you put it all back together, and before you put the rocker arms back on, you set the cam timing using an OTC Ford Modular 2V cam timing kit (around $100). This makes sure you have the cams timed right with the crank. If you have the OTC kit, that takes the drama and expense out of it. Once the cams are timed, you release the clips that hold the timing chian tensioner compressed, and you're good to go. I have this on .pdf if anyone wants a copy.

This isn't a terribly hard job, but it would be time consuming. Having the ford cd ($25 on ebay), or the shop manual, or at least copies of it would make it a step-by-step job. The harder part is figuring out which tools you need, without buying the individual tools from Ford. The only really special tools I saw or can think of are: Modular 2V cam timing kit, PS pulley puller and installer (or PS pulley remover/installer kit), and the rocker arm removal tool (2V valve spring compressor - $100). If you want to be cheaper about this, here's some tips: You can use a flathead screwdriver to install/uninstall the rocker arms... there's a video of how to do it on one of the video sites, or I have it saved. Next, a PS pulley kit can be bought at Harbor Freight for like $10. It's not great, but it works. To install the PS hose teflon seals, you just use a cone shaped piece of metal to roll the teflon seal up on until it's stretched out enough to fit over the tube nut. Once stretched, you install it and wait for it to shrink before reinstalling the PS line. Valve cover gaskets might be able to be reused if in good shape. Timing cover gaskets MUST be replaced. Installing a new front main seal would be a good idea.

To answer the question why anyone would build this stuff out of plastic??...

On overhead cam engines, the timing chains become very long. They won't hold tension by themselves, so they need a tensioner setup to take up the slack. So one side of the chain has a guide that the chain just rolls across, while the other side of the chain has a tensioner that has to push on the chain somehow. So the tensioner pushes on an aluminum guide, covered in plastic. It's not like it's China plastic toy plastic were talking about here. Im sure it's very good nylon, like Delrin or something. Probably is Delrin actually. (Dupont spent $50 million developin Delrin in the 1950's). But with constant metal chains sliding across it, eventually the plastic wears. Especially if the engine isn't maintained well.

I believe that the noise in my motor is most likely the timing chain tensioner arm (aluminum) rubbing against the timing chain, because parts of the plastic are worn off. A change in engine load probably slacks the chain up some, and causes it to ride in a spot where more plastic is, or at least not push on the aluminum as much.

Ford probably felt the value of OHC's outweighed the increased maintenance needs of the fancier timing chain setup. The rest of the motor is nearly bulletproof for stock.

Oh, by the way, these modular motors can make up to 2300 HP using the stock block, heads, cranks, and timing chains. Google John Mehovitz or Steve Matusek. We ran a 5.4 4V Navigator engine to around 1400 rwhp using the stock iron block, stock heads, stock crank, stock timing chain components, and good rods and pistons and bolts. I have to disagree with the comment that these engines are meant to fail. They are not.

I'm betting the tools, parts, fluids, etc will probably run you around $350 - 450 if you hunt for a deal on them. Try usatoolwarehouse.com, tooltopia.com, and toolsource.com. Oh, and sears.com.

 

[99ExploratorySUV]

Pontisteve, thank you for that very in depth reply. I have the 4.0 SOHC V6, and I heard that this same problem could happen, so I was pretty upset upon hearing about it. Thanks for the explanation of how the repair goes... it actually doesn't sound too terrible if you can get all the proper tools. Hopefully mine won't break for at a while, but at least now I know there's some chance I could be able to do it myself. Cuz I really like my car and how its setup and don't wanna get rid of it. Do you consider these failures to be common? My family has had my ex since it was new in 99, and we've been **** about oil changes and maintenance. Since I've inherited it, I've switched to synthetic and haven't gone back since. Is this kind of failure preventable altogether, or will all OHC engines eventually succumb to it? By the way, what's the exact title of that ford repair CD so I may look it up as well? Thanks again

~Kyle

 

[Pontisteve]

I bought a Ford service manual for 2000-2004 Fords, on CD on Ebay for about $25. Looking at the label on my CD, I think they may have been a pirate copy, as the Ford cds look etched, not stickered. Anyway, it works great. I didn't see the same ad on Ebay now, but just type in "Ford service manual" and you'll find all sorts of ads. You can find paper or cd versions. I found what sounds like you need here:

http://cgi.ebay.com/ebaymotors/1999-FORD-TRUCK-ALL-SERVICE-MANUAL-ON-CD-F-SERIES-MORE_W0QQitemZ180346394715QQcmdZViewItemQQptZMotors_Manuals_Literature?hash=item180346394715&_trksid=p4506.c0.m245&_trkparms=72%3A1205%7C65%3A12%7C39%3A1%7C240%3A1318


The 4.6 V8 engine, while fundamentally the same OHC design, is a different animal than the 4.0 SOHC V6. I actually have that engine in my 98. I'm no expert on the 4.0's for sure, but I did look up a 2000 4.0 sohc engine on my repair cd (an oem manual). Scary. Let me TRY to describe this setup...

