Lexopolis

Your screwed, you CANNOT be off one tooth or vavles will hit the pistons

randal

Just FYI. I took some pics and put together a little DIY for my 98.

Removal:
http://www.flickr.com/photos/landar/...7622883357340/

Install:
http://www.flickr.com/photos/landar/...7622886015670/

rx7guy

One year later I had to do my Jetta 'cause it died on the road. The timing belt teeth sheared off!

I was lucky it didn't ruin my engine. BTW, Jetta 4 cylinder's are a heck of a lot easier to do than Lexii.

dashan

Can some club members who did the timing belt and water pump replacement on a 95-97 LS engine comment on the difference of the replacement between 1 LS and a 95-97 engine?

Is marking the timing the same in those two engines? I am going to do mine, a 1996 LS.

thanks

bcmyers

i have a 94 sc400 this is the first time i have gone this deep into the motor... i thought i had everything lined up got it back together and it is out of time... i turn the harmonic balencer and line up the cam pulleys with the marks and put on the belt....??? timing is still off.where would the harmonic balancer mark be located when the motor is TDS..?? I EVEN TRIED taking the belt back off and lining the harmonic balancer with the 10 on the plastic case behind the harmonic balancer and reset the belt on the cam pullys... ran a lil better but still is not close to right... (in doing thjis is the 10 retarding the timing or advancing it... as i said i am no mechanic.. just trying to understand) i love this car and it is ready to go just have to figure out this timing issue..

timmy0tool

iTrader: (7)

do some more research, your answers have all been covered before. it is tight but you HAVE to make sure the timing marks align! make sure when the marks are aligned that the tensioner is set!

http://www.lexls.com/tutorials/engine/timingbelt.html

for 98-up motors, but the principle remains. study!
removal
http://www.flickr.com/photos/landar/...7622883357340/
install
http://www.flickr.com/photos/landar/...7622886015670/

CLRH2O

Honestly - I've got something to add here, as it's fresh in my mind because I'm dealing with this right now.

I also find the above (https://www.flickr.com/photos/landar...7622886015670/ and https://www.flickr.com/photos/landar...7622886015670/) humorous to the extreme because it simply DOES NOT work like that with the early year 1UZFE motors. You'd think it does... but it doesn't. Why? man.... who freaking knows!

I've been doing the timing belt and water-pump replacement the past month in the few hours here or there I can find in between *life*... and let me just tell you - EVERYTHING YOU SEE IN EVERY TUTORIAL REGARDING SETTING THE TIMING IS WRONG.

In my case I'm working with a 1993 SC400 - but elements of this apply throughout the UZFE range - and can lead to disastrous results if done wrong on the later year Interference versions of the motors. The early year 1UZFE like i have are NON-Interference and messing up the timing doesn't break anything - which is handy when you discover just how retarded this whole process really is.

If you follow the instructions that tell you to line up the white marks on the new belt with the marks and dots in the metal of the crank and Cam sprockets... when you put that hydraulic belt tensioner back on - that's it, game over, your car WILL NOT EVER have correct timing.

It has to do with the Hydraulic tensioner specifically and the fact that you cant put the belt on with it in place. The tensioner I'm speaking of is the little 5" straight metal one that is held on with two bolts from the bottom just to the side of the main crank - it pushes *up* on the assembly that the timing belt tensioner pulley is on - the one that moves (RH) not the static on the LH side... it's the only one in this system.

Anyway - apparently you're supposed to IGNORE the lines on the belt (oh... THOSE ARE USEFUL THEN!?!) and "Turn the crank off by one tooth". But which way? Well, I've heard both Counter Clockwise and Clockwise - who's right... Ugh - I don't know yet as I've not had enough time to take apart the entire front of my engine again...... Grrrrrrr.

Seriously TOYOTA/LEXUS.... SERIOUSLY?!!!!!!!

Straight up - this type of thing is beyond aggravating.

sha4000

iTrader: (1)

That tutorial is DEAD ON for the 98 and I know because I just used it exclusively for my TB job I finished a Couple of days ago. You have to make sure that the belt does not jump a tooth when reinstalling it. Believe me I know how hard it is but you have to go slow and be patient when installing the belt. I gave up a couple of times and even asked some questions here and the other lexus forum from the guy landar who posted that tutorial. I ended up installing the belt and then putting the tensioner in very carefully. I even had to take the belt back off to get a broken bolt out of the can pulley and put the belt back on the same way. I understand your frustrated but what exactly is the problem you are having?

