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AZ Mike

Questions About Replacing Timing Belt On '99 Ls400

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My '99 LS400 has a mere 63,000 miles, but is "in service" for 9.5 years. I am going to be putting a lot more miles on it than I have been, and am planning to replace the timing belt as I have exceeded the time interval by 3.5 years (even though I have not hit 90K miles).

Based on what I have read, it sounds as though these are all recommended replacements while you are in that far, even if they have not failed/show signs of wear yet:

1) timing belt

2) idler pulleys

3) tensioner

4) front crank seal (cam seals apparently are a totally different beast than on earlier year models)

5) thermostat

6) water pump

7) serpentine belt

Am I overlooking anything?

Other than the fact that my model does not have distributor/plug wires, is this tutorial the same/similar for a '99?: http://www.lextreme.com/timing.htm

What is the best/cheapest source for a factory service manual and/or access to pages for this maintenance?

Thanks, and Merry Christmas!

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Mike, I would also rebuild the starter motor while you are in that far.

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Good suggestion, but with only 63K on the clock, you'd think you could wait until the next TB. It all depends on your average commute. If they're short distances each time, then the 63K becomes a much larger number because you're using the starter more often and you might want to change it out/rebuid. If they're mostly highway miles, you could wait.

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here is a lil tutorial ive done when i was changing mine few years ago:)

http://www.lextreme.com/timing.htm

now its almost time for another change:)

How similar/different is this to a '99, which has an interference engine, no rotors, caps, etc? Does anyone know of a similar DIY for the '98-'00?

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I have all the parts, and will be tackling the timing belt on Saturday.

2 questions:

1) Is the small tube (0.5 oz) of the Permatex water pump sealant enough for the water pump, or do I need the larger tube?

2) I have seen posts referring to o-rings when replacing the timing belt. What o-rings need replacing?

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I have all the parts, and will be tackling the timing belt on Saturday.

2 questions:

1) Is the small tube (0.5 oz) of the Permatex water pump sealant enough for the water pump, or do I need the larger tube?

2) I have seen posts referring to o-rings when replacing the timing belt. What o-rings need replacing?

Your tube of permatex is plenty.

The o rings refer to one of two o rings. One on the fitment called the "water inlet housing" that goes into the block - Replace this O-ring on the water inlet housing. (Apply high temperature sealant to the groove on the water inlet housing. Within 5 minutes of applying the sealant, install the water inlet housing). Torque the 2 bolts to 13 ft-lb (185 kg-cm, 18 Nm). Connect the water hoses to the water inlet housing.

The other "Replace the O-ring on the water by-pass pipe. (Apply a little soapy water to the O-ring. The O-ring comes with the water pump).

Good luck.

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I have no plans to replace the starter. I figured that while I was in that deep that I may as well replace the water pump, pulleys, tensioner, tstat, etc. so that hopefully I don't have to do this for another 6 years. :D

I already have all the parts. I will inspect as I go. Options are to leave original parts in good condition in place and save new parts for later, OR (and my more likely choice) install the new parts, and keep functioning original parts as backups. I realize that it may be a waste, but nearing 10 years, I am nervous about the timing belt despite the low miles, AND, I would hate to have to go back that deep into everything in a year if a pulley decided to !Removed! out then. But, if there is a consensus opinion that I am an idiot for changing the pulleys, tensioner and water pump this early, I am certainly open to suggestion!!

Apparently, I missed the water inlet housing o-ring in my parts order. Factory only part, or is it just a plain 'ol o-ring that I can match up at Ace Hardware?

As for the water pump.......apply sealant to the facing metal, then on the pump flange, with gasket in between? Or is a bead not required on both sides of gasket? If both sides, it is difficult to believe that the little 0.5 oz tube of water pump sealant is enough. Then again, I am usually guilty of buying too much rather than too little.

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just to clear something up the starter install/removal requires you to remove the intake manifold. the timing belt only requires you to remove the timing belt covers. very different. you can also rebuild the starter. if you search here or on clublexus.com you will find a thread by GrandLS400 who rebuilt his starter. basically a copper contact will wear out on the starter causing it to not function properly but this copper part can be purchased individually and replaced. also remember to buy new intake manifold gaskets if you do the starter.

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OK......so I have removed four bolts, sensor, etc from driver side timing belt cover, and the thing doesn't budge. Odd, since the passenger side came off easily. Could the gasket have cemented the driver side TB cover on? Any problems with using a screwdriver as a wedge to break the seal? Or is there something else holding the cover on that I don't see in the repair manual?

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OK....realized there was a cap nut in the center of the cover that the shop manual did not reference. Doh!

Now to the fan bracket, which I am assuming is the part that the fan pulley is attached to. The shop manual says that there are 2 bolts and 2 nuts holding it on. So far, I removed those and couldn't budge it. I removed a 3rd bolt and still can't budge it. Any tips to removing the fan bracket??

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But, if there is a consensus opinion that I am an idiot for changing the pulleys, tensioner and water pump this early, I am certainly open to suggestion!!
I don't think there's any chance of that happening. I can't imagine that anyone who has spent the 5-7 hours doing this job would recommend leaving 10 year old pulleys, water pump, tensioner, etc in the car to save a couple bucks.
At what age/mileage do the starter motors typically fail?
I've owned two UCF20s, and the starters in both of them failed at ~150k miles. For my '95 (more hwy miles), that would have been at about 6 years old, and for my '99 (city miles), it was 9 years old. There must be something different about the replacement starters because the one in my '95 outlasted the original one, and it was still starting perfectly when I sold it at 315k.

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I've owned two UCF20s, and the starters in both of them failed at ~150k miles. For my '95 (more hwy miles), that would have been at about 6 years old, and for my '99 (city miles), it was 9 years old. There must be something different about the replacement starters because the one in my '95 outlasted the original one, and it was still starting perfectly when I sold it at 315k.

Do you think your results are typical Blake? Has anyone else had starter failures that early?

My '92 LS with 150,000 miles still has it's original starter, as does a friend's '94 with over 300K, and a family member's 98 with 120K.

Maybe we are all just lucky! That, or the starter design/supplier have been different from year to year.

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Only got part way into the project last Saturday, picking up again today.

The alternator needs to slide off to allow the serpentine tensioner to come off. In order to get the alternator out that far, it appears that I need to move the power steering pump as the pulley is in the way. Is this correct, or am I missing something?

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