The crank has a chain that goes up to a jackshaft (which is about where a traditional camshaft would be). This chain has a guide and tensioner. From the jackshaft, there is a chain that goes up to the LH head's cam sprocket. This chain seems to be tensioned by what they call a cassette. I believe the cassette surrounds the sides of the chain. The tension is provided by a screw-in (oil pressure fed?) tensioner that appears to be at the front of the head, screwed in from the intake manifold side of the head.

Back to the jackshaft, it runs through the engine like a traditional camshaft would, and comes out the back side. The back side has a chain that goes from the jackshaft up to the rear of the passenger side heads OHC. It probably has a cassette too, and a screw in tensioner. The tensioner seems to screw into the head in the back, just below the valve cover, on the outer side of the engine.

On 4WD vehicles, there is another chain. It is a short chain that goes from the crank pulley towards the passenger side of the engine, where there is a balance shaft. That looks like some sort of bolt-on assembly, possibly external.

There are many special tools, and you apparently have to time both cams if you mess with either. Also, it appears to me that you CAN NOT loosen the crank bolt unless you have a special tool holding the crank pulley in place first. I've heard that before.

Wow, remind me never to buy one of these again. Very complex looking motor. If the timing chain tensioners are bad, they look like they pretty well just screw in. But if the tensioner arms/guides/cassettes go bad, it looks like major work. I have always heard that if the rear chain tensioner setup goes, you have to pull the motor to fix it, and I would say that appears to be true. If you have a front chain problem, you could probably fix it in vehicle, and then retime both cams (for which the motor does not need to come out). But the front cover doesn't look like any fun.

Back to the 4.6 for a minute, one of my concerns isn't so much that the truck will jump time or throw a chain. I think the tensioner and arm probably provide enough tension to keep the chains in check. But if the plastic wears off the tensioner arm, then you have bare chain on aluminum arm. This would lead me to believe that plastic and aluminum shavings have to get into the oil. Probably the oil filter takes care of this, but still... not very comforting.

 

[99ExploratorySUV]

Wow, that sounds pretty complex... haha a lot more intense than the 4.6 setup you described. Hmm, I don't know if that's something I'd want to dirty my hands with. But thank you for describing that for me. I know, these engines are pretty intense. Makes me wish I still had my old 1995 5.0 Mustang. So, what do you think the options are? Keep changing the oil as early as possible and hope for the best? Or a get a new car before I'm completely screwed with a 1500-2000 repair bill? Would you say that this kind of wear is inevitable on all of our engines, 4.6 and 4.0, or is it just a matter of keeping it clean and lubed?

 

[Pontisteve]

Well, I suppose if it were me, I would think about stepping up to a newer truck. The repair costs may be too high in relation to the value of the car. If you trade it off, chances are the dealer taking it in wouldn't know the difference... especially new car stores.

Unless you're a pretty patient person with lots of time on your hands, and really good with wrenches, I would say this job isn't worth doing. But it really depends on exactly which part is determined to be bad. Diagnosing this particular 4.0 engine could be tough. You may want to scour the forums and see what part is normally at fault, and if it's a hard one to fix. The tensioners that screw in externally sound easy to fix. The guides themselves don't. Especially the rear one.

Another option is to drive it into the ground, and just buy a used motor when she dies. I have heard stories on the internet about guys doing just that, and the motors go a lot longer with noise than you would think. I doubt changing the oil more often would really help much, because the filter does a very good job. Definitely don't use a cheap filter though. Motorcraft should be fine.

The OTC cam timing set for 4.0 SOHC is a OTC 6488. I found it at usatoolwarehouse.com for $160. Those guys always have some of the lowest prices around, and good service too. I've used them a bunch.

I would also say that if this is your first timing chain job on an OHC engine, well... I wouldn't want this motor to be my first try.

