Subaru steering vibration

I had a front axle replaced on my 2001 Subaru Legacy Wagon because the boot was broken and the cv joint was dry. After the replacement, there is a significant vibration in the steering at idle and slow speeds. The mechanic has checked it out and feels that nothing related to the axle is causing the vibrations. He thinks the vibration is caused by low idle speed. I have two questions: 1, could low idle speed cause this vibration, and 2, why would replacing an axle cause the idle speed to drop?

I don’t know why, but I just have a feeling this one is a engine mount.

The mech is right, the axle has nothing to do with a rough idle.

You may have a loose vacuum hose or perhaps a bad plug wire or plug or even a dirty throttle body.

The vibration complaint is a bit unclear.
If you’re saying a vibration is present while the vehicle is idling and at a dead stop, then a low idle speed could cause this.
Changing an axle should not affect the engine idle speed, although it could be possible if he banged into an oxygen sensor or damaged the ox. sensor wiring while changing the axle.

If you have a vibration present while moving down the road, and if this was not there prior to the axle change, it could be a faulty axle if a reman unit was used.

I’ve installed a lot of axles and can only remember one failure on a reman, but I recently ran into this with my daughter’s car.
A week or so after installing a reman halfshaft in her car she called one day and said she was having some vibration problems and wanted me to look at it. Well, she never made it to me. About 5 miles away she said the car was taking spells where the vibration increased and the car would sometimes dart to the right shoulder of the road suddenly. I went and got the car and drove it to my house although I felt a few times I was not going to make it.
The problem? The new reman halfshaft had apparently been assembled without any grease in the outer CV joint and was now trash. Lifetime guarantee part so no problem on the swap; just an irritation.

Everything on the front end was tight and so was the reman axle with no apparent problems. I finally came to the conclusion the problem HAD to be the axle and after pulling it out; voila. One could feel the joint trying to lock up at times when rotating it by hand.
Removed the boot and that’s when I discovered a “greaseless” CV joint. :frowning: