Timing Belt Replacement 97 LS400

As I recall, the Lexus V8 of your car's vintage is an interference design. That means expensive valve damage if it breaks. Rule of thumb is to change timing belts at 60,000 miles. You can get away with going longer, but with an interference engine, if the belt goes you will be very unhappy and deeply regret waiting.

We had our '92 done at the Lexus dealer a few years ago. The price was around $500. You can get it done for less at an independent, but you may not get any croissants or a car wash. It's a gamble.

Timing belt replacements are an interesting topic. I have a 93 LS400 with about 112,000 miles on it, with the original belt. But, I plan to get it changed in the next 500 miles or so because of my mechanic's guidance to me. BTW, my mechanics are an independent shop, not a dealer. Davenport motor company in Plano, Texas--highly recommended for Dallas readers here.

Anyway, they have been in business for ten years or so, and tell me that they have NEVER actually seen a timing belt break--it is always the water pump seizing up and burning through the belt in their experience. So....they focus on the water pump wear and its associated mileage, and change out the timing belt the same time they do the pump. But, water pump failure is the bigger concern--not the belt as far as what they think will fail first. They also recommend always putting a new water pump on whenever the belt is changed, since the increaseed tension, etc. of the new belt sometimed will deal the death blow to an already weakened water pump bearing.

My two cents....

Errrr... I think we're talking about two different things here. Isn't the water pump driven off the serpentine belt (the same belt that drives the power steering pump, alternator and air conditioning compressor)?

The tim>Timing belt replacements are an interesting topic. I have a 93 LS400 with

Looks to me as though the water pump is driven by the back of the belt. See the whole process here:

Thanks for the info, the correction - and the nifty link -

Good info in this thread. I'd go by mileage, not age (unless mileage/year was very unusually low) and replace when Lexus recommends for this particular model (e.g., 90K).

- Mark

I had a Toyota Celica and the timing belt broke at 62,000 miles arrgh. (Actually it shredded) so it does happen. I must be one of the 0.01% unlucky guys.

snafflekid