Car:  1995 Impreza 2WD/FWD 5 speed 1.8    75K on the car.

     History:   Had to replace a CV axle due to a boot tear. The axle was "seized" into the hub. I had to pull the entire assembly and take it to the shop. Even the professions at the drivetrain shop could not press it out. I replaced the hub/spindle and had new high quality bearings pressed into it, bought an O'reilly's rebuild axle and installed it all. 

   Issue:  I have since this repair had this rhythmic/speed related knocking from that side. It does not appear to be outer CV noise that is typical in a worn out outer joint. ( I know that noise well). It's a uniform sound and the tone does not change ....just the speed. It seems to match tire rotation speed.  It sounds more like inner joint. It's less obvious when the car is warm, after a few miles. No drivability issues, just noise. It's not getting worse and I have 1500 miles on the car since this repair.

• Noise is much louder with "medium" accelerator applied" and turning sharply to the right and if you turn sharply to the left, (even with power) noise disappears. 
• It NEVER makes a noise even in turns, when no power is being applied. NONE. It's power applied related.
• Inner CV seems to feel a wee bit loose on the tranny splines, even though the pin is in there and all is assembled well.  

     Could this be the tranny differential? I 'm thinking I will just pull and replace the axle and see if that eliminates it.

So frustrated!

Thanks!!!!

 

 

  

I had a similar issue on my 03 Forester, a grinding noise when starting from a dead stop in first or second gear.  Didn't make the noise in reverse or after I got above 20-30 mph.  The axle that was installed was a cheap auto parts store one.  I pulled the axle out and when I tried to pull it out of the transmission the inner joint separated leaving the stub shaft and inner axle housing in the transmission, the axle separated into two pieces.

Long story short, I put in a new Cardone Special axle and noise was gone.  I didn't have time to search out an OEM one to reboot so I gambled with the Cardone Select on as Cardone had the contract to rebuild Subaru OEM axles.

if you want to hassle with further diagnosis - swap axles left-to-right and see if the problem follows.

factory manual says not to torque axles nuts with weight on the wheel - in the air, put a big screwdriver in a rotor vane and buck-up against the brake caliper, or, find some way to torque axle nut in the air.

16 hours ago, SUBARU3 said:

 

• Noise is much louder with "medium" accelerator applied" and turning sharply to the right and if you turn sharply to the left, (even with power) noise disappears. 
• It NEVER makes a noise even in turns, when no power is being applied. NONE. It's power applied related.
• Inner CV seems to feel a wee bit loose on the tranny splines, even though the pin is in there and all is assembled well.  

     Could this be the tranny differential? I 'm thinking I will just pull and replace the axle and see if that eliminates it.

Nah - that's the inner joint of the CV axle.  Swapping axles will change the symptoms and verify.  It could be the bearing, they're supposed to be installed with a hub tamer, not a press.  If they damaged it by using a press then the bearings and hub will need replaced.  Your symptoms are classic inner CV joint issues though, the bearings can cause varying noises around turns but usually aren't so throttle dependent, that's classic inner CV stuff. 

Get a new OEM axle or used OEM and reboot it and never think about it again

If the seized axle thing happens on the other side - just take the knuckle/axle off the car, reboot, and reinstall as an assembly, no need to remove the axle from the knuckle.  I've even done them without removing the axle from the knuckle but that's probably not most people's cup of tea and is a better fit for the newer 2000+ style outer boots that last forever and don't need replaced every time an axle comes out. 

speaking of which - i think you can use a 2000-2004 legacy axle on your car, i used to use them all the time on 95-99 EJ's when I used to work on those older subaru's.  they have better outer boots and they're newer.  i don't think a FWD imp is any different so that might be a good option. 

 Good informations guys and much appreciated! I like the idea of rebooting, without taking the axle out, (if seized). I forgot to mention that the sound is also related to the suspension movement of up and down. As the wheel bounces from the road, the sound changes. 

how Positive are you that particular symptom is directly correlated to the axle change?

ive seen brand new aftermarket axles blow to pieces in less than 100 miles so I wouldn’t put any symptom past an aftermarket axle. 

 Positive..... No noise issue prior to change. It was just a torn inner boot.

Yeah - junk reman axle. Get a reman or a new axle from Subaru. 

GD

On 10/27/2018 at 3:36 AM, SUBARU3 said:

 Positive..... No noise issue prior to change. It was just a torn inner boot.

i assumed that was the case, but thought i'd verify - as i said at first, junk axle.  very common with aftermarket axles. 

So much work and then have to do it over! I just never had "inner" noise before, now I know what it is.

9 hours ago, SUBARU3 said:

So much work and then have to do it over! I just never had "inner" noise before, now I know what it is.

they don't do that very often, so it's not common or as familiar as the typical outer joint clicking. 
yep - avoid aftermarket axles. buy from subaru or reboot OEM axles.  www.car-part.com