I am looking for some advice. I put a 2.5 AS on about a month ago. I also added 275/65/20 Nitto TG's. I have been thoroughly pleased over all. No issues with anything for two weeks and perfect balance and ride with the new shoes. I also had my diffs flushed and refilled about a week or two ago. Since then I have noticed an increasing vibration while making hard turns from a stop. It is worse going right than left. I feels like the tires are rubbing, but there are no signs of that. I was thinking wheel bearings? I am at a loss.

Any help or suggestions are appreciated.

 

so you had the diff's flushed and re-filled? did they use the correct fluid? did they add the friction modifier?

 

Fluid replaced to factory specs. I don't know on the Friction Modifier. I also verified the correct torque on my lug nuts since the tires were new. CV angles seem okay. No torn boots or fluid leaks either. I am at a loss.

Thanks for your input. If you have any other ideas try me.

 

Alright, I had the shop change the fluid again since after furthur research they switched the gear oil according to the receipt. They had 80W90 in the rear instead of the front, and 75W140 in the front instead of the rear. Friction modifier added as well to Ford specs. The vibration is still present, but much less noticeable.

I am still thinking wheel bearings, but still looking for ideas.

Thanks,

 

I think you only need the friction modifier if you have ha LS differential right?

 

Please keep me up to date on what you find out. I am having the same problem as well. It has been freezing here so I haven't had a chance to crawl under mine yet. In other searches about this problem I have heard people say that the clutch packs need to be replaced. I have also read other posts that say , make sure your emergency brake cable is functioning properly. They say that the coupler on the cable malfunctions and gets stuck together and it causes it to apply the emergency brake a little bit which causes the vibration. Mine vibrates on acceleration from a dead stop when I turn either right or left. I also have a very annoying vibration that starts around 60 mph. I have new tires that are balanced properly so I know thats not the problem. Please keep me updated and I will do the same for you.

 

I have thought about the parking brake as I have had this problem in the Nissan I had years ago. I have not had a chance to check it yet either. It has been cold and raining here and it's goose hunting season, so these 4:30 wakeups are dragging on me. I will try to check the parking brake tomorrow and post up if I find anything.

Come to think of it, the PB has felt different in the last couple of days when I release it. Not as firm when I release the handle.

 

That is correct. I have the 3.73 LS.