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Toyotas

Toyota Timing Belt Replacement: V6 Engine Applications

Edited from an article by Larry Bailly, ImportCar Magazine

Toyota models started appearing on the West Coast at a time when there were still Mom and Pop stores in every neighborhood and there were one-screen movie theaters in every town. At first, the Toyotas were a pretty good miniature version of popular American cars. It became obvious from the beginning that quality, economy and durability were built into each car. The only thing that has changed in the last 40-plus years is that the Toyotas that are sold today are the standard against which we compare other brands. When properly maintained, many high-mileage Toyotas rack up more than 300,000 miles, without having had major engine or drivetrain repairs. But, like all other cars, they still do need routine maintenance. Indeed, the only common denominator in a seldom-seen engine failure on a Toyota is a lack of maintenance.

Since the late 1980s, Toyota has equipped its flagship models, the Camry series and its small trucks, with two series of V6 engines. The Camry line, including the Sienna Van, uses the 2.5L 2VZ-FE, 3.0L 3VZ-FE or lMZ-FE series engine. The trucks, up to the new Tundra, carry the 3.0L 3VZ-FE or the 3.4L 5VZ-FE series as either its base or optional engine. Both of these engine series are very sophisticated, dual cam, multi-valve units. All use rubber timing belts that will wear out and need replacement at some point. Only the 5VZ-FE is listed as an interference engine but, as good preventive maintenance, all of these engines should have the belt replaced at 60,000 miles.

We don’t always see these cars for maintenance timing belts though, since some people are not in the preventive maintenance mindset and don’t bring in their vehicle until something is broken. A timing belt failure, in these cases, is usually a belt that has stripped off the teeth at the crank sprocket, due to too much slack. But, just adjusting the belt tension on the early models without the hydraulic tensioner can be a chore.

One look under the hood of a V6 Camry can be a bit intimidating as far as repairs are concerned. The rear spark plugs are difficult at best, at least the first replacement time, before you’ve figured out where you can put your hands through the tight places. The timing belt replacement is tight as well but, after the first few jobs, it becomes somewhat routine. The trucks also are a little difficult at first but become much easier with repetition. In this article, I’ll try to give you a couple of tips to ease the timing belt replacement process and make these repairs on flat rate with time to spare.

THE PROPER PARTS
Before we get started on the repairs, let’s take a few moments to discuss the merits of getting the correct parts, whether you choose OEM parts or aftermarket equivalents. At our shop, we have pretty much exclusively gone to using OEM belts on Toyotas, and most other Japanese cars as well. Tooth design, shape and fit are critical to making these repairs last.  Most of the OEM belts also have very helpful alignment markings that eliminate a lot of the guesswork in getting everything properly aligned. The carmakers also make upgrades from time to time that may not make it to the aftermarket suppliers until a flaw starts to cause failures.

Seals and water pumps should not be taken lightly either. Because the water pump is driven by the timing belt on all of these engines, it’s also expected to last the life of the belt. Make sure the pump turns freely, and shows no signs of leakage or looseness, if you are going to gamble on it lasting through another belt. The seals should be of the same material as the original. I always like to look at them closely for correct design and, if they’re imprinted with size markings, I make sure that they are the same.

GETTING STARTED
I have always advocated disconnecting the battery before doing engine work; that is at least until recently. With the growing number of electronics, stereos and alarm systems that are installed on vehicles today, sometimes disconnecting the battery is more dangerous and potentially damaging than the safety concerns. Put a note in the windshield cautioning others not to start the car while it is being worked on, and then be extra careful not to let anyone mess with the car while you’re working on it. In our shop, we have laminated notices just for this purpose.

Removing the radiator on truck models, while not absolutely necessary, will give you more working room and also prevent damage to the core during repairs. A thorough inspection before starting the job will give you an idea of whether or not you will need to replace oil seals or the water pump during the timing belt replacement to resolve leaks.

Also look closely at the valve covers for leakage, as there are some overlapping procedures that will save you time.  If you do notice oil leaks, don’t forget to look at the PCV valve and hoses for blockages. Usually, the accessory belts will be getting a little ragged too, so replace them to avoid having to remove them later when they make noise after being disturbed. On trucks, remove the skid/splash panel, and on cars remove the belt splash guard in the right fender well.

