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· Super Moderator, How-To Author, TOTM
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Discussion Starter · #1 ·
I got a Fleabay Diff Drop kit in the mail today and upon inspection I have a few questions. First about bolt grade. The factory bolts are unmarked. The kit has 8.8 Metric. I don't know what the torsional forces the Diff bolts see, but I wanna be sure since even US Grade 2 is 100x stronger than 8.8 or are 4 of them acceptable here. Second is about dimension of the bolts. All 4 are the same length at 5" Is this correct? I cannot see the rear bolts under truck as easily as the front ones in the driveway. The front length looks plausible by eye. The spacer is 1"
http://www.ebay.com/itm/Differential-Dr ... DW&vxp=mtr
 

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· Super Moderator, How-To Author, TOTM
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Discussion Starter · #2 ·
I realized I was looking at the wrong bolts and cannot see the head of bolt at all. They come down from the top. Thru a cup on the bracket by the looks of it up on front side by the looks of it. Still can't see back though. I gotta get it off ground to see.
 

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Discussion Starter · #7 ·
19trax95 said:
A metric grade 8.8 is about equivalent to a grade 5 standard bolt.
I find differently. A 10.9 bolt like the factory apparently is. It's way closer than a Grade 5 is to the 8.8 that came with kit with 8.8 being the weakest out of the 3. I just don't want the worst case scenario due to some goof not grading the bolts correctly for the application when they put this kit together.
https://www.boltdepot.com/fastener-info ... Chart.aspx
 

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An update on the kit. I have had it installed for the whole winter and about 6k miles. I have used 4WD many times in snow with no ill effects or noises.
 

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Just got to the bottom and realized it was from last year lol. Anyway the 8.8 is roughly a grade 5 for future use anyway. The metric bolt is also rated on a different scale which may be what threw you off. Where the Sae scale uses PSI while the metric uses MPa. The 8.8 comes in just below but almost to the grade 5 spec and the 10.9 is almost at up to the same as grade 8. Which is much tougher.
 

· Mmbr Extraordinaire, TOTM, SS-Guru, How-To-Author
2010 GMC All Terrain 4x4 5.3 LC9 211k mi
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I was just reading through this is thinking the same thing...that the different scales were the confusion maybe.

I have a converter on my phone which I have used since the school days and for work. I still have trouble envisioning things in metric like lengths and whatnot...and for some crazy reason the US Army's fleet of Tactical Vehicles were designed entirely in metric and used metric fasteners! I was constantly converting to figure out what was what when I worked there.

Here is a basic conversion multiplier:

1MPa = 1N/mm2 = 145 pounds/inch2
 

· Member Extraordinaire, How-To Author, TOTM
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This is why I love working on European aircraft. Everything is so simple, no miss matching of hardware, its all metric. Only thing I have to convert is NM to inLBs for our torque wrenches.
 
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