2000 Tundra 4.7 Timing Belt Project

[fatboydj]

Can someone tell me what size seal drivers I need for the camshaft(s) and crank seal when I change out the timing belt. I bought a set of seal/bearing drivers and want to be sure I have the correct size drivers. Also, will a harmonic balancer puller work to remove the crank pulley once I get the bolt off? Any special tools needed to perform the complete job of replacing the timing belt and the other recommended 90K service items associated with this project.

[ah64d1]

First, I wouldn't start this job until you have all replacement parts on hand. If you have the parts on hand, just look at the new seals and you will be able to tell what size driver you need. I did not have a driver or a socket big enough to fit just inside the outside diameter of the camshaft seals, and with the crank shaft extending so far out for the pulley and all there was no way I was going to get any kind of driver on it. I opted for a drift and hammer and just patiently tapped around the seal until I had it in. It took a bit longer than if I had a driver, but same result.

For the crank pulley I used a two armed puller. I had to thread the bolt back into the shaft a few turns to give the center pin of the puller something to push against (the head of the bolt) since the center of my puller has the exact same thread as the bolt and just wanted to screw into the shaft instead of pulling the pulley off. I was lucky the threads were the same or I may have stripped the crank threads while I was playing around. But once I got the puller tight I gave it a few taps with a rubber mallet and it slipped right off.

The only special tool I bought for this job was a spanner wrench for holding the camshaft pulleys while removing/installing the bolt. These pulleys are like cheese graters once you get the timeing belt off and the camshaft likes to spin about a third of a turn with very little force due to engine compression. I had the spark plugs out so I could turn the crank easily when I was lining up top dead center which may have made the cams even easier to turn. Not necessarily good when you don't want them to move from TDC. Anyway, I did not have a lot of luck holding the cam still while torqueing the bolt with the spanner wrench. I ended up using a large chisel which fit nicely through the spokes of the pulley to wedge against the engine behind it. Do not try to hold the pulley by the tab that sticks out from the outer edge closest to the engine because it breaks off easily. These are used as interrupters for the camshaft sensor mounted on the left pulley. It appears that the pulleys are interchangeable and both have the tab but only the left one is used. (At least my engine is running well with the tab broken on the right one!)

I will also add that the Haynes manual did not mention the metal shield mounted behind the pulleys. These need to be removed to access the cam oil seals.

[zlathim]

Originally Posted by ah64d1

These pulleys are like cheese graters once you get the timeing belt off and the camshaft likes to spin about a third of a turn with very little force due to engine compression.

They spin because of the force of the valve springs, not engine compression.

[MEvang]

Just curious, why are you changing seals if they are not leaking?
Mike

[davis3903]

I was wondering that my self. if it anit leakin' don't break it open!

[ah64d1]

Because when they do start to leak by the time you find it the timing belt is probably going to need replaceing, and it all has to come out again to replace the now leaking oil seals anyway. Just insurance.

And yep, it is valve springs not compression causing the cams to spin, thanks for the correction.

[fatboydj]

What size is the crankshaft bolt head? I think maybe 24mm. Also, is the thread a right or left (to tighten). Should I by an impact socket or trust my thinwall Sears socket which can be replaced if it fractures under the stress.

[MEvang]

Originally Posted by ah64d1

Because when they do start to leak by the time you find it the timing belt is probably going to need replaceing, and it all has to come out again to replace the now leaking oil seals anyway. Just insurance.

I don't buy this reasoning. If these seals aren't leaking at 90k plus, its a very good chance that they will make the next 90k. Modern seals aren't the leak problem that seals of the past used to be. Any tech wanting to replace seals that show no signs of leaks is ripping you off ( unless there is a known common problem with a particular vehicle)
But when replacing them you increase your chances of leaks greatly. Seals tend to cut groves in the shaft they are sealing, also a coating of crusted oil can build up on shaft on the inside. If the new seal installed rides across this grove or is pushed into the oil crust it will leak. Further more many of these seals are not made to be pushed in and are laid in when the caps are installed. Driving them in peals off the outside rubber and it will leak. If the lip roles over it will leak, if the presser spring comes off the back it will leak. If the seal is distorted from driving it in, it will leak.
The point here is, the chances of causing a leak is much great then the probability the original seal will fail.
Think about this, is it really worth it.
Mike