[DEAFM3]

So my front differential bolt snapped which caused my rear differential to thump. My differential mounts are like in brand new condition. It barely have over 3k miles since the install.

Even my bolt was 10.9 upgrade, it will snap! PLEASE INSPECT every time you are under the car!!!!

I have to buy a front differential bolt and differential fluid (redline 75w140). Also I recently acquired 235/40/18 bridgestone rear tires.

EDIT- front mount was bad/half assed pressed.

[white-hot]

They generally break due to the bushing being bad and allowing excess movement of the diff under load. Might want to change that out as well.

[DEAFM3]

Originally Posted by white-hot

They generally break due to the bushing being bad and allowing excess movement of the diff under load. Might want to change that out as well.

I am pretty sure it broke under load once the supercharger were installed and in addition of lightweight flywheel did hurt it. I am running about 16lbs flywheel so its hard to drive smooth and not letting the rpm drop too low.

[white-hot]

Others have run high HP and not snapped the grade 10.9 bolt. Just saying, I would check it prior to popping another bolt in there or you may be doing it all again.

[DEAFM3]

Not the best pictures but this will work. You be the judge to the condition of mounts. Let me know If i miss something.

[Jrrrrrrr]

Originally Posted by DEAFM3

Not the best pictures but this will work. You be the judge to the condition of mounts. Let me know If i miss something.

They appear fine in your pics. With the bolts removed from each bushing, can you induce flex easily with a pry device? Do you see cracks in the rubber when they finally do flex? If you can flex the bushings with a flathead with little effort, the diff bolts can obviously flex around that much easier.

[DEAFM3]

Tomorrow, I will inspect the bushings closely when the diff is out of the way. I also will test it.

I am really having some trouble taking off my remus exhaust. Just 2 freaking hanger. I don't even if it is safe to use PB blaster on rubber. Also its somewhat tight space.

[white-hot]

I do not see a pic of the front diff mount where you removed the bolt from, however the 4 subframe bushings appear to be PowerFlex Purples, a very popular poly bushing. The 2 rear diff mounts, well, you can not really see dry rot or cracking in photos. You will just have to take a good look at them and the front.

Bottom line, most of the time when that bolt breaks it is due to bad bushings. There are other causes, like the bolt backed out for example. If the PO changed out the subframe bushings he might have done the diff bushings as well. My point was you need to be sure before buttoning it all back up. I promise there are guys on here that run BIG HP numbers, so that alone is not the only possible cause.

[DEAFM3]

Originally Posted by white-hot

I do not see a pic of the front diff mount where you removed the bolt from, however the 4 subframe bushings appear to be PowerFlex Purples, a very popular poly bushing. The 2 rear diff mounts, well, you can not really see dry rot or cracking in photos. You will just have to take a good look at them and the front.

Bottom line, most of the time when that bolt breaks it is due to bad bushings. There are other causes, like the bolt backed out for example. If the PO changed out the subframe bushings he might have done the diff bushings as well. My point was you need to be sure before buttoning it all back up. I promise there are guys on here that run BIG HP numbers, so that alone is not the only possible cause.

Great info! I didnt realize that!

From what I saw, the front mount looks new. the bolt just snapped.

And I accidentally deleted my front diff mount where the bolt goes in when I was trying to upload. I pressed the wrong button.

[DEAFM3]

I talked with previous owner, he replaced all the bushings down there last year. Subframe and front diff mount. Thats why it looks new.