Rear diff locking up??

[SubieDaddy80]

Hey everyone, having an issue with my 95 Legacy Wagon 5-spd. In the morning after it has sat all night, the Soob turns tight just fine with no issues. Once I have driven it about 20 mins, I go to make a sharp turn into a parking spot and its very hard to get it to roll into the spot. I have to give it a good amount of gas and it feels like I am really forcing it to go forward. The same thing happens when I am backing up. It almost feels as if the rear end is locking up in a non-posi way. Like I said this only happens when the drivetrain is warmed up. It does not do this first thing in the morning when taking it out of the garage. Any ideas? Possibly low on rear diff oil? Bearings? Bad CV axles? I definately dont want it to seize on me or worse. Thanks everyone!

 

By they way, the new job is going great!!

[Fairtax4me]

Your center diff is shot. Search Torque Bind to get some more info.

 

That's not a hard fix on the manuals. The transmission doesn't have to come out of the car. New parts ain't cheap though so plan on making a junkyard run.

 

Are your front and rear tires the same size? Tread wear even?

[SubieDaddy80]

Not the news I wanted to hear but thats ok! Just gives me another reason to get under the Soob. lol. I will go ahead and start searching for info on the Torque Bind. Havent dealt with that yet so this is a first for me.

[idosubaru]

if it's totally failed, which it sounds like it is, you can also pull the rear section of the rear driveshaft and run it'll just run as FWD since the rear output will just be spinning. will save all that binding stress throughout the drivetrain while you plan to fix it.

[Gloyale]

The VC can be replaced with the trans in the car.

 

It's pretty easy....just expensive unless you got another junker trans around you can scavenge from.

[SubieDaddy80]

So about how much am I looking at for parts??? Give me the high and low numbers(Pull-a-part & new). Also, how long could I get away with pulling out the rear driveline and running it in 2WD? Thanks

Edited August 17, 2010 by SubieDaddy80

[WoodsWagon]

Pulling the rear driveline isn't a good idea with a 5mt, even if the VC has failed, it's still a differential and it will try to let all the power go to the disconnected rear driveshaft. 4EAT's are a FWD tranny with a supplemental rear drive, so removing the rear driveshaft is fine.

 

Your VC (viscous coupler) is a limited slip device on the center differential. When it heats up, it's meant to bind and give you 4wd. The problem is that as they fail, the heat of normal operation starts to make them bind. To fix it, make sure you fix the origional problem first, either mis-matched tires, wrong differential ratios front to rear, or if it was towed with 2 wheels rolling and 2 locked to the tow dolly or truck. Then replace the center differential. It's not a bad job, the hardest part is usually getting the shifter yoke to come off the shift shaft on the tranny, there's a double roll pin and then the yoke is often rusted onto the shaft pretty good.

 

You can source a center diff from any 1990-98 subaru AWD 5mt, so impreza, forester, legacy, and outback variants are all available. Depending on the junkyard, you should be able to get one for 50-100 bucks. You can buy them rebuilt for $350 i think the last time I looked. It took 3 hours to do the last one I did, but we weren't working hard, and there was a lot of goofing around and shooting the ************ while we were ripping it apart and swapping them out. Having a lift helps a lot, doing it in the driveway on your back would suck.

[SubieDaddy80]

Ok, sounds like I am going to head out to pick-a-part this week then and see if I can grab one. Is there anything to look for on the parts car VC that would tell me if its another bad one before I pull it out and install it on mine? Also, does anyone know a good place in WA to get a rebuilt one if I have to?

[wally]

i don't know that there's any way to identify the VCD as "bad" in a junkyard vehicle. pretty much russian roulette going that route.

[Fairtax4me]

Yeah not much way to see if it's bad other than being able to drive the car.

Luckily it's not a difficult swap, just time consuming.

 

When you remove the center diff the output shaft has to come out with it. They both just pull straight out though so it's pretty easy. Getting them back in is a trick, if you cock the bearing at all in the bore it will hang up and won't seat all the way. use plenty of fresh gear oil on the bearing race and the inside of the bore on reinstall to help it slide in easier.

[SubieDaddy80]

Been doing some thinking and I figure that what I am going to do is just take the Soob out of comission for a while and do everything I need to with it at once. I have to do the cam seal and a new clutch set anyway so I may as well just pull the tranny. So this may have actually worked out better than I thought! Another question, can I access the rear cam seal with the trans removed and engine still in the car??

[Olnick]

Rear cam seal? Or do you mean rear crank seal?

[SubieDaddy80]

Woops, I need to proof read more! Yeah, crank seal! Thanks Olnick

[Fairtax4me]

Chances are the crank seal is fine. If you have a leak it's about 99% going to be the separator plate. ("Lets make it cheap so it leaks and make it completely unaccessible so it's a royal PITA to fix!" [/ Subaru engineering dept. discussion])

 

Yes, it can be done with the engine still in the car.

[SubieDaddy80]

Sounds like a plan!