A scraping-rumbling-knocking orchesta of noises was coming from the left rear axle of my Loyale. Using info on this board, (thanks!:-) ) I decided to check the castle nut. It was, indeed, loose so I decided to tighten it. As I was tightening the nut, I noticed the shaft was starting to move too. The tighter the nut, the more the shaft turned with it. I decided to put the car in 4wd to stop the shaft from moving. When I finished tightening the nut, I got in and drove it and VOILA! No more noise! Nice and quiet! I finished the drive and started putting my tools away...and then it occured to me.

The wheel was on the ground...yet the shaft was turning with the nut:confused:

I realize I am a relative newcomer to Subaru...am I missing something? Splines, maybe?

Am I driving a 3-or-less-wheel-drive-car?

TIA,

-Louis-

'91 Loyale 4wd 5spd Wagon

That's normal for a differential. There are 3 "terminals" (inputs or outputs) on a differential. If you use any one of them for an input, it will attempt to turn the others as output. Since you were turning the left rear shaft, it was sending "output" to the center drive shaft (until you put it in 4WD and "locked" it to the engine).

 

Once the other 2 outputs were immovable (right rear wheel on ground, drive shaft locked to engine) you could tighten the castle nut. We normally think of the drive shaft for input -- with the two wheels on the ground, there's only one thing that can happen: the differential makes the wheels turn. A good thing :-)

 

'Course, this doesn't apply to a LSD. And only for a manual 4WD shifter. I'm not all that familiar with the push-button type....... Which do you have?

 

As for the loose castle nut, did you peen it in? Don't want that happening again. It's good you found the cure!

 

-- Mark

I think what he meant was that the shaft was turning inside the hub as he was tightening the castlenut. And the tire wasn't rotating meaning the axle was not connected with the wheel if it could turn without the wheel turning. Am I correct? If this is the case I am baffled as to why that axle could spin freely inside the hub like that. It should be locked to the wheel and not spin unless the wheel/hub was spinning.

 

--GoatBoy--

Well that would certainly explain his concern..... I'm baffled too.

 

I don't know why I didn't see that in the original post, guess I was lookin' for an easy explanation :-\

 

-- Mark

If the car was run with a loose enough castle nut, the splines in the rotor would be carved out and no longer fit with the splines on the axel. Replace the rotor and as long as the splines on the shaft are cool you should be too.

Very true. Could have just vibrated itself smooth! Not going to fall off just no bite left in the splines.

 

--GoatBoy--

Shoot! I was afraid you guys would say that. I guess I gotta pull it ALL the way apart. It wouldn't be so bad if there wasn't a snow storm within hours of hitting us.

Guess I can get by in FWD...maybe hitting the 4wd button in a pinch. Thanks Guys:headbang:

-Louis_

'91 Loyale 4wd 5spd Wagon

Just yank the rotor of and see if the splines are worn out inside there. If the axel splines are still good just throw on another rotor and you're gold. Use a pipe wrench to keep the axel from turning and wrench off the castle nut.