deanbrown

Hi all,

So I had 20 years and 155K miles on the 99's original timing belt, and changed it this week. I heard that they can break at around 150K so it was definitely time. It seems a credit to lexus that even after this long, the belt looked pretty much brand new and seems to have very little wear, though I know that that is no predictor of future happiness. Anyway I thought I'd post a couple of pics. I wanted to confirm that the belt is internally nylon, rather than steel, so I cut through it to see - and yes it has a fibrous nylon interior.

The bearings were worn and made a bit of noise, and felt a little rough when I turned them in my hands. (They were squeaking a bit before replacement). The water pump bearing was still nice and smooth.

I had the Aisin kit from Amazon installed, and the car is now dead quiet and runs beautifully. I hope it will last me another 150K. (lol there's an LS400 on ebay now with 450K miles, though it does have a bad transmission).

Hope that helps someone.

nvturbo

I will be tackling this job soon. Did you get the Aisin TKT-030 kit too?? I ordered mine from RockAuto and it was cheaper than most places I've looked at.

deanbrown

The kit I bought was this: , here at it's $163
I didn't do it myself, I got ACDelco to do it. I did do a 96 LS some years back but it took soooo long that I just don't have the time to do stuff like this any more, sadly!

nvturbo

Gotcha. I double checked the difference between the one you used versus the one I purchased. Even though they look the same, the 021 is for 1998 - 2000 models. For a minute there I thought I bought the wrong one. LOL

Losiracer2

I'm going on my 99's 2nd timing belt at 151k. It was done at the dealer at 90k in June 2005. I feel like after reading your story and looking at the belt that's in similar condition, I could go 90k without worry, or another couple years at least until I hit 180k. My car also came from a similar midwest climate (Dublin, Ohio) so it wasn't exposed to any hot ambient temperatures like in the West and Southwest.

I wish Blackstone labs, that does the oil analysis, also could do something similar to rubber components such as belts and give their longevity too.

mikaelse

I did my cambelt etc on my LS400 1995 at 20 years old and 95k miles. The belt looked like it would have lasted a bit longer. I did it DIY as soon as I bought the car. Would never wait that long myself. Some bearings for the serpentine belt really needed to be changed. On my other LS400 1998 I am working on changing the cambelt etc after 9 years and only 25k miles. Much because I have not worked on it and want to "feel" all the stuff in engine front for health. Sealed bearings and 22 years now is a very long time. I want it to be reliable as a DD.

timmy0tool

iTrader: (7)

thanks for sharing. I agree the belt can last well above 100k but I would not risk it. lots of factors contribute to the longevity such as ambient temp and humidity, among mileage, driving conditions, and bearing life.
I've heard of idler pulleys seizing first, knocking out the belt in the process. glad you took care of this required service!

what I regret not doing when doing a TB/WP change was to do the cam/crank seals! did you do them?!

nvturbo

IMO, those 3 seals should be replaced while you have everything exposed. Even if they look good, it's a safe precaution to do so. For me, I'm just waiting for the 2 cam seals to be delivered before I start to tackle this DIY.

mikaelse

I did not do the seals . The areas were bone dry on my 1995 with no leaks. Stil good after 5 more years.
On the 1998 I am working on now I am going to have a look and then decide. I will have the 1998 in winter storage for another 2.5 months.
They say that doing the cam seals on a 1998 is a bit of a hassle?
Another note:
Just because I was curious I dimantled the serepentine tensioner bearing seals. It made a quite dry faint hissing sound when spunn.( Bearing is standard and ca 8$ new with rubber lip seals and C3 (larger) play)
Stil worked well and no large play and no rust or degradation etc really inside. The grease inside however had turned to a black paste over the years. Texture like small pieces of quite soft but dry cheesy.
Not really sticking to the surfaces. My best guess is that it would start to be really noisy after say 2-3 years time and then fail. Probably giving some audible notice over a tankful or so ?
This would mean a breakdown life of say 25 years and ca 150.000 miles. Mostly because of the age in my opinion.
I am now starting to be a bit uncomfortable with other sealed ballbearings still working ok. Like
Freewheeling bearing of AC-compressor, Bearings in Generator, Fan bearings. Wheel bearings. Ventilation fan bearings etc.
I will make a habit of listening to those a few times a month or more .
Perhaps I have to get used to that 2025 may be "best before" date for the 1995 LS400. Ouch.