Rear suspension bolt size question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

softballnrd27 · 01-27-2009, 01:07 PM

I got the leaf spring hangers for the rear 2wd conversion, now I need to bolt them on. I got 7/16"-20 grade 8 bolts, is that enough or should I have gone 1/2"? I eventually plan to take it to the strip and abuse it.

James McClure · 01-27-2009, 04:14 PM

The only limitation as to bolt size is the size of the hole in the spring end bushing. If the hole measures .5" use that size bolt. I think they are .5" but wouldn't swear to it. Grade 8 is more than enough. Springs or hangers will break before a grade 8 bolt will. jim

softballnrd27 · 01-27-2009, 04:22 PM

I am not changing the spring eye bolts. I am converting a 4wd to 2wd and need to bolt the 2wd brackets to the frame. Sorry I didn't clarify

454HO · 01-27-2009, 05:54 PM

If I recall correctly, the rivets are an odd size. A 3/8" bolt will be too loose, and a 7/16" will not fit. So on mine I used a step drill bit to enlarge the holes to 7/16". I used grade 8 bolts, but then I used nuts with nylon lock inserts which are grade 5.

softballnrd27 · 01-27-2009, 09:28 PM

I've got 7/16 fine thread grade 8 bolts, lock washers, regular nuts and some red threadlocker to put on them as well. They should stay on there.

01-27-2009, 01:07 PM	#1
softballnrd27 Always a work in progress Join Date: Jun 2007 Location: Harker Heights, TX Posts: 1,599	Rear suspension bolt size question I got the leaf spring hangers for the rear 2wd conversion, now I need to bolt them on. I got 7/16"-20 grade 8 bolts, is that enough or should I have gone 1/2"? I eventually plan to take it to the strip and abuse it. __________________ USMC Retired Never trust a man who can't laugh at his own fart! 2010 Silverado Crew Cab 73 SWB 5.3/4l80e Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=695168

01-27-2009, 04:14 PM	#2
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: Rear suspension bolt size question The only limitation as to bolt size is the size of the hole in the spring end bushing. If the hole measures .5" use that size bolt. I think they are .5" but wouldn't swear to it. Grade 8 is more than enough. Springs or hangers will break before a grade 8 bolt will. jim __________________ 1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.

01-27-2009, 04:22 PM	#3
softballnrd27 Always a work in progress Join Date: Jun 2007 Location: Harker Heights, TX Posts: 1,599	Re: Rear suspension bolt size question I am not changing the spring eye bolts. I am converting a 4wd to 2wd and need to bolt the 2wd brackets to the frame. Sorry I didn't clarify __________________ USMC Retired Never trust a man who can't laugh at his own fart! 2010 Silverado Crew Cab 73 SWB 5.3/4l80e Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=695168 Last edited by softballnrd27; 01-27-2009 at 04:23 PM.

01-27-2009, 05:54 PM	#4
454HO Registered User Join Date: Apr 2005 Location: Austin, TX Posts: 1,223	Re: Rear suspension bolt size question If I recall correctly, the rivets are an odd size. A 3/8" bolt will be too loose, and a 7/16" will not fit. So on mine I used a step drill bit to enlarge the holes to 7/16". I used grade 8 bolts, but then I used nuts with nylon lock inserts which are grade 5. __________________ - Greg

01-27-2009, 09:28 PM	#5
softballnrd27 Always a work in progress Join Date: Jun 2007 Location: Harker Heights, TX Posts: 1,599	Re: Rear suspension bolt size question I've got 7/16 fine thread grade 8 bolts, lock washers, regular nuts and some red threadlocker to put on them as well. They should stay on there. __________________ USMC Retired Never trust a man who can't laugh at his own fart! 2010 Silverado Crew Cab 73 SWB 5.3/4l80e Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=695168

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