SilverFlare

yo,
Do u guys know should I change my timing belt now?
I got 98 LS400 with 70k

VVT-i

I will change it at 90K along with Water Pump.

meZoom!

sounds like you could wait a lil more, maybe til 90-100K. reasons:
- never personally heard of a (toyota) timing belt breaking at 70K
- you might have some other mechaical problems arise between now and say, 90K miles that makes you consider selling the car, in which case, you could save $$ by not doing the timing belt change now.

ToyLexmods

Silver,

Please do a search in the archives. I for one will not change the timing belt until it needs it. I look every oil change at the condition of the belt (takes 3 minutes to inspect the timing belt). I have monitored the belt on my parents 92LS400 with 130k and its been fine every time. Some fine hairline cracks are developing on the flat portion the TB but nothing into the cords or ribbed portion of the belt. Others have run 150, 160k on the first belt with no problems. My buddy the Lexus service manager has seen even more mileage. Will you damage anything else if the belt breaks? Na

So, my 94LS with 85k has the factory tbelt and my 92SC4 with 70k has the factory tbelt and I have no plans on changing them anytime soon. Parents 92LS w/130k...... I plan to change this summer along with all the seals, WP, tensioner, pulleys the whole works. I have all the Lexus parts sitting in the garage just waiting for summer.

kreativ

I've heard of LS owners going 150K+ on the original timing belt as well.
I'm pretty sure my '91 LS' owner's manual only says to inspect the timing belt at 90K, and in shorter K intervals after that.

hyperopt

ToyLex:

I will join you this summer as well. I have nearly all the parts to do the whole nine-yards this summer, with the exception of idlers & pulleys which I plan to rebuild with new bearings. My belt should be 140K new by then. :eek:

ToyLexmods

Hyper,

Yeah, I did hear that you could just purchase the bearings for those idlers. Do you have some information and or pics. That would be a good topic on its own.

I am glad to see others out there with the same plan. Why should I pay 1k or more for a 60,90 or even a 120k TB change just to keep those Lexus service guys eating gorumet meals for lunch. Ha, screw them....we will keep all our cars and run them each to 140k before the first timing belt change. At the current rate...my 92SC4 with 70k will need its timing belt changed in about 10 more years. Hahah

McDonough

My Father's 1992 SC 400 had the belt break at around 150K miles. The belt apparently shredded/melted and clogged up the oil pump. It was quite a mess. Oil pump assembly was not cheap. If he had changed it as I told him he should, this would not have happened. He also had a tow bill of $225 as he was around 75 miles from home.

All in all, I'd get it done before 120K miles. Change the water pump at the same time. I also believe time was a factor in this breakage, as the belt was over 10 years old.

kreativ

I've heard varying opinions on whether certain Lexus engines had non-interference or interference designs, the latter of which I'm told would result in serious damage if the TB broke. Anyone know for sure which Lexus engines are non-interference and which are interference?

tech237

early ls400's are interference engines...the newer models are not....

buuzy

Hmmm.... my SC4 has 110K on the original TB. How do I inspect it?

VVT-i

I think you got it backward. The 90-94 LS are non-interference engine. In 95-97 LS Lexus decided to get 10 more hp by used the dome type pistons and that become the interference engine. The 98+ with VVT-i also interference engines.
The SC400 are non-interference engine until 96 or may be 97 with the engine from the 95 LS.
The ES300 are non-interference engine until 99 with VVT-i engines.
On the interference engine I go with timing belt, water pump and tensioners at 90K.
On the non-interference I go for 120K, but it's depend on personal preference too. I like to do it earlier especially if I have a long trip in the near future and the car is close to the recommendation for the timing belt.

PERRYinLA

In other discussions on the "when to change timing belt" controversy, I've been saying I've have yet to come across a post where someone had first-hand experience with a timing belt breaking. I might have to start revising that statement, but maybe not. It remains a very rare occurance, even in cars that don't follow the recommended replacement schedule.

Plus, in one of the other few times I've heard of a belt breaking, it was the water pump that failed and locked up, shredding up the timing belt (that's not the belt's fault!). I don't know much about the oil pump assembly, but maybe in McDonough's case that failed first as well.

In any case, while towing is no fun (but is often free with some insurance policies or a AAA membership), his father still came out ahead economically. He made it to 150k miles and only paid for one timing belt change (plus some extras, admittedly), while someone following the more conservative recommendations would have sprung for 2 changes by about now.

97LS400

The LX 4.7 liter v8 is the only interference engine in the Lexus lineup, at least up to year 2000. Here is a link to the Gates timing belt chart:

http://www.gates.com/downloads/downl...TOKEN=83555645

I inspect my 1997 Lexus when I clean the distributor and rotor contacts (every 15k) and will replace it when it shows the first sign of cracking or other unusual wear.

On any make/model of car where the labor to replace the t-belt is high, you want to replace t-belt driven water pump, pulleys (or bearings if you can find them,) and inspect oil seals for any sign of seepage. It is not worth the minor savings to take it all apart again a year later.

SharpLS-96

Sorry, but that gates chart is not accurate. The 1UZFE is in fact "interference" for sure. If it breaks it will do engine damage.