My 1999 forester might have a problem. 3 weeks ago I replaced the rear driver side wheel bearing. At that time, I could not spin the tire, it spun but only until the axle caught up with free play of the drive train. All three other tires were on the ground. I assume this amount of rotation is normal. The wheel bearing install went well and it's nice and quiet. Today I put on my summer set of wheels and tires, while this wheel was off the ground, all others on the ground, this wheel/tire spun freely with no resistance. Nothing feels sloppy or unusual. The axle shaft spun with it.

Is there an issue here?

Thanks.

Auto or manual trans?

if you have no issues it's probably normal.  

 

it's an open rear differential right so the tire should be able to spin freely?

If an auto and no rear limited slip the driveshaft should spin fairly easily with just one rear wheel off the ground even if in park, if a manual I'd expect a bit of drag even if in neutral since the center lockup mechanism would be trying to spin the fronts.

It is an automatic.

 

 

Why wouldn't it spin 3 weeks ago while doing the wheel bearing?

was the parking brake engaged? maybe it was and you backed-off the star wheel to remove the rotor???? seems like u would recall disengaging the handle afterwards though.

 

weird

If it had been sitting for a bit the plates in the clutch pack may have been stuck together a bit.

Or maybe the E-brake was inadvertently on?

Or was it started and idling?

Or maybe that one day the rear limited slip decided to actually do something?

 

But, not a symptom of any problem as far as I can tell.

It is an automatic.

 

 

Why wouldn't it spin 3 weeks ago while doing the wheel bearing?

 

Well, from your description the important change between the 2 times you checked, is that the other rear wheel was off the ground. I'm assuming this time that the other rear wheel spun when you tried it (if not, you had some kind of failure happen in those 3 weeks, but I find that highly unlikely).

 

Something else to keep in mind, is in an Automatic transmission Subaru, with the engine off (transmission not building fluid pressure), the AWD is basically disengaged. So the driveshaft can spin in the rear of the transmission by hand regardless of what the front wheels are doing, or whether it's in park.

 

Considering those factors. I think one of 2 things is happening, depending whether you have a rear LSD or not.

 

Most likely, you have a car with a rear LSD (AFAIK, Forester S models, but I could be wrong. If you want to pm me the last 8 digits of your VIN, I can look it up and tell for sure). With both rear tires in the air, they both spin the same direction, and so does the driveshaft. But no major resistance. But with that other rear tire on the ground, you would have to overcome the LSD, which is not really possible by hand.

 

If not, when it's in the air, the path of least resistance is for the other rear wheel to spin the opposite direction, and the driveshaft not to move. But with one rear wheel on the ground, an open diff should allow one tire to spin, while there is some resistance on the driveshaft, normally easily overcome by hand. But, it's possible that you have something not allowing the transfer clutches to release (rust/corrosion on the drum, etc.). You would definitely have drivetrain binding when driving it, if this were the case.