Impala Forums banner
1 - 7 of 7 Posts

· Registered
Joined
·
23 Posts
Discussion Starter · #1 · (Edited)
Long story short, I've had this vibration at 60mph-ish and its only when accelerating. I just recently had 4 new tires put on and it did not fix the problem. It didn't make it worse either. So after doing a little searching, I came to the conclusion the CV axle was at fault on the drivers side. I've also noticed a grinding noise when turning left and the vibration feels like it's left front. Almost like a brake pad indicator riding the rotor type of sound. Speaking of which, I did just put new rotors / pads / hardware on the front about 3 months ago.

Tonight I get the axle and yank it all apart. The first thing I noticed was how loose the axle nut was. I had soaked it with seafoam deep creep about an hour before trying to loosen it and it more or less just broke free with very very little effort... The lug nuts put up a better fight. So with that, I'm thinking oh maybe it was that causing the issue. I figured I would try to pull the axle anyways to inspect it and... I couldn't get it out. I need a different pry bar because what I have isn't working. I wiggled the joints around and it felt okay so I'm having doubts it's the CV shaft. I put it back together and tightened the nut to 156ft-lbs plus another little oomph with the breaker bar.

It drove fine. No issue and the vibration is about 90% gone. Just feels like normal engine vibration to me. But with that now I'm wondering two things.

Loose axle nut = very little bearing pre-load. This is never good, so I'm wondering if that is making the grinding sound. Although, I never felt any grittiness while spinning it by hand. And it only makes noise turning left.

Second... how does an axle nut just come off that easy? Did the vibration cause the nut to back off?

Thoughts, opinion, what would you all do from here?

EDIT / Update:

So I drove the car all week since I made this post. The vibration hasn't really changed but I noticed today it was more on the passenger side. I yanked the wheel, checked the axle, took the entire brake assembly off and inspected everything... All looks good. But... I do have quite a bit of axle play (at the transmission, not the CV axle) that the drivers side does not have. I can get a video if possible. The seal is still good, no leaks. So I'm thinking the play is normal.

The nut on the passenger side was tight tho. I took the drivers side back apart and inspected again. Nothing out of place, all looks good. Nut tight, bearing feels fine.

I'm thinking it's either a diff bearing, axle on the passenger side or something else?
 

· Registered
Joined
·
23 Posts
Discussion Starter · #2 ·
Update:

I put in a new axle on the passenger side. Play is a lot less now and the vibration is a little better. It's not 100% better, but it's an improvement.

While I was in there, I noticed my engine mount was done... So I'm going to replace that here soon.
 

· Registered
Joined
·
3 Posts
Update: I put in a new axle on the passenger side. Play is a lot less now and the vibration is a little better. It's not 100% better, but it's an improvement. While I was in there, I noticed my engine mount was done... So I'm going to replace that here soon.
The vibration is from the worn engine mount on passenger side and possibly transmission mount on driver side. They are fairly easy to change if your handy with this type stuff. Drive your car to double check this is the problem, I'll bet the vibration is only while you are accelerating. When you let off gas it will stop. Hope this helps. YouTube videos are your friend.
 

· Registered
Joined
·
3 Posts
Also if the play in the axle was rotational, like if your spinning the wheel and feel play it is normal. The only thing you should be worried with axle play is side to side like if you grab axle and can move it left and or right or if it's making a terrible sound when you make a turn. If this wasn't the case I would take it out and put my factory part back in and return the one you bought to the parts store. Theirs is probably aftermarket junk and will fail a lot quicker than the factory original. But if you don't feel like doing that job again I understand but I would keep original axle and ask a friend that knows a little if it looks OK and reuse it again if it's still good. Might save you some money one day. One other thing. Order the trans mount and motor mount together on rockauto.com and only buy factory replacements. Like Acdelco or Delphi. You will find out its way better to spend the extra on them instead of doing the labor several times with aftermarket parts.
 

· Registered
Joined
·
23 Posts
Discussion Starter · #5 ·
Sorry, be a little bit since I check up on this.

So if you are staring at the differential (where the axle slides in) the old axle had (what I would consider) excessive play left and right AND up and down. Just a guess on my end, but I would say 0.125" from center in all directions would be the amount of play I felt. Rotational play was normal tho. I loaded the transmission with a breaker bar on the lugs and tried rotating the axle (rotationally) and there was zero play.

When I got the axle nut loose on the passenger side (which it was very tight) and free from the hub. The axle was very loose, but didn't have any play. Similar to an inner tie rod when it's worn out. It just kind of flops around, and new they have some resistance to them.

I got the axle out with out any real issues and got the new one in. The new axle did however feel very much tighter than the older one. There was still play left and right / up and down but it was much tighter. Almost like the spines were worn?

Either way, it didn't solve the issue. The passenger side engine mount is however an issue. It's not a mount anymore to say the least lol. The trans mount looks fine however. Either way, seeing how it has 253,442 miles on it I think it would be best to just change them all at once. Changing the lower engine and trans mount without changing the upper mounts just seem like it would tear them apart quickly.
 

· Registered
Joined
·
3 Posts
I would agree with you. That sounds like the mounts being loose could have cause the axle to wear out too. But yeah I would change at least the 2 bottom mounts and if the 2 top ones are worn at all I would do them too. You don't have to but might as well like you said. I did each mount with putting front aluminum sub frame on jack stands and using a big piece of wood to disperse the load put jack under corner of trans pan and raise everything enough to change mounts thru one wheel well at a time with the wheel and tire removed. It's fairly easy just takes a little time and effort. Hope this helps you out some.
 

· Registered
2015 Impala Limited 9C1 🚓
Joined
·
49 Posts
yeah bad mounts will be a huge contributor to vibrations.

another thing to look at is checking the inner tie rods. Pretty much any joint or piece of rubber should be treated as suspect until you inspect them.
 
1 - 7 of 7 Posts
Top