Looking for the size of the bolts that are used to attach rockers or nerf-bars to the H3's frame.

Bought some aftermarket bars for my 2010 H3 and the bolts they supplied are just a hair to big... I can force them with a torque gun but I'm pretty sure I'll snap one, and that would be bad.....

 

i still dont speak metric very well so i dont remember sizes. there are about 746,387 sizes.
go to ace hdwe and try 3 that look close.
for each size there are 2 pitches like the old American course and fine.

oh, dont force anything
tom

ps im thinking they are 8 mm

head sizes also vary so buy a dozen or so sockets,

also the driver side front is impossible to get at,fwiw

 

The correct size is a 3/8"x16 English thread. You are probably trying to fit a M10x1.5 Metric which is only .0187" diameter larger, so that's why is seems close, but won't quite fit. I'd suggest you first chase the frame threads with a 3/8"x16 tap, to clean any rust, then use an 'anti seize' compound on the bolts, for easy removal if you ever choose to. Also, be sure to use lock washers.

 

That is exactly it ! Thanks... the packing list that came with the bars show M10 which I thought was odd on a North American truck

Much obliged !

 

youll see its metric, been there did that,,,at ace

 

mine weren't metric.....

 

funny, i pulled a bolt,took it in the store, lined the threads up with a bolt till i found one where the threads fell neatly into the others checked them both with a nut, same nut. heads were 14 mm on one 15 on other. i used some old,some new when i mounted the lowering brackets. all worked same.

i had to loosen the brake cable, that bolt was 10 mm.
guess i got a rare metric version.
i know detroit talked about going metric 25 yrs ago but i didnt think they ever would.

now you guys have confirmed it,,no metric in h3,,wow

 

Not true drtom, just to make things more inconvenient for us to work on our Hummers, there's actually a mixture of metric and English fasteners used for the overall assembly. Some components that originate from China, Spain, etc. etc., will have metric fasteners. Other components made here in the states (ya, believe it or not), will be English. Good reason to have both kinds of sockets/wrenches in your tool box.

 

Definitely 3/8"x16 ... picked up a bunch, mounted the nerf bars. And yes, that front drivers side was a pain.. had to notch out the bracket to get it to fit properly.

 

just like 3/8 is almost but not quite 10 mm.

3/8 will go in nice and ez because its smaller but will on a long run bind up since the pitch is wrong. at least you shouldnt need a lock washer,,un less it dont bind up!

i drove into town with a spare h3 bolt and a 3/8 bolt. i handed them to the mgr of ace hdwe and asked him to identifty them. he did. the h3 is 10mm metric.

DONT TRY TO FOOL THE OLD FOOLS!!! WEVE STRUGGLED WITH MIXED BOLTS B4 URE DAD TOOK OFF YOUR TRAINING WHEELS !!!

so you might get away with the wrong size but if u strip them you may need to retap the holes??

good luck, when in doubt take the bolt to the store and test them,,dont guess

tom

ps, there MIGHT be some english bolts but it seems unlikely if the frame is tapped for metric!, which it iz!