Growling or rumble strip noise from rear of car.

[dlfred]

There is a noise coming from the rear of the car that sounds like a growling, or small rubble strips. It seems to be worse under deceleration and "seems" to get quieter when I push in the clutch and coast at speed. It has gotten worse at a fairly rapid rate. I tried to check the bearings by jacking up the car and trying to get movement from the wheel assembly, nothing there. I just recently replaced the drive shaft support bearing, it seems fine.

The backlash, measured by twisting drive shaft back and forth and looking at yoke, only moves 1/4 inch.

I don't know if the clutch could cause this type of problem but it seems to work fine, no slipping.

It really sounds like the diff or a bearing. Thanks in advance.

1986.5 Supra 3.0 5 spd

[dlfred]

The transmission shifts great. There doesn't seem to be much vibration coming through shifter. You can feel vibration through seat if you place your hand on seat while moving. So it feels like it is coming through the chassis rather than the drive-train.
That could be good news, right? With the wheels off the ground it seems to turn the diff gears smoothly. I did find one diff to sub-frame bolt loose . All the rest are tight.
I thought a wheel bearing making that kind of racket would be loose when pulling on wheel. So basically I have run out of Diagnostic Talent.

[Busted Knuckles]

Did you check for looseness at the rear diff and the pinion shaft? The pinion shaft is where the driveshaft connects to the rear differential. I've seen these go bad and create the bearing noises you hear.

[89ST]

I would also double check that the new drive shaft support bearing you installed is aligned properly. Not trying to accuse you of bad work. But the way you describe the noise makes me think that could be it?

[dlfred]

No worries on offending my mechanic skills. If the drive shaft support bearing was installed wrong, would it start to vibrate right away? It was installed in June and has been very smooth until recently. Also the bearing and carrier feel tight, I would think that it would be showing some wear with this amount of vibration. I am not sure, but I believe the noise is different from the support bearing noise.
I did get under the car and try to move the support bearing, u-joints and pinion shaft, loose bolts and could not get any movement.

I was considering draining the diff today. Is it possible to refill it without a pump?

While I am asking, I started to pull it down to check the condition of the wheel bearings. I am stuck, unable to remove the hub. I removed the 4 bolts through the backing plate will that do it?

Sadly, I have been using the online manual and still got stuck.

I will try again today.

Great input, I appreciate anyone taking the time to read and respond. Thanks

[MA70-3.0GT]

just a thought, wheel bearings dont HAVE to be loose to be rumbling. I have a rumble from the right front (due to burning all the grease out with a sticking brake!) and it's not loose just growly.

[StonecoreTx]

Check your diff and diff mounting bolts. sounds like a problem i had,ended up being the diff was old not well maintined and my subframe was cracked in various places. i had to replace diff and subframe. reinforced subframe in the process. no more noise 4 me.

1. check areas around diff like the subframe and mounting points where the diff mounts to. 4 in back, mainly the 2 in front to driveshaft. they are grade "10" blots, also check the U cradle part above the differetial "nose" to driveshaft. these areas tend to crack esp in manuals due to tq.

http://www.supramania.com/forums/sho...%28finished%29
http://www.toyota-supra.info/forums/...eleration.html

2. take rear diff bolt off, stick your finger in the hole and feel the fluid level. should feel fluid right away. if you have to feel around for oil u need a change/refill.
(also lsd uses friction additive in the diff gear oil.) drain diff oil and refill with lsd oil until it almost wants to come out of the check hole. replace plug. should run alot smoother, quieter. why not anyway.

3. with wheel bearing just get access to them, remove the bearings, buy 4 new ones and new grease, put a good amount of grease in the palm of your hand and smash the bearing into the grease in a scooping motion which forces the grease to bead through inbetween the bearings. wipe eccess then reassemble. neat trick i learned from my bro.