Pictures: GS400 timing belt parts and part #'s. How-to soon.
09-28-07, 07:29 PM
#61
Driver School Candidate
If u guy need part for your cars let me know cause i can get them much cheaper i work for part dept. and I am allway helping other people cause i know the part can cost alot of money.. can hit me up in a message with all your info. of the car and i can also ship to where ever
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JFU99GS400 (07-12-20)
09-29-07, 11:21 PM
#62
I applaud the OP for posting this up as it does take time and it is for the benefit for everyone. Your engine is very clean and you spent some time on the project.
There are two schools of thought on this process. The Lexus method mentioned above and the one used by myself and perhaps others.
The Lexus manual does call for lining up with the T marks to remove the belt which is 50 degrees ATDC. This is to prevent the left camshaft (right if your looking at the motor from the front) from spinning counterclockwise and hitting valves (serious doubt that you would bend one anyhow at this point) .
Then the manual states to move each gear over to TDC which is I for the camshafts and the notched on the crank pulley/oil pump before installing the belt which makes little sense as the camshaft can still and most likely will move anyhow when back to TDC so why bother lining it up to T to begin with.
So in order, from the Lexus manual
1) Line up everything to TDC as pictured above in the small pics to ensure everything is lined up. This is I on the camshafts and 0 on the crank pulley (not gear).
2) Move the crank 50 degrees ATDC to match the notches on the cam to T and the crank notch to the little dot on the plastic timing cover.
3) Remove the crank bolt and timing cover and remove the tensioner ,belt,etc..
4) Move the gears over to TDC again to install the timing belt.
Again, the above is from the Lexus manual itself for a SC430-same motor.
Myself , I just lined everything up with I and the crank to 0 on the cover and notch to notch on the oil pump. It could be done either way I suppose.
See close up pictures here of the timing marks in the SC430 section from my timing belt replacement.
https://www.clublexus.com/forums/sho...=1#post2950974
There are two schools of thought on this process. The Lexus method mentioned above and the one used by myself and perhaps others.
The Lexus manual does call for lining up with the T marks to remove the belt which is 50 degrees ATDC. This is to prevent the left camshaft (right if your looking at the motor from the front) from spinning counterclockwise and hitting valves (serious doubt that you would bend one anyhow at this point) .
Then the manual states to move each gear over to TDC which is I for the camshafts and the notched on the crank pulley/oil pump before installing the belt which makes little sense as the camshaft can still and most likely will move anyhow when back to TDC so why bother lining it up to T to begin with.
So in order, from the Lexus manual
1) Line up everything to TDC as pictured above in the small pics to ensure everything is lined up. This is I on the camshafts and 0 on the crank pulley (not gear).
2) Move the crank 50 degrees ATDC to match the notches on the cam to T and the crank notch to the little dot on the plastic timing cover.
3) Remove the crank bolt and timing cover and remove the tensioner ,belt,etc..
4) Move the gears over to TDC again to install the timing belt.
Again, the above is from the Lexus manual itself for a SC430-same motor.
Myself , I just lined everything up with I and the crank to 0 on the cover and notch to notch on the oil pump. It could be done either way I suppose.
See close up pictures here of the timing marks in the SC430 section from my timing belt replacement.
https://www.clublexus.com/forums/sho...=1#post2950974
Last edited by Pearlpower; 09-30-07 at 01:36 AM.
10-11-07, 12:36 AM
#63
What would happen if i cut the belt off with a small metal cutter and have some one watch to see if the cam gear will move? Would that be better? Is this procedure so person whos removing the non broken belt, might be a chance upon removing the belt that the cam gear might move?
10-11-07, 01:28 AM
#64
Even if the cam gear moved there would be no chance of damaging anything with the car off. The drivers side cam gear moves counterclockwise and is loaded to do just that at TDC which is why Lexus recommends moving it 50 degrees. Either way does not matter provided you line up everything.
Last edited by Pearlpower; 10-12-07 at 04:58 PM.
10-11-07, 01:57 AM
#65
What would happen if i cut the belt off with a small metal cutter and have some one watch to see if the cam gear will move? Would that be better? Is this procedure so person whos removing the non broken belt, might be a chance upon removing the belt that the cam gear might move?
