Doing Your Own Timing Belt

[Oregon John]

Doing the timing belt on my SC430 [2003] took much longer than with lesser cars, but was worth the savings.

I'm not going to address IF you should do it, just my experience with one. I have worked on cars for many years.

NOTE that a number of things did not conform to the Lexus manual.

PLUS I made a tool to remove the crank bolt easily, for $15. More in a bit.

First: It is not necessary to remove these items that the book thinks you have to: vane pump which is horrible to get off, so don't. [but do take off the pulley]

-- The AC compressor - just remove the lower bolt and loosen the top one.

-- the crank position sensor [leave it alone]

-- the RH belt pully can stay; it just tilts back anyway.

-- Furthermore, it is not necessary to use a special tool [sST] to remove the old timing belt. Just remove the tensioner [2 bolts]. You likely want to replace this anyway - check the specs on how much pin is showing. Likewise on putting in the new belt - just put in the tensioner last.

-- For new belt, set the two cam gears as per book, i.e. slightly rotated.

Watch out for the positioning of the various dust shields, and which goes in front of what. It's easy to lose track of this and the book is not clear.

Removing the crankshaft bolt can be difficult; even my excellent Ingersoll Rand impact wrench couldn't budge it. The SST is expensive. Instead, I bought a 2 inch wide flat metal bar, 3/16" thick, from the hardware store. Length is not vital, and I left mine three feet long. I bored three holes in one end. Two small ones [big enough to admit the 8mm bolts that fit the pulley*] are not so hard. But the center one that admits the 7/8" socket is bigger than most guys can do at home with this

thick steel. Mine was 1-3/8" so I paid a friend who has a mini-machine shop in his garage to do it. Measure your pulley well for the center-to-center figures. For the removal of the big bolt, I pointed the long bar up at an angle, and had it rest against a 2x4 I had laid on top of the motor. The I used a 5 foot cheater pipe on the 7/8" socket, and it came off without a whimper. Same on re-install. BTW, get this bolt off BEFORE the old belt removal.

* Beware of using 8mm bolts that are too long and interfere in back. I used hardened ones that came with a puller set.

Notes on "http://www.shastaanesthesia.com/Lexus/"

This site has some good info, including how to open some of the tricky electrical connectors and service limits on the timing belt tensioner [which is in a remote place in the Lexus manual].

BUT - beware of page 10. It wrongly shows photos of the timing belt lined up with the weird "T" marks on the cam gear back plates. This would encourage the repairer to set the belt this way, and that would be wrong. They are correctly lined up with the marks just to the left of those T's. That's why the factory manual never shows it that way [on the T's].

Furthermore, I started to set the timing mark on the crank gear wrong, but was stopped when the marks on the belt itself didn't line up for the cam gear settings. Just above the crank gear there is the correct raised mark, but mine was covered up with old belt dust. Instead, I spotted a casting mark down there that looks like a plus in a circle. I merrily started using it! A wrong move that was corrected by going slowly and watching the belt lines.

A major issue with timing belt change is what else to change. You want NOT to get into all this again before the next 90,000 miles has passed, so DO change the water pump, even if the old one looks great. Annoyingly, there is also an O-ring to change [as per book] which is of course not included with the water pump. For the belt rollers, even though they can be had in a kit with the belt, I took the book's advice and left them in since they showed no leakage. Cautious types may elect to change them anyway, but for sure on the second belt change at 180,000 or whenever. I also followed the book and changed my tensioner since the rod was out-of-spec. The serpentine belt can also be changed during this whole operation, too, of course, as well as the radiator hoses. Why? Just to make sure they don't fail during your morning commute or on a trip.

I'm not sure why Lexus didn't use hydraulic valve lifters, but with the SC430 they're manually set with metal discs as commonly done in cars these days, and it's a good idea to check your valves when doing the belt. Do it before belt removal. That said, it's a nuisance to take off the valve covers, especially the right one. The battery has to come out [to remove spark plug coil #8], plus even after loosening the wire harness hold-downs, it's still a wrestling match. Then the final touch was that I accidentaly popped off an electrical connector - the one that controls the cam oiler solenoid. Great - this puts the entire motor in jeapardy! You can't really repair this - the connector doesn't come apart intact. This all was followed by a 1-1/2 DAY debacle to fix my boo-boo. Lexus can order the part, but clips come separately. I ended up in a wrecking yard finding a close connector, then modifying it with a Dremel, then trying to figure which wire went where..... etc.

Oh, and changing the valve discs if necessary is another nuisance yet, but luckily mine were OK.

[BuddyTD]

John...

I own a 2005, RX330 with 109K. I had my timing belt and tensioners replaced by my Lexus Dealer last week. In addition, I had the spark plugs replaced.

Today, my first time checking fluids, the inside hood latch release cable seemed to come loose inside the engine/safety latch. Of course, the hood will not open. The car is in great shape....never a problem, especially something like this.

When doing the above described work, would a dealer have to remove the cable release from the safety latch for any reason to get to the timing belt, etc.

Also, would you have a suggestion on how I can get into the engine compartment without being able to use the cable release?

I'm new to the Forum and don't know how to get to the proper area to describe the problem or find a helpful way of fixing it myself.

Thanks

Bruce

[Oregon John]

Bruce-

I can't think of any reason for a repairer to access the hood latch system in this case. For a fix, I suggest first getting your head under the dash and inspecting the release handle. Then seeing if there's any way to remove the grill from the front [this will allow manual latch release]. As a next resort, crawl under the front of the car, remove the bottom engine cover [~15 screws] and look at the cable, but it's unlikely anything would be apparent. Last resort is the dealer, but note that they may have a quick fix!

[BuddyTD]

John,

Thanks.

I just thought it strange that the first time I tried opening the hood after $1700. worth of maintenance,

Certainly wish I had the knowledge to do timing belt and plugs.......not for the average back yarder.

I hope I can figure it out myself........I'm sure if I take it back to the dealer, it's going to cost me $$$$$$$$$$$ for them to tighten a loose cable :(

Thanks again,

Bruce

[BuddyTD]

John,

UPDATE:

The weather in Chicago is pretty brutal right now. I took a quick look and figured I would leave my latch release cable to the Lexus dealer..... I FEARED taking it because I believed it to be the cable slipping loose from the safety latch. I was sick thinking this repair was going to cost at least $100 to $200.00.

When I took it in, the Lexus service rep (mechanic type who would take the first look) said let's see..... He slipped the cable end off of the back of the latch lever and gave a quick pull....THE HOOD POPPED OPEN !!! Nothing more than that.

He had the service department re-tighten the cable to the safety latch inside the engine compartment,, WASHED my car and charged me NOTHING :) !!!!!!

Problem solved ! It was a good day and it restored my faith in ONE PARTICULAR LEXUS DELAER IN THE CHICAGOLAND AREA..........

Thanks again for your suggestions,

Bruce