96 legacy , rear diff or ? howl coming from front right

[propane]

 

Picked up a 1996 legacy
5spd AWD wgn 142K mi, test drove it & drove it home with a real good howl
coming from right front of car, ABS, on, car seemed to wander on when coming off the gas & slowing down for stops. car had some really bad maint, scary
loose eng oil drain plug, trans was over filled.   Previous owner replaced PS pump that I can’t so far
match the missing filler dipstick cap.

 Question is where to start? The howl, matches
road speed, its not so much a low rumble, like I would think a bearing (been
wrong before). Here is what I found in the trunk: completely worn out trashed
mini spare & flat. I read Fairtaxtome previous post on 2001 outback “whats
with the bad trans? “ which I will try, jack up front wheel & see if it
rotates, listen for noise if it does turn.. then same for rear. . The other oil
leak on garage was coming from rear diff; I assume it got trashed with high
speed driving with the minispare.  Looking
for thoughts on this. 2nd question: if the rear diff(3.90 ratio)  is leaking badly, just change it out? Wonder whether it’s the front diff as well, or maybe a
wheel bearing?   thx for reading

 

[heartless]

if the bearing is bad enough it will howl. the howl and wander when letting off the gas would suggest a very bad bearing to me

 

jack up the car and check for wobble - grab tire at 6 & 12 o'clock and try to wiggle it. any movement is a bad thing.

If there is no wobble (betting there is) then try rotating and feeling for (put one hand on the coil spring, the roughness of a bad bearing will transmit to other components), listening for noise

 

rear diff can be changed out, just make sure the ratio matches the tranny.

[propane]

was wondering if a 1993 same ratio 3.9 rear diff would interchange with my(3.9 ratio) 96 ? the one in car is leaking badly.  & will try to rock wheel to see if there is bearing play thx

[ShawnW]

The rear axles aren't the same but if you use the 93 axles and rear diff I think it would work.

[propane]

Tone ring part of rotor? It turns out the drain plug for the rear diff was finger loose as well   the eng drain… This car is throwing me curve balls. I drained enough oil out of rear diff to decide it didn’t burn up from lack of oil.
It was black-a little fuzzy metal on magnet drain plug, so I think its OK. Next, in trying to track down the howl, I noticed that pulling the car in & out of garage,

 it had the drivers front brake grabbing. With both wheels off the ground, the wheel didn’t grab,(key off) & turned the opposite side OK Then I saw the ABS wheel sensor was tied off, the knuckle has been changed, to a non ABS style, the dust cover is different too. Rotor & pads are new, but I don’t see a tone ring inside the rotor, Is that part of rotor? It looks like a trip to salvage yard for correct knuckle,(w/ mounting boss for ABS sensor) Looked at Car-Part.com, many years 91-99 interchange

I figure the ABS light that would turn on (ABS system off) would release the brake grabbing, although there is a melted plastic ring on the outside of the wheel that looks like hub cap remains.Wonder if the car had been driven without the ABS  being turned off (my 91 has that issue), until the brakes are applied & the Light comes on.  Asking if tone ring part of rotor, didn’t find anything in searching for “tone “ or “ring”  some for ABS* thx,

Edited May 8, 2014 by propane

[propane]

 Done some more work, still trying to find what component is bad. Noise is coming from passenger front, loud wrang wrang wrang slows down with coming to a stop, present even at a few MPH, have driven it in a traffic circle, didn’t hear much of a change. couldn’t feel any vibration transfer w/ wheel off ground, no play  at the 12 – 6 o’clock, diff oil didn’t have any glitter in it that I could see, I replaced the opposite side knuckle w/ correct ABS one & had bearing with it, was hoping it might be a bad bearing on Pass side. Could be rear diff. or  front diff+ trans., or an axle any thoughts?  

