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Bolt sizes / specs?

TA2Jeep

NAXJA Forum User
Location
661 - $o*Cal
Finally getting around to doing the lift on my '99 XJ and I'm wondering if anyone knows the bolt sizes / specs to replace the shock mount and leaf spring bolts. I'd rather just have new ones on deck and ready to go, rather than pulling them out (or having them break) and then having to go pick them up in the middle of the job..


Thanks!
 
i called the local jeep dealer when i did mine they had the bolt sizes in their computer and ordered them next day, had them for me by 8 on a saturday morning, and ordered them on noon friday, little more expensive than spending time at bolt supply stores, but worth it IMO, and the right grade of bolt, nut, etc etc.
 
Check out 5-90's site IIRC its kelleyswip.com
 
One thing about the Jackit hardware that concerns me, is that it says it's grade 8 fine thread, which would be standard sizes, and needs 40 lb ft of torque. The factory hardware is Metric...
 
factory rear upper shock bolts are 5/16-18 to the best of my knowledge, grade 8. Either a 5/16 or an 8mm will work as long as you get a good enough grade, and you want to use washers or a flanged head bolt, I'd go with washers. Expect the bolts to break off in the nuts... some years the nuts will easily come out with a punch, some they're very securely welded in place and will have to be drilled.

No such thing as grade 10 btw - you're probably thinking of metric 10.9 hardware, which is slightly different.

All leaf spring and LCA bolts can be replaced with M14x2.0 (ISO property class 10.9 or 12.9 ONLY!) bolts (120mm long), with flanged head, nuts should be all-metal locknuts (staked, flanged.) The rear leaf bolt that goes through the shackle and all LCA bolts can be replaced with a 9/16 grade 8 if you can't find anything else, you might have to bore the bushing sleeve out a tiny bit as this is 1/4 mm larger in diameter. The ones that go into a captive nut in the frame have to be replaced with metric as hubs said, since the nuts are metric and you really really don't want to jam one of those bolts in there...
 
Common SAE grades are SAE2 (uncommon,) SAE5, SAE8, and SAE L9 (rare!)

ISO property classes are a decimal number - 4.8, 9.8, 10.8, and 12.9 are common (I don't recall the specifics offhand, I'd have to look them up.)

Those are the primary mechanical grades - there are also ASTM grades, used in structural applications, and I do believe there's one or two ASTM grades that exceed SAE8 in relative strength (and possibly one exceeding SAE L9.)

Once you get into "superalloys" (like ARP,) all bets are off. SAE, ISO, and ASTM grades only apply to standard carbon steel fasteners - they don't even apply to CRES (Corrosion REsistant Steel, or "Stainless." Stainless is/was trademarked, CRES is not.)

I'm trying to assemble a listing of OEM fastener sizes and notes on my site in the Tech section - start at www.kelleyswip.com/tech.html, and go from there. If you find something I don't have, I'd appreciate the information!
 
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