Drivetrain rumble/vibration sc400-basics done
09-28-02, 08:05 PM
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Drivetrain rumble/vibration sc400-basics done
For everyone with vibration/harmonic/rumbling issues while underway.
I have an SC400 (1992). NO rumbling until a driveshaft replacement by dealer in 2001. yet another new shaft was installed a few months after the first, no benefit. Car is great until 60ish, wherein rumbling/vibration begin ( includes buzzy rear-view mirror, seat bottoms, harmonic droan in cabin, etc... Peaks at 80ish, seems to go away at 90+.
Work done to date includes installing rebuilt 3rd carrier (rear-end)twice!, new engine and tranny mounts in 2000 (dealer), bushing inspection during complete rebuild of rear-end ( half-shafts cleaned, inspected, repacked and rebooted, new wheel bearing ( not Lexus part though), rotors, calipers, brake fluid, tires/rims check for deformaty in all three areas ( circumference, out-of-round, and trueness - balance) , bushings inspected ( incl. carrier)... in 2002...
Someone referenced half-shafts in another thread... HUMMM..
How about non-lexus wheel bearing?
The droan makes it very unpleasant at 80ish, the speed I usually cruise at when I am loafing it to San Diego.
Of note: I did not have any of this until the new driveshaft was put in behind the rebuilt trans. Lexus told me they not only do have the equipment to check on X and Y angles ( tranny output shaft angle, Center bearing carrier positioning, and entry angle to the pinion gear), but also stated that they do not have access to the parameters related to the car in the first place. Perhaps I was just more aware of things after I picked the car,,, Heck, at this point I would agree that I offended some Greek God or somesuch...
I have had issues w/ custom one and two piece custom driveshaft installations before - so similar....
but the half-shafts, the bearings...
I am fishing ... ANY Bites?
Mike
I have an SC400 (1992). NO rumbling until a driveshaft replacement by dealer in 2001. yet another new shaft was installed a few months after the first, no benefit. Car is great until 60ish, wherein rumbling/vibration begin ( includes buzzy rear-view mirror, seat bottoms, harmonic droan in cabin, etc... Peaks at 80ish, seems to go away at 90+.
Work done to date includes installing rebuilt 3rd carrier (rear-end)twice!, new engine and tranny mounts in 2000 (dealer), bushing inspection during complete rebuild of rear-end ( half-shafts cleaned, inspected, repacked and rebooted, new wheel bearing ( not Lexus part though), rotors, calipers, brake fluid, tires/rims check for deformaty in all three areas ( circumference, out-of-round, and trueness - balance) , bushings inspected ( incl. carrier)... in 2002...
Someone referenced half-shafts in another thread... HUMMM..
How about non-lexus wheel bearing?
The droan makes it very unpleasant at 80ish, the speed I usually cruise at when I am loafing it to San Diego.
Of note: I did not have any of this until the new driveshaft was put in behind the rebuilt trans. Lexus told me they not only do have the equipment to check on X and Y angles ( tranny output shaft angle, Center bearing carrier positioning, and entry angle to the pinion gear), but also stated that they do not have access to the parameters related to the car in the first place. Perhaps I was just more aware of things after I picked the car,,, Heck, at this point I would agree that I offended some Greek God or somesuch...
I have had issues w/ custom one and two piece custom driveshaft installations before - so similar....
but the half-shafts, the bearings...
I am fishing ... ANY Bites?
Mike
10-04-02, 11:18 AM
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I can't say what the problem, but as an engineer
it definatley is a VIBRATION problem.
The drivetrain has what we call a resonace
problem , same as tuning fork. It is out of balance,
and when it reaches that frequency, it vibrates at its worst and
once you go past that , it tapers off.
You will need to be counterbalanced, or realigned.
it definatley is a VIBRATION problem.
The drivetrain has what we call a resonace
problem , same as tuning fork. It is out of balance,
and when it reaches that frequency, it vibrates at its worst and
once you go past that , it tapers off.
You will need to be counterbalanced, or realigned.
03-20-12, 05:09 AM
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i have the same problem freeway speed when i let off gas or when i let off gas then lightly hold accelerator i can hold the hum noise, took a look under the car at work trans mount look old but no crack same for engine mounts but noticed cracks on driveshaft isolators
02-14-13, 07:29 PM
#4
I too am having similar issues. I have the resonance that stops after about 75 mph. The car also has a noise when taking off and slowing down to stop. Also there is a clunking sound under the console when you let off the gas and then again when you accelerate. 97 SC400 with 102k miles. Car feels a little shaky when I start it up also.
Any suggestions??
Any suggestions??
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