 If I jack stand all four corners, and run it in drive, do U think having both diffs off the ground would isolate anything? thx again

Edited June 17, 2014 by propane

[idosubaru]

 Noise is coming from passenger front

 

then the issue is passenger front: 

 

1.  wheel bearing

2.  front axle - normally i'd say this is unlikely but this car has been so poorly maintained we can't really assume much right now.

 

The rear diff leaking:  if it's the rear plate, reseal it.  if it's the side axle seals, replace those.  if it's the front pinion seal, replace it. 

or replace the entire diff.

 

Car off the ground won't be loaded at all so it could go either way - it'll still be noisey, or won't at all.

[Fairtax4me]

ABS will not apply the brakes. It only releases pressure to keep the brake from locking.

Sounds like the brake caliper locked up and was dragging. Could have easily cooked the wheel bearing.

ABS tone ring is bolted to the back of the hub (round part with the lug studs). Visible with the brake rotor removed. You need a 95-98 knuckle to get the correct hub w/tone ring.

 

I hope you didn't pay much for this car.

 

If the drain plug on the rear diff was loose the fluid was probably very low. Fill it. Check the front diff oil and fill that and drive it some. Front diff dipstick is on the passenger side. Drain plug is just above the joint of the Y-pipe. Change both in about 500 miles and look for large metal particles. Some glitter/ sparkle is normal.

[propane]

 1st thx Gary think your choice of wheel bearing is (was) correct. Just finished undoing axle nut, ¾ drive cheater bar and extension, judging by the looks, nobodys been in there since OE. Glad I did -- rust, & bump & grind when I turned the innnermost inside race. Going to Car-part.com-short supply so far. I liked your use of a thermal gun from a previous post, next on my list of tools to buy.
  2nd to Fairtax enlightening to think of ABS as a “pressure interrupter “ & I wasn’t clear in my earlier posts did the fluids front &back already, as well buy a set of matching used tires & rims as a diagnostic tool. I think I’m home free, almost, what ever the pass side knuckle runs me, glad it ain’t no tranny, so far. And yeah I’m in the car for 7 plus a buck & half for parts. So far. Will post outcome when the knuckle shows up. Thx all

Edited June 17, 2014 by propane

[propane]

Closing this thread as well, I replaced entire steering knuckle on Passenger front side( where the noise was coming from) rusty, clunking bearing once off the axle, by spinning the inner race with finger.

That was the howl. as many of you correctly identified.

It still has a little gear whine in 1st, 2nd which as Fair tax said in another thread was typical based on wear.

Why did I think it was maybe rear diff? I was "snake bit" since once I changed trannies for a similar noise, when it remained, decided to change diffs (same ratio) which was back feeding its problems to the front.

Used steering rack worked out well. it bled its air out  OK Swapped exhaust quieted it down, couldn't even see the leak. This car is far more noisy & tinny sounding than my 91 Legacy LSi

 they say generals tend to fight battles based on the last war.

 No ABS light occurs (other than start up) after unplugging everything chasing electrical problem unrelated to howl

 key symptom was when driving the 96 legacy, on long sweeping curves, the howl did not change note,  as differentials let axles & wheels spin at different speeds around corners.and there should have been a significant noise change.

 still have a dragging caliper, ABS comes on only drivers front wheel when I jam the brake and barely skid only that tire. dead caliper on opposite side?  thx all for helping me keep it on the road here in Colorado, they don't rust out, and I would put the 90s Legacies up against the later model stuff for engineering and durability. Back East,   rust  finishes off many Subies.

Edited July 16, 2014 by propane

[heartless]

still have a dragging caliper, ABS comes on only drivers front wheel when I jam the brake and barely skid only that tire. dead caliper on opposite side?

 

make sure the caliper pins are clean and greased properly - caliper should slide back & forth easily with no pads installed. if it doesnt, you need to do a bit of work.

also make sure the caliper piston is working/moving properly.

had to replace the caliper on the other half's 2006 recently - one piston (dual piston caliper) was siezed up - refused to budge either way.