10-11-07, 10:18 AM
#66
So just match the crank at "0" and match both cam gear to "I" and unbolt the 2 bolts from the tensioner and just slide the belt off? So another thing is when i'm taking the belt off and just incase the cam gear moved alittle bit from the "I" mark counter clock wise do i just move it back to the "I" mark counter clock wise one full circle? If i move the cam gear NOT counter clock wise and i move it the other way is that bad? Do i just have to move it counter clock wise one full turn or is it OK to move it the other way back? I know this is asking way too much in details,but i've done belts in the past with other cars and this seems alittle complex.but i see other members accidently mess things up these engines and i can't afford to mess things up. PLease excuse me for asking too much questions.
10-12-07, 05:00 PM
#67
So just match the crank at "0" and match both cam gear to "I" and unbolt the 2 bolts from the tensioner and just slide the belt off? yes ,that is one way to do it
So another thing is when i'm taking the belt off and just incase the cam gear moved alittle bit from the "I" mark counter clock wise do i just move it back to the "I" mark counter clock wise one full circle? move it back turning it as little as possible, not all of the that way around which would not work anyhow as the valves will hit the piston and prevent this from happening,just move it back
Though timing belt replacement is critical, it is not a fragile system so bending valves would be very difficult with the motor off.
So another thing is when i'm taking the belt off and just incase the cam gear moved alittle bit from the "I" mark counter clock wise do i just move it back to the "I" mark counter clock wise one full circle? move it back turning it as little as possible, not all of the that way around which would not work anyhow as the valves will hit the piston and prevent this from happening,just move it back
Though timing belt replacement is critical, it is not a fragile system so bending valves would be very difficult with the motor off.
10-24-07, 12:53 PM
#68
Do i just match the crank on "0" and the two cam gears to "I" mark and just match the markings on the new timing belt to the cam gear marks and bottom crank sprocket marks and install the tensioner and release the pin thats holding the tensioner to give tension on the belt?
10-24-07, 01:53 PM
#69
Another thing is when removing the T-belt,Do i set the crank to 50degree mark and the cam gears to "T" mark upon removal so the cam gears won't move? Is this the correct method? Also if by any chance upon removal of the belt and the cam gear moved alittle clockwize ,Can i just move the cam gear back backwards and set it to the mark? Or do i have to move it clockwise? I know the questions that i'm asking is very "****" ,but i can't afford to mess things up. So please excuse me. Also,To move the cam gear,can i set the open wrench on the center bolt of the cam gear?
Last edited by ta1972; 10-24-07 at 01:58 PM.
10-24-07, 03:11 PM
#70
Your questions have been answered on this thread on the link I provided above.
To answer-yes-if the cam gear rotates (and it likely will) just move it back. This is why Lexus wants you to move it 50degrees-to prevent this from happening. Which method you use is completely up to you. It is a very simple process, BUT is a very critical process in that everything is lined up to prevent serious engine damage. If anyone has any questions on this PM me and I will try to answer them the best I can but I do recommend check the other thread first.
To answer-yes-if the cam gear rotates (and it likely will) just move it back. This is why Lexus wants you to move it 50degrees-to prevent this from happening. Which method you use is completely up to you. It is a very simple process, BUT is a very critical process in that everything is lined up to prevent serious engine damage. If anyone has any questions on this PM me and I will try to answer them the best I can but I do recommend check the other thread first.
Last edited by Pearlpower; 10-24-07 at 03:46 PM.
10-24-07, 06:20 PM
#71
Pole Position
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heres a list of things u should also change when doing this project and just get all of this out of the way
camshaft seals
idler pulleys
valve cover gaskets
spark plug tube seals/ grommets
might as well do these while your getting at all of that ....
hope this helps ...
aloha
camshaft seals
idler pulleys
valve cover gaskets
spark plug tube seals/ grommets
might as well do these while your getting at all of that ....
hope this helps ...
aloha
10-24-07, 06:54 PM
#72
Lexus Champion
I'm not sure about the cam shaft seals though. If you want to remove the camshaft seals on these 1uz, You would have to remove the cams to get them out. The VVT-I seals are big. This is one of those deal "If it doesn't leak... Don't replace it".
JPI
JPI
10-24-07, 10:55 PM
#75
Last edited by dung0981; 10-24-07 at 11:01 PM.