Quick Performance 9" Fitment Issue (Brake Bracket Bolts)
04-08-2012, 02:44 PM
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Quick Performance 9" Fitment Issue (Brake Bracket Bolts) After seeing that people who own a QP rear on here have slight issues with fitment of parts, I decided to check everything prior to painting my rear end with POR-15. Low and behold, I've got a slight issue with the bolt holes for the brake brackets.
QP's hardware kit that came with the rear end came with 10 fine thread studs which I'm assume are for the center section and 8 fine thread allen head bolts that appear to be for the brake brackets. There's also a full set of locking washers and nuts for all of them.
Using the bolts, inserting them so that the bolt head is on the rear end's side causes the bolt to be crooked and not enter the bolt hole properly, which causes it to eventually jam up against the side of the rear before extending far enough to get the brake bracket on. Here's a pic:
Likewise, putting the bolt on the brake bracket side doesn't work because the nut is too tall and doesn't line up properly with the hole on the rear end. As a solution, I ground down the bolt until the bolt could sit parallel to the axles:
Has anybody else encountered this problem? I'm worried about modifying the bolts and changing the tensile strength of the bolt in the event I want road race the car.
Any help would be greatly appreciated. This is the last hurdle before painting the rear and assembling.
Thanks in advance.
QP's hardware kit that came with the rear end came with 10 fine thread studs which I'm assume are for the center section and 8 fine thread allen head bolts that appear to be for the brake brackets. There's also a full set of locking washers and nuts for all of them.
Using the bolts, inserting them so that the bolt head is on the rear end's side causes the bolt to be crooked and not enter the bolt hole properly, which causes it to eventually jam up against the side of the rear before extending far enough to get the brake bracket on. Here's a pic:
Likewise, putting the bolt on the brake bracket side doesn't work because the nut is too tall and doesn't line up properly with the hole on the rear end. As a solution, I ground down the bolt until the bolt could sit parallel to the axles:
Has anybody else encountered this problem? I'm worried about modifying the bolts and changing the tensile strength of the bolt in the event I want road race the car.
Any help would be greatly appreciated. This is the last hurdle before painting the rear and assembling.
Thanks in advance.
04-08-2012, 04:05 PM
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Hmm. After skimming through Hiltsy855's amazing 8.8 build thread, it appears grinding down the bolts is more common than I thought:
I'm thinking I should probably get a hold of some stronger ARP bolts with a hex head that's larger.
I'm thinking I should probably get a hold of some stronger ARP bolts with a hex head that's larger.
04-08-2012, 08:55 PM
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You sir, are the man of the hour. Thank you!!!! Here's a link for future reference:
http://www.moserengineering.com/othe...-bolt-kit.html
http://www.moserengineering.com/othe...-bolt-kit.html
04-08-2012, 09:05 PM
#6
Proof load for a 3/8-16NC grade 8 bolt is about 9300# link. Making a wild assumption that grinding one corner off the bolt weakens it 50% (there is no way it affects it that much) you still have 18,600# of clamping force holding the axle in the housing. Unless you're pulling 4 g's on the skid-pad I think that's sufficient. Also consider when road racing the outside tire is the one with the greatest load and it's being pushed into the housing so there is no load on the bolts. Just use good bolts, grind the heads to fit, and call it a day. 
