Pontisteve
Well-Known Member
- Joined
- August 30, 2008
- Messages
- 519
- Reaction score
- 22
- City, State
- Florida
- Year, Model & Trim Level
- 03 Eddie Bauer 4WD V8
I own the 4v cam timing tool kit, and have done this job before. Here's a little boots on the ground info for you.
The chains rarely ever go bad. The guides and tensioners do. On the 4v, we replace the newer style phenolic tensioners with the older style cast iron ones, with the ratcheting ladder. They fail MUCH less. I think Cloyes carries those cast iron tensioners. I'm not 100% sure if they're the same for 2v engines like the Explorer, but if they are the same, try to acquire the cast iron tensioners.
The chains rarely go bad. Unless they have been loose and hitting the timing cover, I wouldn't sweat re-using the chains. However, they could stretch over many miles. I'm not against replacing them. Ford uses Morse chains, which are very good.
The tensioner arm and guide are what often break or wear out. These should be replaced every time you're in there, along with the tensioners. These six pieces are the weak links.
Personally, I think there is a connection between using regular oil and the guides/tensioner arms failing (by wearing out the nylon). Motorcraft oil in the lighter weights is semi-synthetic. If you look at the ratings on the oil versus other brands, you'll discover that Motorcraft oil is rated the same as full synthetic, where all other brands of non-synthetic oil are not rated as high.
In short, Motorcraft makes killer oil, and air/fuel/oil filters. Their stuff is very good. I use the Motorcraft 5w20 in my 4.6L explorer, and it has 156k with no signs of trouble yet. I believe that most people use whatever brand of 5w20 they like, other than Motorcraft, and I think that causes the nylon guides to wear prematurely. As these things wear, they can cause the tensioners to be ground down by the chains too.
The 2v valve spring compressor tool is the same one used on the exhaust valve of the 4v engines. The 4v intake valve compressor is unique. Explorers had 2v engines, but Aviators and Cobras had 4v engines. If you're doing this job just one time, I would watch the above referenced video on youtube, and learn how to use a flathead screwdriver to pop off the rocker arms. I've done it before, and it actually worked great on a 4v engine. With a little care, you can take all the rockers off.
You don't have to worry about rotating the engine and bending valves if all the rocker arms are off, because all the valves are closed. If you don't want to buy the OTC 2v cam timing tool kit (around $100), then do yourself a favor and set the engine at TDC on the compression stroke before tearing it down at all. In this scenario, you could just remove the chains and put the new parts on without needing the tool kit to re-align the cams.
The 2v cam holding tool is a bridge that goes from one side of the head to the other, and holds the cam in the middle. This keeps the cam from turning due to valve spring pressure. Guys have done this before with vice grips too. Just gotta get the vice grips to be touching the head so the cam doesn't move.
Since you can buy the cam timing tool kit for around $100, you could just buy it, use it, and then sell it to the next guy on here who needs to do the job for a bit less than you paid.
The crank holding tool basically just lines the crank up to something like 11:00 position. This is a safe spot that puts all the pistons down in the hole a little bit, preventing any possible piston to valve contact. You could duplicate this crank position by looking at pictures.
The cam holding tool is about the only important one, as it holds the cam from moving under valve spring pressure. But if you remove all the rocker arms, there is no pressure.
Personally, I don't think the cam gears need replacing very often. Not unless its really high mileage or something. They are hardened for a few thousands of an inch into the surface. Below that, they are soft. Unless you have somehow physically damaged one, they are generally pretty reusable.
Make sure the guide pins are in good shape. That one or two pins that the guides pivot on can break off or fall out or something, and take a motor out. I've seen them fail, but only in racing.
The chains rarely ever go bad. The guides and tensioners do. On the 4v, we replace the newer style phenolic tensioners with the older style cast iron ones, with the ratcheting ladder. They fail MUCH less. I think Cloyes carries those cast iron tensioners. I'm not 100% sure if they're the same for 2v engines like the Explorer, but if they are the same, try to acquire the cast iron tensioners.
The chains rarely go bad. Unless they have been loose and hitting the timing cover, I wouldn't sweat re-using the chains. However, they could stretch over many miles. I'm not against replacing them. Ford uses Morse chains, which are very good.
The tensioner arm and guide are what often break or wear out. These should be replaced every time you're in there, along with the tensioners. These six pieces are the weak links.
Personally, I think there is a connection between using regular oil and the guides/tensioner arms failing (by wearing out the nylon). Motorcraft oil in the lighter weights is semi-synthetic. If you look at the ratings on the oil versus other brands, you'll discover that Motorcraft oil is rated the same as full synthetic, where all other brands of non-synthetic oil are not rated as high.
In short, Motorcraft makes killer oil, and air/fuel/oil filters. Their stuff is very good. I use the Motorcraft 5w20 in my 4.6L explorer, and it has 156k with no signs of trouble yet. I believe that most people use whatever brand of 5w20 they like, other than Motorcraft, and I think that causes the nylon guides to wear prematurely. As these things wear, they can cause the tensioners to be ground down by the chains too.
The 2v valve spring compressor tool is the same one used on the exhaust valve of the 4v engines. The 4v intake valve compressor is unique. Explorers had 2v engines, but Aviators and Cobras had 4v engines. If you're doing this job just one time, I would watch the above referenced video on youtube, and learn how to use a flathead screwdriver to pop off the rocker arms. I've done it before, and it actually worked great on a 4v engine. With a little care, you can take all the rockers off.
You don't have to worry about rotating the engine and bending valves if all the rocker arms are off, because all the valves are closed. If you don't want to buy the OTC 2v cam timing tool kit (around $100), then do yourself a favor and set the engine at TDC on the compression stroke before tearing it down at all. In this scenario, you could just remove the chains and put the new parts on without needing the tool kit to re-align the cams.
The 2v cam holding tool is a bridge that goes from one side of the head to the other, and holds the cam in the middle. This keeps the cam from turning due to valve spring pressure. Guys have done this before with vice grips too. Just gotta get the vice grips to be touching the head so the cam doesn't move.
Since you can buy the cam timing tool kit for around $100, you could just buy it, use it, and then sell it to the next guy on here who needs to do the job for a bit less than you paid.
The crank holding tool basically just lines the crank up to something like 11:00 position. This is a safe spot that puts all the pistons down in the hole a little bit, preventing any possible piston to valve contact. You could duplicate this crank position by looking at pictures.
The cam holding tool is about the only important one, as it holds the cam from moving under valve spring pressure. But if you remove all the rocker arms, there is no pressure.
Personally, I don't think the cam gears need replacing very often. Not unless its really high mileage or something. They are hardened for a few thousands of an inch into the surface. Below that, they are soft. Unless you have somehow physically damaged one, they are generally pretty reusable.
Make sure the guide pins are in good shape. That one or two pins that the guides pivot on can break off or fall out or something, and take a motor out. I've seen them fail, but only in racing.