Got around to replacing the timing belt in the SC. A pretty straightforward job and I added some notes and pics to assist those that would either like to do things themselves and/or save the $700+ dollars. This is more of a reference thread in order for others in the future to refer to as I doubt many will read it and then want to run out and do this.
An improper timing belt installation will result in severe engine damage. Do not attempt if you are not comfortable and skilled to tackle such a task.
This is not a 100% detailed installation post but will guide those that already have some level of automotive repair background.
A few notes:
1) The radiator DOES NOT have to be removed though the fan shroud assembly should be (10 minutes max)
2) Align the timing marks BEFORE removing the old belt.
3) A powerful impact wrench is highly recommended. No more than 7 3/4" long.
4) Time, 4 hours for those with the right tools and experience, 8-9 hours for the novice.
5) Since your in there ,might as well change the water pump.
6) Recommend replacing the tensioner rollers as well. Two of them (not pictured below).
1) 14mm,12mm ,22m, 10mm sockets.
2) 17mm, 14mm open end wrenches
4) Powerful impact wrench
5) Gear puller
6) Small allen wrench
The number one question I get to this day from my GS days is ,"How do I remove the crankshaft bolt?" My answer: Use a compact and powerful impact wrench-see below. Keep in mind that the bolt should be torqued back on so one should be familiar with the torque settings on the impact wrench.
The belt I am using is a Goodyear GatorBack timing belt: part number #40298. Cost me around $22.00 with shipping ( I get discounts, don't ask).
Anyhow, here are some pictures with a few notes. Feel free to ask any questions.
Line up the crank pulley first.
Two ways to do this. This is where it gets confusing:
Lexus method: as the motor sits at TDC the left camshaft (as you sit in the car) is spring loaded and can (will) spring counter clockwise with the timing belt removed with very little effort.
TDC means the marks on the camshaft line up with the I on the housing of the camshafts (as seen in pics) and the dots on the crank pulley match the dot on the oil pump (see below) and the harmonic balancer notch is on 0. To prevent this spring loaded camshaft from moving, Lexus calls out to place the notches on the camshaft on the T and the crank pulley 50 degrees ATDC. This is marked on the plastic cover with a dot (see pic). This is to remove the belt and also keeps the camshafts in place where they are not prone to moving with the slightest pressure. Once the belt is removed then move the gears manually and individually over to TDC which is I on the camshafts and notch to notch for the crank pulley. The reason for this is that there is no mark on the oil pump for 50 degrees, only for TDC.
Some prefer to line up everything on the I from the start and finish that way and not move the gears individually. The choice is yours.
Same for the right side.
A/C compressor does not need to be removed, just moved out of the way. 3 bolts hold in in place.
Removing the idler pulley bracket
Remove the power steering pulley to allow the alternator to be moved out of the way. This is needed to remove the bracket behind.
OK, this is the big one. Note: Take no shortcuts here. Some try to wedge something into the flexplate gear located in the bellhousing. There is potential to cause damage and that is one thing you do not want to have to repair as the labor involved is more than the timing belt.
The Lexus repair manual calls for a special tool (read: expensive) that attaches to the pulley. Again- not my cup of tea as one would still have to use a breaker bar and much force to loosen the bolt.
My method: One big bad impact wrench.
In this case I used a very nice Central Pneumatic Earthquake 1/2" with 625lbs of max torque at 90psi( I recommend this). I ran it at 130psi. Shhhh, don't tell them as anything over 90psi is not covered by warranty so says the little card in the box.
I am normally a Ingersoll Rand fanboy but this thing is awesome. Available on sale from Harbor Freight for $80.00! The crank bolt came loose within 1 second. Note: There is very little clearance between the back of the impact and the radiator-look at the pic. Do not try to remove the crank pulley all of the way or the impact will wedge into the radiator. Just loosen it. The benefit of using this method is that it works, it is much safer vs the other methods, does not move the pulleys, and requires very little effort on my part. In other words, I'm tired, lazy, and just want the tools to do the work for me.
Look at the photo and notice the timing marks are not lined up. This is for a pose shot showing the impact wrench in place as well as showing the available room between it and the radiator. Obviously I am not going to hold a camera in one hand and remove the bolt with the other. This was just a pose shot taken before the bolt was actually removed. Once lined up the pulley will not move with a high torque gun.