Yes, on OHC engines, this type of wear is probably typical. The problem is the chains are long. They go from the crank all the way to the top of the cylinder heads. With chains that long, you have to tension them. And some sort of plastic guides is about the only way to do it. An alternative way to get rid of the guide situation permanently would be to have just used a timing belt instead. But they have to be changed periodically. And I can just hear the comments from the crowd about how stupid Ford is, because they put timing belts on V6 & V8 engines. It wouldn't go over well.

Ironically, for really high powered small block V8 traditional engines, the absolute best racing cam timing setup you can get is a Jesel BELT drive.

 

[99ExploratorySUV]

I really appreciate your input, you definitely are well informed on this subject. It can be a tough call with these kinds of things, cuz you never know when stuff like this can fail. I'm definitely kinda disappointed that most of these OHC engines suffer from this. I feel like a truck should be able to hit 300,000 miles with no major problems, (tranny excluded), but I guess if every truck was like that, Ford wouldn't have as many new buyers. But you're probably right about stepping up to a new truck. Hopefully mine will hold out till I can scrounge up some cash or even get a loan for something relatively newer. Have you heard anything good about the longevity of those I4's in the rangers? Or at least the 3.0L sixes that some of them have? If I get something different I definitely want it to be able to keep on chugging for a while. Tranny is one thing, not much you can do about that except keep fresh fluid in it, but engines should last much longer than 200,000 miles without crap like this breaking in my opinion. It's just not acceptable lol.

 

[Pontisteve]

I'm not a big 4 cyl truck fan, or a Ranger fan either really. But the 4 banger has come a long way since the clunkers of the 80's. They're not bad, just gutless. They are more dependable than they used to be. The 3.0 and 4.0 V6 seem to be pretty good motors. Never had much trouble with them. Pretty simple trucks, with traditional designs.

The newer Explorers (02-up) are much nicer than the pre-02's were. They ride much nicer, get better gas mileage, are bigger and more comfortable, and have more power. Even the 6 cyl is much peppier than the older ones ever were. I like mine. But they're known for front and rear hub assemblies (no more serviceable wheel bearings) going bad. They may have tranny issues as well. The 4.6 motors are good though. The newer ones even get the 3v 300hp 4.6.

The 2V 4.6 in the mustang (basically the same engine as in the explorers) seem to go for a very long time, even under abusive owners. So I think the 4.6 motor itself is not inadequate. Perhaps the heavier truck puts more drag on the timing components?

 

[tjm183]

Hello Steve & Kyle,

I'm extremely grateful for all the feedback and advice! I’m using the barter system; my friend will work on my truck and I will wire his house and give him a rebuilt computer. I am trying to gain as much knowledge as possible to help my friend. You guys have been helpful beyond my expectations!

Steve, is there anyway I can get a copy of the pdf you were talking about in your 4/13 post. I’m going to purchase the timing chain kit after my friend confirms that’s exactly what it is; I have a motorcycle to ride in the mean time. Right, there is no diagnostic test to do to confirm it’s the timing chain until you take it apart?

When I purchase the timing chain kit do I need to know whether my engine is a ROMEO or WINDSOR? I think my engine was produced in Romeo, Michigan, because there is a “W” in the eighth position in the VIN; which I would have thought meant W for Windsor, Ontario.

While my friend is working on my truck, which will probably be a two week side job, is there anything else I can do to increase the performance or engine life?

Sorry I couldn’t respond sooner. You guys have been great thank you!!

Sincerely,

Tom

 

[Pontisteve]

Tom,

Not sure which 4.6 plant the explorer motor was made in, but I doubt you need to know that when ordering the parts. But I'm sure you can find that answer at corral.net/forums. There's always talk on there about where engines are made, and what their differences are.

You can send me your email address thru a PM, and I'll try to send pdf's to you. I think I can make that happen. I'll need to know your year and engine.

You can try to use a stethoscope against the left and right side of the front timing cover, to see if you can hear anything. You may have to have someone vary engine rpm while you listen. That alone might not get it though, because you may have to vary load as well, which would make it impossible to use the steth unless you own a chassis dyno. The noise has to be coming from somewhere, so try to pinpoint it before heading into a cam timing job. Other possibilities are belt-driven accessory noises (check them all first), catalytic converter rattle (check by smacking them with a rubber mallet), cat converter heat shield rattles, etc.

