Heim joint size

TBItoy · Jun 22, 2016

Re: Re: Heim joint size

jccarter1 said:
I hate yall I guess I can break anything I have had problems with breaking bolts on my 7/8 upper link in when that happens it screws up the misalignement spacers and joint

Upper "link" so I'm assuming 3 link with one upper?

What size bolt?

I've seen 9/16 and 5/8 bolts fail, from the bolt getting loose due to bracket deformation, misalignment spacer crushing, or just plain ol not being tight begin with.

Hardly anyone torques their link bolts tight enough. A 3/4 bolt is supposed to be torqued to ~300lbf

TBItoy · Jun 22, 2016

Re: Re: Heim joint size

rpf500 said:
Are you saying 7/8 shank, 3/4 bore or vice versa?

Craig_c said:
Basically a 7/8 Heim with a 3/4 ball, so you have 3/4 through hole, a smaller ball than a normal 7/8 Heim, which puts more metal holding the ball in place.

This.

Red97 · Jun 22, 2016

You fellas running the cone spacers for the larger bolt size, or the high misalignment with smaller bolt?

Sorry for the dumb questions, hard to find a thread without people say anything less than 1 1/4 will fail in short order

rpf500 · Jun 22, 2016

Red97 said:
You fellas running the cone spacers for the larger bolt size, or the high misalignment with smaller bolt?

Sorry for the dumb questions, hard to find a thread without people say anything less than 1 1/4 will fail in short order

I run high misalignment spacers with no issues.

TBItoy · Jun 22, 2016

Re:

I've ran em both ways, but on the Gremlin I used the "misalignment washers" that keep full bolt size and welded them to my link tabs. That makes it much easier to assemble, and reinforces the tab hole. It's got 3/4x3/4 heims with 3/4 bolts fully shank engaged in the tabs then excess threads cut off. I red loctited and torqued to everything my impact would do at 120psi then put a jack handle on a 1" breaker bar and put out all I could on them with another breaker bar and pipe against the shop floor...

I don't have a torque wrench that reads over 200...

I also built the links with the heims fully threaded in

Craig_c · Jun 22, 2016

My uppers with 3/4-7/8 have normal misalignment spacers welded to the link tabs, and use a 3/4 bolt.

My 1 1/4 lowers use high misalignment spacers which take the bolt size down to 3/4. I run L9 fine thread bolts, which like mentioned earler torque to a very high number....just can't remember what that was. Several hundred ft lbs

jccarter1 · Jun 23, 2016

5/8 bolt plenty tight seared off and it was grade 8 and 4 link but only on driver side

tonybolton · Jun 23, 2016

jccarter1 said:
5/8 bolt plenty tight seared off and it was grade 8 and 4 link but only on driver side

I've had a 5/8 upper link bolt break, but I think it was mostly due to being the wrong size(length).

The bolt that broke seems it was to short, meaning that where the shank of the bolt ended and threads began, were right in the middle of the heim joint. So the most force / stress was being transferred into the weakest part of the bolt.

I replaced both with same grade 8 bolt, but used a longer bolt that let the shank of the bolt continue through the heim joint and partially into the tab on the other side. This should keep the meat of the bolt doing most of the work.

jccarter1 · Jun 23, 2016

Yea that is what I thought on the first one that broke bc it broke both sides so I figured it broke thread side first then the shank side but the second one broke shank and caught it in time

natedawgxj · Jun 23, 2016

I ordered mine without high misalignment spacers instead I got stainless spacers to use 3/4 bolt because i knew a 5/8 wouldn't hold up with my driving style.

June dog · Jun 23, 2016

I'm running 7/8 helms with 3/4 misalignment spacers on upper and lower links for over 4yrs now. I've never had any issues or had to replace anything yet. Guess I do t beat on mine as bad as everyone else. :dunno:

TBItoy · Jun 23, 2016

jccarter1 said:
5/8 bolt plenty tight seared off and it was grade 8 and 4 link but only on driver side

tonybolton said:
I've had a 5/8 upper link bolt break, but I think it was mostly due to being the wrong size(length).

The bolt that broke seems it was to short, meaning that where the shank of the bolt ended and threads began, were right in the middle of the heim joint. So the most force / stress was being transferred into the weakest part of the bolt.

I replaced both with same grade 8 bolt, but used a longer bolt that let the shank of the bolt continue through the heim joint and partially into the tab on the other side. This should keep the meat of the bolt doing most of the work.

Yep that's what I was afraid of and I went 3/4 . If the bolt is sized correctly for the application and stays tight, it shouldn't see shear forces like a pin. Problem is 5/8 bolts aren't strong enough to get enough torque in them to clamp everything solid, so they stretch, get loose, then you are depending on an already fatigued piece to act as a pin.

Good info.

guys run 1/2 and 9/16 bolts on jeeps, but most have bushings or flex joints so that takes a lot of the impact

Rjhoward32006 · Jun 23, 2016

My old three link samurai had 3/4" heims they got old but werent clanky and i beoke a bunch of them. And when your suspension comes apart and brakes other things, youd wish you would of had bigger. My new toyota buggy has i think 7/8 heims uppers and lowers. with 3/4" misalignments. Could have sworn they came from ruffstuff but hopefully not after reading this. Anyway they have held up great so far

toyota104 · Jun 23, 2016

I just ordered the 3 & 4 link kits from barnes 4wd. I got the 7/8" heim kits and they came with misalignment spacers for a 1/2'' bolt. After reading this I think I should drill out the holes on the brackets for a larger bolt and get different misalignment spacers to match.

natedawgxj · Jun 23, 2016

I would no doubt.

Beerj · Jun 26, 2016

What about using cone spacers? I understand thay don't reduce the bolt size.

617_Racing · Jun 27, 2016

Beerj said:
What about using cone spacers? I understand thay don't reduce the bolt size.

That's how the track bar was on my 3 link set up from RuffStuff. 7/8 x 3/4 with the cone spacer. 3/4" bolt fit through. Only problem I had was theirs made it too wide for the frame mount they provided with the kit. Nothing a flap wheel on the grinder couldn't fix though.

natedawgxj · Jun 27, 2016

617_Racing said:
That's how the track bar was on my 3 link set up from RuffStuff. 7/8 x 3/4 with the cone spacer. 3/4" bolt fit through. Only problem I had was theirs made it too wide for the frame mount they provided with the kit. Nothing a flap wheel on the grinder couldn't fix though.

Had the same problem with mine those stainless cones are a MFer to grind.

617_Racing · Jun 27, 2016

natedawgxj said:
Had the same problem with mine those stainless cones are a MFer to grind.

I don't think mine were stainless. They were super easy to grind down. But then again that was 2 or 3 years ago I think.. I'm reusing those heims on my buggy build for the engine cage so it'll act like a hood, just because I already have them.