'98 LS400 Crankshaft Pulley Question
#1
Driver School Candidate
Thread Starter
'98 LS400 Crankshaft Pulley Question
This is my first post and I'm not at all a car whiz, but have done minor things here and there. My son is driving our '98 LS400. For full disclosure, his college roommate (who works on his own truck) helped him with the first repairs listed below, saying he'd done this before:
• Serpentine belt was replaced in February. Alternator was replaced in April (it was faulty).
• The serpentine belt broke last weekend, which we replaced.
• The crankshaft pulley was out of alignment, as in "behind" the others pulling the belt towards it. The rest of the pulleys seemed to be aligned.
• We did a very quick start. The crankshaft pulley was vibrating a bit, or at least not rotating smoothly like the others. We ran the engine for less than 10 seconds.
My next door neighbor, who has rebuilt engines, and does all his own work to his 4-Runner, said it looked like it might be loose and need adjustment. I thought I'd post here for any tips anyone can offer before calling my mechanic.
Thanks!
• Serpentine belt was replaced in February. Alternator was replaced in April (it was faulty).
• The serpentine belt broke last weekend, which we replaced.
• The crankshaft pulley was out of alignment, as in "behind" the others pulling the belt towards it. The rest of the pulleys seemed to be aligned.
• We did a very quick start. The crankshaft pulley was vibrating a bit, or at least not rotating smoothly like the others. We ran the engine for less than 10 seconds.
My next door neighbor, who has rebuilt engines, and does all his own work to his 4-Runner, said it looked like it might be loose and need adjustment. I thought I'd post here for any tips anyone can offer before calling my mechanic.
Thanks!
#2
Pole Position
This is my first post and I'm not at all a car whiz, but have done minor things here and there. My son is driving our '98 LS400. For full disclosure, his college roommate (who works on his own truck) helped him with the first repairs listed below, saying he'd done this before:
• Serpentine belt was replaced in February. Alternator was replaced in April (it was faulty).
• The serpentine belt broke last weekend, which we replaced.
• The crankshaft pulley was out of alignment, as in "behind" the others pulling the belt towards it. The rest of the pulleys seemed to be aligned.
• We did a very quick start. The crankshaft pulley was vibrating a bit, or at least not rotating smoothly like the others. We ran the engine for less than 10 seconds.
My next door neighbor, who has rebuilt engines, and does all his own work to his 4-Runner, said it looked like it might be loose and need adjustment. I thought I'd post here for any tips anyone can offer before calling my mechanic.
Thanks!
• Serpentine belt was replaced in February. Alternator was replaced in April (it was faulty).
• The serpentine belt broke last weekend, which we replaced.
• The crankshaft pulley was out of alignment, as in "behind" the others pulling the belt towards it. The rest of the pulleys seemed to be aligned.
• We did a very quick start. The crankshaft pulley was vibrating a bit, or at least not rotating smoothly like the others. We ran the engine for less than 10 seconds.
My next door neighbor, who has rebuilt engines, and does all his own work to his 4-Runner, said it looked like it might be loose and need adjustment. I thought I'd post here for any tips anyone can offer before calling my mechanic.
Thanks!
The rubber dampening ring between outer half (pulley) and inner circle side ( crank mounted inner circle) may have separated.
Very unsafe and can cause a lot of damage if it comes undone.
Do not drive until you verify.
Use correct tools to extract. (If the last person removing the balancer did not use correct tools or used the starter as an impact may have created the separation).
Refer to my post.
By the way....use only OEM harmonic balancer...
Last edited by YODAONE; 05-29-18 at 03:00 PM.
#3
Driver School Candidate
Thread Starter
Harmonic balancer and "crank pulley " are used interchangeably.. they are one and the same assembly.
The rubber dampening ring between outer half (pulley) and inner circle side ( crank mounted inner circle) may have separated.
Very unsafe and can cause a lot of damage if it comes undone.
Do not drive until you verify.
Use correct tools to extract. (If the last person removing the balancer did not use correct tools or used the starter as an impact may have created the separation).
Refer to my post.
By the way....use only OEM harmonic balancer...
The rubber dampening ring between outer half (pulley) and inner circle side ( crank mounted inner circle) may have separated.
Very unsafe and can cause a lot of damage if it comes undone.
Do not drive until you verify.
Use correct tools to extract. (If the last person removing the balancer did not use correct tools or used the starter as an impact may have created the separation).
Refer to my post.
By the way....use only OEM harmonic balancer...
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txwriter (05-29-18)
#5
Pole Position
Odds are agains a timing belt lasting 21 years...especially one with over 90,000 miles..
Mileage on your '98?
If timing belt service was performed, then removal of the harmonic balancer...and there are extremely few mechanics, dealer or otherwise, that use proper tools to remove and, or, install harminc balancers...
(have had friendly arguments on this forum on not using the starter to loosen crank bolt)
However, most use the starter as an impact to loosen crank bolt...tightening is another matter.
A Lexus Dealer I queried said they use a chain.. (wrapped around pulley)...which tears at rubber dampening element)
Very few technicians I trust to touch my car...even then I have to verify upfront whether they possess correct special service tools...amd the service managers all take offense.
Last edited by YODAONE; 05-29-18 at 05:30 PM.
#7
Driver School Candidate
Thread Starter
Mileage is 199K, so I know we're due for timing belt too. That was changed at the 90K service at the dealer, so I guess (hope) the harmonic balancer was changed. I was told we'd be good until 200K so I hope that was accurate.
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#8
Pole Position
However, the harmonic balancer must be removed when replacing timing belt...
Whether it was removed properly or not, it seems you have identified the problem.
Just be sure the mechanic does not use starter as impact wrench to loosen crank bolt and verify correct tools are used (ask to see the tools) to install new harm onic balancer;
See:
https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/863812-stop-using-your-starter-as-an-impact-wrench.html
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Horsepwr
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06-18-09 08:12 PM