I wouldn't order the parts until you dig into the motor. Generally speaking, you'll find that it needs either a tensioner, tensioner arm, or guide. Probably not chains. I would recommend Ford parts, but Cloyes also makes them.

In racing, we've come to know that the guides and tensioners should be replaced once in a while. They sometimes just break, sounding like a motor knock. We think it's harmonics related. In stock vehicles, I think the same policy should probably apply, just due to the plastic wearing on the tensioner arms. Your best bet is to pull it apart, and replace anything suspect. You don't have to worry so much about chain stretch (unless the motor is really hi miles), since the chains are tensioned, and the cams are timed anyway. Although in racing, we take it about a hundred levels deeper, by degreeing in the cams. (What a mother that is on a 4V!)

There's tons of stuff you could do to increase performance, with nothing limiting you but your wallet. But assuming you're talking low dollar stuff, the basics are almost always a K&N air filter, rear end gears, exhaust upgrades, eliminating the cats, and a computer tune. A larger throttle body, a different intake, and a cold air inlet pipe are also popular.

Without spending any money, here's a couple maintenance tricks you may find helps your truck run smoother. I use these all the time...

1) Clean your Mass Airflow Sensor. Use MAF cleaner or Brakleen, and be super careful not to break the little wire or resistor. The MAF gets a carbon film on it with age, and can change the computer tune slightly, causing rougher running, or more commonly, a reduction in gas mileage.

2) Clean your air filter and box. All kinds of nasty stuff ends up in the box.

3) Clean the EGR valve, and make sure it functions properly by testing it with a vacuum gun. This often times fixes stumbles at idle.

4) Clean the Idle air control valve. While usually not necessary, sometimes this can make the car idle better. Reasons for cleaning it might be a fluctuating idle, or a low idle.

5) Take the coil packs out, carefully pull the plug boots out, and carefully pull the spring off. Clean the contact where the spring screws onto the coil. These are often corroded, and not seen unless taken apart. Clean everything thoroughly, and reassemble, using dielectric grease on the spring end that goes on the spark plug. While you're at it, take shop air and blast the spark plug wells out. They get junk in them. And since you've gone that far, a new set of plugs is easy to install.

6) If you have an obd2 scanner, you can look for problems in the pcm, particularly O2 sensor sweeps. O2s wear out about every 100K. Long Term Fuel Trims that are somewhat large (over 4-5%) could be a telltale sign that the O2s are wearing out. Long, slow sweeps also show aging.

As for engine life, just run Motorcraft 5w20 oil and the FL-820S filter. No cheapies. The hydraulic lash adjusters and cam timing tensioners are designed to work with this weight oil (5w30 probably fine too), so don't go switching up to thick oils.

You could also service the rear end if you have around 100k on the truck. Ford has a TSB that states you should switch up to 75w140 synthetic gear lube. I think that's a good idea. If you have a posi, don't forget the posi additive.

 

[insane3082]

wow i think this is what im about to find inside my 4.0 i really wanna fix it cus my engine is good on gas and it runs strong. i love my X i dont wanna have to divorce my baby.

 

[customford03]

4.6 not sure whats wrong

I just picked up a 97 cobra mustang with the 4.6 dohc has 92,000 and it seems like the car has ben aboused. I had some people listen to the engin and they said it sounded like a lifter knock I took the valve cover off its on the passanger side could the only thing I found wrong with it was the secondary timing chain is a little loose the rivits on the side closes to the ratatior on the chain looks like they have ben rubing on something so I got a new chain have not put it on yet. Then some one told me it is probly the guids the main or longer chain on that side is tight does not move at all. I dont have the timing chain cover off and honestly dont feal like taking the engin that far apart but I dont feal like haveing a vave hit the piston. What do you sugjust is it worth taking the cover off and checking the guids. Like I said it sounded like a lifter knock on the passanger side. Thanks

Got a local customer with an Explorer who came to the shop with a noise coming from the front cover. As I suspected the timing chain guide on the pass side was broken completely and both movable guides were worn through, right down to the tensioner. Attached is some pics.....

 

[Pontisteve]

The short chains on top are not normally problematic. Much more likely is the guides or tensioners. If a guide fails bigtime, it can sound a lot like a lower end knock. Very pronounced. You might be able to sneek a boroscope down into the timing cover from the top valve cover area, and have a look around inside there. Take a hard look at the plastic on the guides.