CLRH2O

On the non-interference ODB1 1UZFE (including my year 1993) if you follow the Factory Service manual instructions - or any other instructions found around the internet including LXLS's - which state to use the alignment marks on the new belt and then put the tensioner in as the last step (and release it of course).... you will, without fail, have the timing thrown off by the tension.

The way you fix that (apparently) is to put the belt on the Crank (not the cams) off by one tooth. Again, I have to 50% chance it as to weather it's off by one tooth clockwise or counter-clockwise... because no one has been able to give me a for sure answer on that point. But hey, why not do this a 4th and maybe even a 5th time just because the process is proper bent right? ;B

From what I can tell looking at this issue from an engineering standpoint, it's to do with the valve spring relief on the non-interference 1UZ. Unlike the VVT-i models (as shown in those links above)), where the spring relief on the valves doesn't seem to be effected by this (again, not sure why exactly) - it appears that when you apply the tensioner at the end the cams are pulled counter clockwise - so when the crank is then put to TDC (or 0 / zero) after two rotations you end up with both the exhaust and the intake sides being advanced by what equates to 1 tooth at the crank. So, when you get the crank to around .... 5 degrees off (before, to the left of 0 / Zero) then the cams are aligned perfectly, but obviously the crank is not at zero.

So - that's what I can speak to so far.

And yes - it's a huge time sink tearing the whole front of your motor off each time to do this - which is exacerbated by the F'n HYDRO FAN PUMP (oh let me count the way I loath that design..) that you have to drain of it's trans fluid each time. And of course the removal of the whole fan assembly in the process. And while I'm at it - you know the top rear 14MM bolt on the AC Compressor.. the one located IN BETWEEN THE METAL FREON LINE HOOK-UPS AND THE EXHAUST MANIFOLD SHIELD... the one you HAVE to release so you can shift the compressor downward enough to let the bottom most flange of the hydro pump housing slip past the AC drive pulley in order to remove. Yeah - Top marks for that little gem 1UZ engineers... love you for that one. /me smacks forehead!

sha4000 - you have no idea how envious I am of your 98+ setup without the HydroFan pump system

You know - writing all this - I'm somewhat amazed I am able to do what I have to this car. It's really not easy stuff.

sha4000

iTrader: (1)

What is the hydro pump? This is an SC your working on right?

CLRH2O

Yes, a 1993 SC400. On these models you had a Hydraulically driven cooling fan. In place of the *fan bracket* with a clutch that you have, I've got what's referred to as the "Hydro-Fan Pump Assembly" that's driven by pressurized automatic transmission fluid flowing between that part of the system (and interestingly enough) and a second pump assembly on the back side of the fan it's self - which is attached to a cowling that's bolted to the radiator.

It's a typically over-engineered "Lexus" system - which - while a technical marvel is just a straight pain in the *** when dealing with this particular repair.

Fun Fun

sha4000

iTrader: (1)

Ok I seem to remember a thread about that fan but I don't think it was a US spec car. Japan I think.

CLRH2O

Mine's a regular old USDM left hand drive SC400. Bought new in Ft. Meyers Florida in 1993 and then bought by me in Tampa Florida in 2006.

sha4000

iTrader: (1)

You have any pics? As far as I know you should not advance ANY of the pulleys by a tooth. The mark for the crankshaft should be about in the 5 O'clock position. Of course the tensioner pulls the pulleys counter clockwise a little since the pressure is being applied on that side of the engine. Once the marks are lined up the tensioner SHOULD not make the belt move. If you can get someone to put pressure on the top of the belt while installing the tensioner. That's what I had to do when aligning the cam pulley marks.

randal

Well thanks for finding my tutorial "humorous to the extreme". That's why I took the time and pains to publish it...for your amusement.

Here's the deal. You can use the marks on the belt to get the initial alignment set. I know the OEM belts are plainly marked and if you align the belt marks with the marks on the cam pulleys and crank, you should have perfect timing. However, the REAL proof of correct timing is not in the belt markings but rather the metal stamping in the pulleys and engine. Those marks are permanent and are the ONLY ones you should ultimately use to decide if your timing is correct. I just got done with replacing a 92 LS400 belt and the timing was dead on with the stampings after initially using the belt markings to install the belt with the tensioner installed (though pin not yet pulled). After pulling the tensioner pin, we rotated the crank 720 degrees and verified that the stamped marks were exactly on. Engine ran perfectly.

I do not know why you are sounding some kind of alarm that all of this is now somehow incorrect.