Cliff Notes: Swapped diff fluid, getting a slight grinding noise when doing sharp turns and figure 8's. Is this noise what is described as "diff chatter"?

Over the winter and for a few months before, my car was stored in the garage. The winter part goes without saying, but I had lost my license for 6 months as well. During this time, I swapped my tranny and rear diff fluid. Tranny got Amsoil ATF, diff got Severe Gear 75-90.

When I got my license back, I took the car out to a large local parking lot and proceeded to do some figure 8's and circles as I was told this would get the fluid properly drawn up. I immediately noticed what I would describe as a slight grinding noise, and even a slight "loose" sound. By loose, I mean it sounds as if something in the rear diff area is moving around. The kind of noise you would get from your suspension if something wasn't tight. Kind of a clunking sound, but not nearly as loud as suspension would be and less pronounced than the slight grind noise I'm hearing.

Of course I had researched before buying, and was told that although the Severe Gear comes with the limited slip additive already in it, its possible that some of the Slip Lock additive might need to be added to quiet things down. I do have a small bottle of it.

The diff is a Cartek built 4.10 for what its worth. Does anybody with experience here believe that the noise(s) I'm hearing are normal diff chatter and that I should be able to quiet things down with the additive or might it be something else?

Thanks

 

Hmmmm.........did you read their web page on the product during your research?

From the Amsoil website:

"AMSOIL SEVERE GEAR® is compatible with most limited slip differentials. If limited slip differential chatter occurs, add AMSOIL Slip-Lock™ friction modifier additive."


https://www.amsoil.com/storefront/svg.aspx?zo=1409802

 

I did, but I was told by I believe Subdriver, our forum Amsoil man, that the Severe Gear already has some limited slip in it to begin with. Then if you experience some chatter to add some of the additive until it quiets down making sure not to add too much and make it too slippery.

What I'm wondering is if these sounds I'm hearing are normal diff chatter noises.

 

I'm confused. You did not have any chatter before changing the fluid. After changing the fluid, you have chatter (and Amsoil clearly states what to do if this occurs), and you think it might be normal?

 

I Didnt have to add any additive to mine, but my buddy did on his for some reason - follow what lucky and amsoil is saying to do

 

What I'm asking is can the noises that I'm describing be classified as diff chatter? I don't know what diff chatter sounds like, so I'm wondering if it sounds like a slight grinding noise. I want to make sure its just that and not something more severe.

What I meant by normal diff chatter was could what I'm hearing be classified as run of the mill diff chatter.

Sorry for the confusion.

 

I understand your concern, and you are smart to ask the question, but the question still remains: did you have any noise before changing the fluid to Amsoil?

 

Well, none that I noticed, but I had never before taken the car to an empty parking lot for the sole purpose of driving in tight figure 8's and close to full-lock circles. Obviously now that I have the noise I'm going to add some of the additive, but again my main concern was that what I was hearing was just diff chatter and nothing more.

After I add it in I'll post up the results.

 

Good, don't jump to conclusions just yet. Tell us what you hear after adding the FM