Exact Motorsports RCA Bolt Failure!!!
02-14-09, 11:55 PM
#46
One bolt does allow for a pass-through. I bought a slightly longer 12.9 class bolts from Hilco because they didn't have exact length.
reference: https://www.clublexus.com/forums/gs-...2-9-grade.html
reference: https://www.clublexus.com/forums/gs-...2-9-grade.html
02-15-09, 01:56 PM
#47
guys, exact is already doing all the necessary measure and also recalling customers to check on their rca bolts. they are also doing a lot of testing to find out and address the issues. we don't need more speculations here. unless they come back here and post up information (give them a bit time) or the person with problem sending them the failed bolt for analysis, let's be patience. more speculations here won't help anything
02-15-09, 03:53 PM
#48
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The bolts are grade 12.9, these are the best grade bolts in the market, the torque spec is 120 ft lb. Make sure don't over torque them, you may snap them, but do not under torque also. Make sure torque them evenly, torque both bolts at 75 lb first, then torque them at 120 lb to tighten them. Do not torque one side all the way, then the other!
I wish EXACT would have posted what you just said.
All they did was post the above message....and said nothing about testing or calling customers....or trying to find out what went wrong.
The only reason for the speculation was because EXACT wasn't providing any form of communication....if they did, this thread would not have gone in this direction.
03-01-09, 08:58 AM
#55
The ae86 guys use an rca with the 12.9 grade bolts and there have been a number of failures. Mainly due to the fact that people would be installing them in thier garage using just an alen wrench and not getting them torqued down properly. The 12.9 grades are really stiff bolts, they can take alot of torque, but if you put any kind of bending load on them, and they snap right off.
So when you install those things, make sure the surfaces are clean and flat, and always make sure you get them to the right torque. I wouldnt be worried about 120lbs being too much.
So when you install those things, make sure the surfaces are clean and flat, and always make sure you get them to the right torque. I wouldnt be worried about 120lbs being too much.
05-28-09, 02:46 PM
#57
The bolts are grade 12.9, these are the best grade bolts in the market, the torque spec is 120 ft lb. Make sure don't over torque them, you may snap them, but do not under torque also. Make sure torque them evenly, torque both bolts at 75 lb first, then torque them at 120 lb to tighten them. Do not torque one side all the way, then the other!
Last edited by macd7919; 05-28-09 at 02:53 PM.
06-22-09, 01:57 PM
#59
Don't try this at home kids
I paid way too much money (near $7 ea) for grade 12.9 M12x60mmx1.25 thd Socket Head Cap Screws. For someone who want's a joint at factory spec, a GR 10.9 is available for 5x less cost @ King Bolt. I'm just paranoid. Since these fasteners have a black oxide finish, I'm also glad I live in SoCal where steel corrosion is moderate (I don't live at the beach). Other suggestions:
1) use a AN960-816 (1/2") washer under the head since you're unlikely to find a flared head bolt like stock. Grade 8, should be fine.
2) torque them to 90-100 ft-lbs. Under static loading, the GR 12.9 bolts should survive 120 ft-lbs, but once shock loads enter the mix, they are susceptible to fracture due to the high hardness. There's no point in running them to the ragged edge (to yield) anyhow since you should be using Loctite.
3) Use medium thread locking fluid. In addition to preventing bolt backout, it also lubricates the threads to limit the scatter on a torque vs preload curve.
Just my opinion.
1) use a AN960-816 (1/2") washer under the head since you're unlikely to find a flared head bolt like stock. Grade 8, should be fine.
2) torque them to 90-100 ft-lbs. Under static loading, the GR 12.9 bolts should survive 120 ft-lbs, but once shock loads enter the mix, they are susceptible to fracture due to the high hardness. There's no point in running them to the ragged edge (to yield) anyhow since you should be using Loctite.
3) Use medium thread locking fluid. In addition to preventing bolt backout, it also lubricates the threads to limit the scatter on a torque vs preload curve.
Just my opinion.
Last edited by cone_killr; 06-22-09 at 02:09 PM.