CAR REPLACEMENT PROCEDURES

1. Start by moving the power steering and coolant reservoirs out of the way. On most models, you can leave the hoses attached and still get them out of the way far enough to complete the job.
2. You may also have to disconnect and move the ground wires from the engine to the body and also unclip the wiring harness from the upper cover to get the cover out.
3. Remove the "dog bone" from the strut tower and motor mount, and then remove the right-side engine mount. The bolts for the mount bracket are difficult to loosen, but they don’t need to be removed to get the bracket out of the car. Just back them out until the bracket is loose and pull out the bracket and bolts at the same time.
4. You may need to slightly support the engine to get out the mount brackets between the engine and body, if the front and rear engine mounts have sagged.
5. Pull the accessory belts and remove any brackets that will interfere with removing the lower cover.
6. Remove the upper timing belt cover, and do a little inspection. The first thing to check with the crankshaft timing mark lined up, is whether the cam marks are where they should be. These cars will run fairly good with one cam one tooth off, but they won’t run correctly. When properly timed they usually run smooth as glass. I use the time-honored method of painting all the necessary alignment points with a paint pen or with correction fluid from the office.
   Note: Doing this makes completing the job faster and more reliable, since the marks are sometimes difficult to see, especially on the rear cam. On the cam marks, I also paint the inside of the sprocket where it lines up with the inner cover because, especially on the rear cam, it’s easier to judge alignment that way.
7. Next, put the car up and remove the crank pulley bolt. I think removing the bolt with an impact gun is OK. I sometimes have to use a puller to remove the pulley if I can’t "walk" it off with a couple of prybars after spraying it with penetrant. If you do this, use care because you don’t want to damage the plastic cover. A flat bar puller with two 8mm bolts works just fine.
8. On some models, you’ll need to remove the crank sensor to get the cover out. On early models, loosen the spring tensioner or remove the hydraulic tensioner by alternately removing its two bolts, then inspect it for leaks and make sure the shaft hasn’t come out too far, indicating an internal failure. Put the tensioner in a vise or press and slowly depress it until you can put a small hex wrench or hardened wire pin through the holes in the pushrod and housing.
9. Pull off the old belt, check the idler pulleys for free movement, replace the water pump, if necessary, and replace the oil seals. One note of caution on the cam seals. We have seen cracked front cam journals, especially on the rear cam, due to the lack of access to remove the old seal. There is no "trick." I’ve used numerous different seal pullers with some success. You’ll just have to use what you can to carefully pry out the seal without putting too much strain on the housing. If a seal just won’t let go, pull the valve cover and loosen the cam bearing cap to get the seal out. It’s better than cracking the cap and causing a bigger leak.
10. Align all of your marks to both the engine and the new belt, and put it all back together, leaving any slack on the tensioner side. You may need to "tension" one of the cam sprockets to get the belt to align.
11. Reinstall the covers, including the seals, to keep out water and dirt.
12. Reinstall the crank bolt using a suitable holder on the pulley and torque it to the proper spec. Instead of using the sometimes-supplied "stick on" belt replacement tag, I usually paint the date and mileage on the cover with my paint pen. This method has proven to be much more durable.
13. As soon as you have the covers and accessories reconnected, start the engine and make sure it starts and idles properly, and then shut it down and recheck your work.

SIENNA VAN PROCEDURES
Perform all of the procedures above, and note that you will need to remove some additional parts to gain access. The procedure will depend on your agility and willingness to work around components. There is more than double the flat rate time allotted for doing this job on a Sienna when compared to a Camry, and you will need some of it to complete all the necessary procedures.

TRUCK PROCEDURES
As I noted earlier, you’ll be way ahead if you pull the radiator for clearance. Just work the cost of the coolant into your estimate.

1. Remove the fan and upper water outlet. You’ll need to pull the accessory belts and the fan drive assembly, and possibly move the power steering pump, to make room to get the covers out.
2. Remove the upper timing belt cover, and then check your timing mark alignment and make the appropriate marks with the paint pen. The truck models are much easier when it comes to realigning everything.
3. With the radiator out, you can get a small 1/2-inch or heavy-duty 3/8-inch impact wrench in place to pull the crank bolt.
4. Early trucks use a spring-type tensioner - loosen the adjustment bolt and pry it out of the way. Later models use the same type of tensioner as the cars and you will need to inspect and depress the tensioner as above. There is a special tool available that will depress the tensioner on 3.4L engines without having to remove the tensioner. This will save some time as long as the tensioner is obviously not leaking or damaged.
5. Inspect the water pump, idler pulleys and the tensioner pulley for free movement or noise, and replacing as needed.
6. Remove the old belt and install the new one and recheck the timing marks for alignment. The belts are a tight fit onto the sprockets and you may need to put a little tension on the left sprocket to get the alignment correct. It’s always a good idea to turn the engine over by hand at least two full turns and then recheck belt alignment and tension, and look for any signs of binding.
7. Reinstall the covers. Note that replacing a damaged cover at this point will prevent parts from coming off and getting stuck in the belt, or letting debris in that will do the same.
8. Do a quick start up to check that everything works, then reinstall the accessories, belts and radiator.

FINISHING UP THE JOB
Timing belt replacements are good jobs on most cars. Don’t hesitate to suggest replacement at 60,000-mile intervals, even when the manufacturer may suggest longer intervals. A broken belt will be an inconvenience and can even be dangerous if it happens on the highway. Of course, the replacement of a water pump will almost always include the replacement of the timing belt. In our shop, we quote the job with the water pump and accessory belts, and factor in the time and money for seal replacements, deducting what isn’t used. We usually order all the parts ahead of time so they are on hand if we need them.

I hope this article will be of help when one of these cars finally comes in for some needed maintenance. All too often, when they do, it’s usually because the belt has finally broken. This is a good time to educate the owner on the benefits of regular maintenance and preventive repairs that can save the tow bill and ensure a little peace of mind.

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