Rear diff dieing, remove rear drive shaft?

[mtnpat]

Question: the rear differential on my buddys late 90s Outback is on its last leg. He doesn't have the money to get it fixed or replaced right now, so I was wondering if removing the rear drive shaft was a good option? Would the center differential then send 100% of the power to the front, without damaging the center diff?

 

I don't have the details on year, engine, etc, but I can find out.

[idosubaru]

if the rear diff is going out it depends on what exactly is failing but if you want to keep the car driveable for sure then you'll want to remove the rear cv axles as well. otherwise the wheels will still turn the diff via the axles meaning it will still make noise and fail which could eventually mean your rear wheel won't turn. so in short, remove all three items that turn with the diff...driveshaft and two axles.

 

if it's an automatic you'll want to remove just the rear half of the driveshaft, hopefully it's in two pieces. if you pull the end of the driveshaft out of the rear of the transmission it won't be driveable as it will spill ATF all over the ground. so you only remove the rear half of the driveshaft, many soobs have two piece driveshafts. so remove the last half (connected to the diff) and leave the front half connected to the trans so it doesn't blow ATF all over the ground.

[mtnpat]

Anyone else? Just wondering if damage would be done to the center diff if rear end is disabled (driveshaft removed).

 

thanks

[idosubaru]

your center diff will not be damaged by removing the driveshaft.

 

you can pick up rear differentials fairly cheap. source a used unit and swap it out. it's an easy swap and they don't fail very often so a used unit should be golden.

 

definitely remove the driveshaft to protect your trans and center diff, but the rear differential will still be turning even if you remove the driveshaft so you'll still hear noises and reach failure at some point.

[idosubaru]

i see, no money.

 

the rear output shaft of the trans will still rotate, it just won't be turning anything, so you're not going to hurt anything buy removing the driveshaft.

 

let me know what kid of trans it is - manual or auto and if it has locking or FWD buttons, etc.

 

if it's a manual trans you'll have to lock the differential (if it has that option?).

 

if it's an auto trans you may have a FWD option like the older models? if it's an automatic you'll want to permanently *lock* duty solenoid C which will lock the transfer clutches. this will turn the rear driveshaft similar to a locked differential, but it will only spin the output shaft since without the driveshaft it won't be connected to anything. some models have a FWD Fuse but i'm not sure what that does and wouldn't really want to drive the car very far like that.

 

the biggest thing is that you want to leave something in the output shaft of the trans (definitetly if it's an automatic) or you won't be able to keep fluid in the tranny. driveshaft may have two pieces - just remove the rear half connected to the rear diff.

[NorthWet]

EJ-based should have AWD, so no PB for 4WD, etc.

 

My 91 Legacy has a 2-piece driveshaft, but the rear portion is not removable like an EA82's is. (It does nopt have bolt-together flanges at the center bearing.)

[blackbart]

If you remove the rear diff on a manual car it may not move at all. I am currently parting out a 90 Legacy with a manual tranny. Sold the rear diff and removed the rear axles. I went to drive it out of the way and it didn't move. I can hear the drive shaft flopping around but the car just sits there. I did the same thing with an auto and was able to drive it away. This was yesterday (Sunday) I posted a question about this in the drivetrain section at LegacyCentral.

[idosubaru]

on a manual you have to be able to lock the center diff (with a button or diff lock turn on some how). if you can't then like he said it will transfer all the power to the rear and just spin the rear output shaft.

[Lverano]

if the rear diff is going out it depends on what exactly is failing but if you want to keep the car driveable for sure then you'll want to remove the rear cv axles as well. otherwise the wheels will still turn the diff via the axles meaning it will still make noise and fail which could eventually mean your rear wheel won't turn. so in short, remove all three items that turn with the diff...driveshaft and two axles.

 

if it's an automatic you'll want to remove just the rear half of the driveshaft, hopefully it's in two pieces. if you pull the end of the driveshaft out of the rear of the transmission it won't be driveable as it will spill ATF all over the ground. so you only remove the rear half of the driveshaft, many soobs have two piece driveshafts. so remove the last half (connected to the diff) and leave the front half connected to the trans so it doesn't blow ATF all over the ground.

I wanted that answer for my current thread, glad it was on here.