[fisher01]

1986 Supra, auto, 165000 miles

Trying to figure out what this noise maybe. It occurs at around 1900 rpm with speed 48-50 mph, foot on accelerator. Sounds like your blowing over the top of a bottle. At higher or lower speeds there is no humming.

If I take foot off accelerator, noise stops.
If I place car in neutral, noise stops.

Noise is intermittent. Somedays its humming, other days nothing. Occurs both when car hot or cold. Humming is very loud. Seems to originate from center of engine/car.

Any ideas?

Thanks

 

[Supra Bob]

Is the car an Auto or Manual tranny?

 

[fisher01]

Supra has an automatic transmission

 

[Angkistrodon]

I have the exact same problem except it happens around 70 mph. Also the car is a 5 speed. I think it could be the rear going bad. Or not???????

 

[fisher01]

I don't think its coming from rear differential. I'm leaning towards the possiblity of it being the center drive shaft bearing.

I don't have any experience with these and what they sound like/symptoms when they start to go.

Any other ideas?

Thanks

 

[Tanya]

here's just a shot in the dark, but why not have your fluids all checked out, and also try greasing up the U-joints? Maybe they're just old and whiney like a lot of the people on the forum, hehe j/k
Give her a lube job, hopefully it's something simple like this

 

[Dave A.]

The rear diff. is definitely good about becoming a whiner with age. :lol: The older they get, the more they whine, especially if the gear lube hasn't been changed at regular intervals. Sure sounds like it could be a bearing problem somewhere in the drivetrain. How many miles are on your car?

 

[fisher01]

Theres 165000 miles on my car. My rear differential does have a slight whine to it which I understand is fairly common. This noise is much louder and will easily drown out the whine in the rear. I agree its a bearing somewhere, but which one would act like this?

 

[Dave A.]

Strange that the noise comes and goes and sometimes isn't apparent. The rear diff. bearings in my 85 started showing signs of wear from a howling sound that eventually gets quite loud as the bearings continue to fail. Rear diff. noises can be very load dependant. Try coasting along at different speeds w/o accelerating or decelerating and see if the noise gets louder.

 

[Angkistrodon]

The Whine or Hum is always there But very quiet......Now at ~ 70 mph its a loud consistant hum when I have the accelator down.

 

[fisher01]

Well the noise returned for about 10 seconds today. I was going about 50 mph with foot lightly on gas pedal. Let go of gas, noise stops, re-accelerate to about 55, no noise.

The noise seems to always appear right under 50 mph with foot lightly on accelerator. If I keep accelerator steady, yes the noise is loud. Seems to originate right under center of dash. If I let go of gas pedal the noise will stop or if I give the car more gas the noise will stop.

Car runs well and transmission shifts fine.

 

[SupraPilot]

Same problem here...........ever so light pressure resting on the gas.at hwy speeds
Gas on or off...stops............I thought it was the new muffler my neighbor put on it b4 i got the car........... it's like...........ooooooowaahhhhh.
My rear is on it's way out anyway so i'm not sure.

I priced a center bearing at Toyota today....$251.00
....................PepBoys...............................$263.00( gofigure)
...................Strauss Auto..........................$ 180.00.

150,000 miles on mine but the bearing seems ok but i don't know how much play is allowed when you push up on the DS..........I'm doing the rear and clutch on mine so i'm going to replace the CB as well just be safe.
A worn CB will eat up a rear in no time......maybe the net will sport some competitve prices

 

[Dave A.]

Try turning the driveshaft by hand with the trans. in neutral, parking brake On, and engine Off. See how far you can turn the driveshaft without turning the rear wheels. It's not unusual to be able to rotate the driveshaft about 1/8th of a turn or more if the diff. is heavily worn.

 

[fisher01]

Well I'm leaning towards the sound coming from the driveshaft support bearing. After reading posts here and on other boards with cars that have a similar setup, it sure points to the bearing. O'Reilly Auto parts has the bearing with support for about $100.

As $$ are real tight right now, I don't want to spend $100 and then find out its something else, or more serious like an internal transmission problem.

Wonder if I could find a good used bearing cheap?

 

[85SilverWedge]

I can tell you this: I had a whine similar to what you described, acted about the same, went for the center bearing idea. Made total sense. $150 right from Toyota. I installed it, and during installation noticed the u joint on the front of the rear driveshaft kinda sucked, and the bad thing is with theses cars you cant replace the u joints, the entire driveshaft section must be replaced, or so I've read. 85-90% of my whine was taken care of, leading me to believe that the shitty u joint or worn rear end may have also been contributing. If you want an OE center bearing for $150+shipping, let me know, that $251 seems steep. I have a dealer that gives me serious discounts.