ForrestY33

Here's my 2 cents: I would be interested if anyone can produce a link on this or any forum of evidence that a timing belt has ever failed on a LS430. Although it's an interference engine, the hydraulic tensioners ensures the belt is always within the proper tension, so the likelihood of timing belt failure, regardless of age/mileage is very, very slim. In fact, the water pump is probably more likely to fail before the timing belt and how many of those have actually failed? Most people change the water pump along with the timing belt, which makes sense because it's right there and easy to change, but it really should be the other way around. Wait for the water pump to begin failing, then change the timing belt while you're at it.

Jabberwock

I have been researching and reading forums on LS430 topics for 4+ years and have not seen any reference to a TB failure on LS430. Doesn't mean they don't happen but they may be rare - either because the TB is very durable or the typical owner of an LS maintains the car better than average - or combo of the two. Or we don;t see the info because its not posted - average owner may not be online active based on the demographic involved - many of of folks that own LS430 are not exactly spring chickens.

Gene01

I had the TB, etc. changed on my '91 LS400 a year ago with about 140k miles.
The belt had minor cracks, etc. but could probably have gone another 100 k.
Since it is a non-interference engine, I didn't worry about it.
One contributor to the LS400 forum (I think he is a moderator), had a TB fail because the water pump seized and broke it. That's the only one I can recall on either the LS400 or LS430 fora.

BradTank

I definitely think people are overly paranoid about the timing belts, which is why for my car, I never plan on changing it before the recommended mileage, even if the "time" factor outpaces the mileage.

As far as what climate you live in, I'm not sure it matters much since it's attached to the engine, it's basically going to be exposed to high heat it's entire life.

I wouldn't risk it on my own car, but I'd be willing to make a substantial bet that you could easily go nearly double the recommended mileage without any issues.