 

[customford03]

4.6 DOHC timing chain job?

Hi again 97 4.6l DOHC cobra mustang replaceing timing chains and guids.

I checked out the guids on the passanger side secondairy chain and shockingly they are bairly worn at all but i looked at guid on the primary chain on that side and there was no guid there well the metal part is there but no teflon so the chain is riding on metal so I picked up all new gears chains tensioner and guids and a felpro front cover gaskit. I dont have much more to do before i can take the cover off but my real question is on all data and in the ford shop manuel show that i need a tool witch looks not much more than a plate that goes over the 2 cams to hold them in place while you take gears and chain off so the timing does not change , also a secondary timing chain tensioning tool, and a camshaft positioning tool. The first 2 tools make sence for the job but the 3rd tool does not realy make sence because you can not even use it till you take the gears off is that tool usefull in any sence . And where can you get these tools or even rent them I can not find them any where? and is there any advise or anything I could get for doing this job I have never worked on a DOHC motor before I dont not want to mess this job up any help or advise would be great thank you

 

[Pontisteve]

You need the OTC 4V cam timing tool kit. It has all of the factory tools in one kit that you'll need. (OTC makes Rotunda tools, which are the factory Ford tools). Price varies, but here's a couple very good websites to check: Sears, tooltopia, usatoolwarehouse, ebay. As I recall, I think I got mine from usatoolwarehouse, but I think Sears might have been cheaper (to much surprise). Usatoolwarehouse sells them on Ebay as well. I love them guys... so cheap for great tools!

There should be a tool for holding the 2 cams together, to keep them from moving. Then, there's a tool for holding the crank in the right position. Then, on the back side of the camshafts, there are some D shaped slots, that a tool fits into, that lines that cam up. As I recall, it lines both cams up at the same time. Before you disassemble the motor, you probably should turn the motor over to TDC on cyl #1 (passenger front cylinder). This way you don't have to time everything from scratch. By the way, be careful not to use any tool with much force in the back of those cams. Those D shaped slots can turn inside the cam apparently, so use them for alignment, not for cam rotation.

In a job like this, if you are just replacing the tensioners or guides, you could probably just lock the cams using any DOHC cam locking tool that prevents the cams from turning, pop off the tensioner, change the parts, put the tensioner back on, and retension it. But using the factory cam timing tools will keep you from making any costly mistakes, plus allow you to set timing from scratch, not just hold the cams.

A couple things you might need to know: crank bolt and cam gear bolts are torque-to-yield. You cannot reuse them; ARP makes reusable and stronger replacement bolts; timing cover gaskets are never reusable; other gaskets generally are reusable; factory cam timing settings and actually degreeing in the cams are 2 way different things; it's a total mother to degree in 4 cams; I've done it; you can't bend valves if you take off the factory cam followers; there are 2 different valve spring compressors required on a 4V to take off the cam followers the factory way; they're over $100 each; you can accomplish the same thing with a screwdriver if you have to; doing this job right, you shouldn't really need to take the cam followers off if the cam timing does not move.

Here's a few pics of my 97 Cobra timing chain setup:

Both cam timing tools. I think the 4V tool is OTC 303-452. The 2V tool is much more common to find on the internet, and it works on the exhaust springs of the 4V, but you need the 4V tool to compress the springs on the intake side on 4V motors. The internet is really unclear at first, when you try to find these part numbers for these tools, which is why I find it important to pass that on. Again, you can probably avoid having to take off the cam followers entirely if you get the motor set up at TDC on the intake stroke before pulling the timing components off!

Back of 4V cam (lineup indentions). RI-SN stands for Right Intake - SN95. (SN95 is Ford code for Mustangs)

Front of 97 4V motor...

4V timing tensioner. Note the ratcheting tensioner that ratchets out as the chain stretches. Also note the hole in the tensioner. Once you compress the tensioner, and recompress the little plastic ratchet tensioner ladder, you put an allen wrench in the hole to hold it all together. When you reassemble, the last thing you will do is pull out the allen wrench, springing tension onto the chain.

You'll also need a power steering remover/installer to get off the PS pump pulley on mod motors. You'll need a good torque wrench for reinstalling the crank pulley. Be SURE to reinstall the crank trigger wheel before putting the timing cover back on. Notice how everything comes apart as you're disassembling. TAKE NOTES! Which was did the crank gear go? Which way was the trigger wheel facing? Etc.