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2gen Outback rear diff noise

Posted: Tue Nov 09, 2010 4:08 pm
by foxx510
Hoping someone here might be able to help a bit. I have a '98 2gen OB and the rear diff appears to be getting pretty loud. It's not a whine as such, but more of a growl, kind of like a noisy exhaust would sound.

It's not the exhaust though, it starts around 40km/h and gets annoying around 80. There is about 2-3mm of slop on the input shaft and a reasonable amount of up and down slop on output shafts. The diff gets almost too hot to touch after about 30mins of driving, it's uncomfortable to touch after about 20seconds.

The car has done about 230k km and a lot of that would have been heavy towing.

So I'm not sure if it's just the diff bearings or if the gears are worn. If it's stuffed, what donors can I grab a second hand one from? It's an r180 right? 3.7 ratio?

Thanks for any advice :-)

Posted: Tue Nov 09, 2010 6:10 pm
by vincentvega
R160 - and the ratio should be printed on a sticker on the diff.

Posted: Tue Nov 09, 2010 6:27 pm
by foxx510
Thanks, I thought it was an R180 but you are correct, R160. I was way out on the slack on the input shaft, would be 3mm play max. Output shafts have about 1/2-1mm slack up and down between the bearing retainer and the shaft. Can I pull one from a liberty of a similar year if I can't get one from an outback? Is that growl typical of a dying r160?

Posted: Wed Nov 10, 2010 7:02 am
by foxx510
I'm starting to wonder if this could be a rear wheel bearing, not the diff. I can find a huge amount of references to bad wheel bearings and noise, but bugger all about bad diffs. Will do some more investigating today.

Posted: Wed Nov 10, 2010 6:46 pm
by yarney
I would put money on wheel bearings i thought mine was the diff too but did the bearings and it stopped

Jan

Posted: Wed Nov 10, 2010 6:49 pm
by AlpineRaven
vincentvega wrote:R160 - and the ratio should be printed on a sticker on the diff.
There is no sticker on the diff on Gen 2 Liberty/Outback, they were dismissed in Gen 1 Liberty series.

FYI - gen 2 Liberty and Outback manual has 3.7, automatics has 4.11.

My money would be wheel bearing as I don't believe it would be the diff on its way out...
cheers
AP

Posted: Wed Nov 10, 2010 8:54 pm
by foxx510
Thanks folks. I'm going to do the rear bearings, just hoping the hub is ok or it's another $220! I'll probably get the dealer to do them, bit worried the 200k trek will do damage but I don't have a lot of options. I'll report back when it's sorted. Thanks for all the advice :-)

Posted: Wed Nov 10, 2010 10:39 pm
by GOD
Have to ask - does the diff have oil in it?

Dane.

Posted: Thu Nov 11, 2010 12:46 am
by seagull
Just get on the RS liberty forum , some one near you will have a diff $150.00 $200.00 tops

Posted: Thu Nov 11, 2010 7:17 am
by foxx510
I tried to check the diff oil but couldn't crack the level check nut. It should be fine, it either never had oil in it or it still does because there's none on the car from leaks. I would have expected the sound to change getting on and off the power if it was the diff but it's constant and only changes with speed. There is now slight high frequency vibrations through the car too, ie buzzy vibrations at certain speeds.

Posted: Mon Nov 22, 2010 6:31 pm
by foxx510
Took the car to the Subie dealer today and they replaced the drivers side rear wheel bearing and all is good again. Only just made it, the whole car was buzzing for the last 10km or so. For others diagnosing a similar problem, the sound is kind of like really chunky 4wd tyres on a highway, or being in a light aircraft. Yep, was getting pretty loud!