I am currently running the FBM 8.8 differential setup and have been for a couple years for around 1500 miles or so. During the build, I decided to keep the stock diff mounts and add the collars to stiffen them up a bit. The car has been at 600whp and only street driven during these past couple years. Over the past couple weeks, I noticed a small amount of vibration during WOT pulls but figured it was the drag radials gripping until today happened. During a pull, it felt like the trans/rear end exploded right after I felt that vibration. After investigating the noise, I saw that the rear left axle bolts were digging into the lower subframe. The diff mounts must have let go and allowed the rear end to sag which caused this. LUCKILY, the axle looks okay, and the subframe took the torture of bolt beatings. The bushings probably started failing a few months ago and finally let go today.

In the first pic you will see how its sitting and what it did to the subframe. Those axles have pretty strong ass bolts! The photo doesn't do it justice. There is a pretty huge chunk eaten off the subframe.




In this photo, you can see the slight amount of sag on the backside. The front side was worse.




So in the end, I am now going to upgrade to the Hasport mounts and get back on the road. I'm thankful that nothing else broke. I swore it was tranny #3 in the dump, whew!

 

Wow that sucks

 

one of the first things i did was upgrade the diff mounts hasport 95A

 

Wow! You post this the day after I bought new aftermarket mounts. Could have been worse, right?!?

 

good thing you were able to catch it before anything worse happen!