Hello,

Car has 140K miles on it, and runs well overall. I replaced the front passenger and driver axles a few months ago with remanufactured axles,  which growled for a while and settled in over the months and are pretty quiet now. In the box was a slip of paper that mentioned I may need a new transmission mount since the new axles were stiffer than the old ones and could push back on the transmission, or something to that effect, which I just remembered as I type this.

In the last two or three weeks I started hearing a faint ticking noise, which only happens when I am accelerating, or going uphill. It's speed is matched to the tire speed, not the engine speed. If I take my foot off the gas, the sound stops immediately. The sound has gotten louder and louder, and is now easily audible. I have been searching the threads here but don't seem to be able to find the right search terms. I have seen suggestions in other threads on different vehicle types it might be a bearing in the front differential, a bearing in the transmission, the U joints in the driveshaft. I would like to fix the car, and pass it down to my son when he is old enough to drive in a couple of years. I was planning on putting the car up on jackstands this weekend and looking over the drivetrain to see if anything is visible. 

What could be causing this?

Thanks,

Alex

 

 

A likely suspect would be your 'remanufactured' front axles.

It could be that the joints on those axles have worn in a way that you hear the ticking sound when the axles are loaded, but not when the axles are unloaded.

Less likely but possible- small exhaust leak where the pipes meet the head.

1. axle - the inner joint.  as a "free test" you could swap the axles from side to side and see if the noise changes.  or try to regrease it and see if that helps, it may be lacking sufficient grease.
2. front diff

Subaru axles last the life of the vehicle and should be rebooted.  www.car-part.com for $15-$35 axles and reboot them.

i lost count of how many bad aftermarket subaru axles i've seen and are a complete waste of my time.