Chief buggy

[Bebop]

Are we talking about having non-thread 'shank' between the link tabs rather than a bolt that has a shorter shank and then threads through one tab?

Yes

 

[Wisconsinite]

If it is torqued properly, I don't think it is that big of a concern. A bolted joint should be relying on clamp load vs. bolt shear strength.

 

[JohnnyJ]

Are we talking about having non-thread 'shank' between the link tabs rather than a bolt that has a shorter shank and then threads through one tab?

yeah. I was just thinking I broke 2x. Left and right side rear upper link bolt, similar maneuver of sliding back off an obstacle with all weight hitting that side. The bolt I used was "right length", but the transition from shoulder to thread was right where the rod end to spacer met. First time I thought a fluke, second time I turned on the brain and went with right shoulder length and cut off thread as needed.

If it is torqued properly, I don't think it is that big of a concern. A bolted joint should be relying on clamp load vs. bolt shear strength.

In my second fail, I had torqued bolt before the trip. Maybe it was already hurt, but since then I've always paid attention to where the shoulder lands and have no problems since. Maybe belt and suspenders.

 

[chaplinfj60]

I can relate to the wrong length bolt being used. It wares out the hole real quick. Live and learn.

 

[pennsylvaniaboy]

I will say the cost diff from 7/8x3/4 is substantial to 1.25....the special misalignment spacers needed to get the 2" mount with are like $17 ea for the 1.25 heims.

 

[white-rhino]

If it is torqued properly, I don't think it is that big of a concern. A bolted joint should be relying on clamp load vs. bolt shear strength.

It does make a difference. Especially if it is a heim joint with alignment spacers. I’ll dig up some pics.

 

[Sluggy]

I run 7/8 uppers and 1.5 tube on my rear with no issues.

 

[RustyC]

 

[Bebop]

If it is torqued properly, I don't think it is that big of a concern. A bolted joint should be relying on clamp load vs. bolt shear strength.

Real life experience from every single racer out there says different though.

AN bolts with specific grip length are there for a reason.

 

[pennsylvaniaboy]

yup...this is perfect for 7/8x3/4 heims.... the issue is the 1.25" heims are usually paired with 2-5/8 brackets. Hulse engineering brackets are setup for 2" width to allow you to get the bolts out and run an engine skid that attaches to the belly.

thus you end up using kartek spacers
17-4 Stainless Steel Misalignment Spacer For 1" Heim Or Uniball For 3/4" Bolt 2" Stack Height - Kartek Off-Road

 

[white-rhino]

This is my upper frame end joint. Typical 3/4-9/16 joint with spacers that would fit in place of a 2-5/8 wide joint with 9/16 bolt. You can see where over time the bolt fatigued that (IMO) was caused by two separate issues.
1) the failure is right where the bolt shank meets the thread, which has a stress riser point.
2) the 3 piece heim/spacers allows a "flex" point between the heim and spacer, which in this case lined up almost perfectly with the end of the bolt shank.

Note the fatigue marks in the bolt.

I swapped these out for TMR full body joints and went full length with the shanks. This is one of the reasons I like Johnny Joints vs 3 pcs heims/spacers.

RE torqueing the bolts, sure that's important. But with the constant push - pull of the suspension on a joint, you can see where the fatigue lines were in one direction and simply failed over time.

 

[Bebop]

This is my upper frame end joint. Typical 3/4-9/16 joint with spacers that would fit in place of a 2-5/8 wide joint with 9/16 bolt. You can see where over time the bolt fatigued that (IMO) was caused by two separate issues.
1) the failure is right where the bolt shank meets the thread, which has a stress riser point.
2) the 3 piece heim/spacers allows a "flex" point between the heim and spacer, which in this case lined up almost perfectly with the end of the bolt shank.

Note the fatigue marks in the bolt.

I swapped these out for TMR full body joints and went full length with the shanks. This is one of the reasons I like Johnny Joints vs 3 pcs heims/spacers.

RE torqueing the bolts, sure that's important. But with the constant push - pull of the suspension on a joint, you can see where the fatigue lines were in one direction and simply failed over time.

Trophy trucks use 3 piece heim/spacers and 3/4 hardware.
If a 6000+lbs monster rolling at 100+mph in 3ft woops is using those, I don't thunk we need anything bigger.

They also use a lot higher grade hardware than grade 8 and torque them to very high numbers

 

[white-rhino]

Trophy trucks use 3 piece heim/spacers and 3/4 hardware.
If a 6000+lbs monster rolling at 100+mph in 3ft woops is using those, I don't thunk we need anything bigger.

They also use a lot higher grade hardware than grade 8 and torque them to very high numbers

Sure. Just sharing my experiences. Most U4 racers do the same thing. Was mine loose? Quite possible. This happened about 2 weeks after I bought the buggy. I can honestly say I never checked them before this happened. Do I want it to fail again? Nope.

And for conversation sake, the cross section of a 9/16 bolt is .249 sq in vs a 3/4 bolt @ .442 sq in, resulting in 77% greater cross section.

 

[Weasel]

9/16 is too small and it's a stupid bolt size. No one carries them anywhere anymore or they are tougher to find. At least go 5/8".

And I agree bolts should be torqued but also agree that having the correct grip length is just as important.


I've also noticed the width of alot of these joints, most are 2.625". Wish the were narrower options, not always needed.

 

[white-rhino]

^^^^ agreed but back in the day it was the norm.

 

[Richard Hulse]

Glad you are liking the chassis! Completely had forgot about this forum till I had a customer tell me about your build thread, so decided to make an account. Please feel free to keep hitting me up with questions or advice, IG or FB messenger is usually much quicker than me remembering to check the forums though.

 

[pennsylvaniaboy]

So some updates. Orders some parts from Barnes4wd and got my engine and drivetrain mounts all tacked in.

 

['84 Bronco II]

Can you get the bushing closer to the block to reduce the chance of cracking the block?

 

[pennsylvaniaboy]

I so on the drivers side i can’t. With the filler neck and oil outlet. A passenger maybe. But honesty just are hard mounting these and have no issues

 

[Sterlingfire]

Nice! Making good progress!

 

[Bebop]

Can you get the bushing closer to the block to reduce the chance of cracking the block?

Factory bushing is usually pretty far away from the block, isn't it ?

 

['84 Bronco II]

Factory bushing is usually pretty far away from the block, isn't it ?

I honestly am not familiar with factory LS applications, so I have no idea. The LS does have 4 mounting holes in the block, so maybe it's okay. Windsor blocks only have two mounting holes, and the factory mounts are directly under the block.

His driver side mount just made me uncomfortable, but it isn't ridiculous. I just figured now would be the time to make any changes.

 

[Bebop]

Gotcha. Always interesting to see what kind of failures are pretty common.

Some aluminum LS engines even have 6 mounting bosses per side.

 

[pennsylvaniaboy]

Gotcha. Always interesting to see what kind of failures are pretty common.

Some aluminum LS engines even have 6 mounting bosses per side.

I dont for see this being a failure. I guess I could tie in more bosses..

 

[JR4X]

I dont for see this being a failure. I guess I could tie in more bosses..

I think what you have is fine for a crawler. Might be worth a revisit if you were going to be jumping it.

 

[pennsylvaniaboy]

Well a little update. Had some time over thanksgiving to get after it. I got my link mounts all mocked up on the frame and axles. And got the artec steering arms welded up. I know these are controversial but used them before and had success. I think pre/post heat is key. I also add an extra plate to the outside so it sandwiches the knuckle.

 

[pennsylvaniaboy]

Also the front lower link is notched into the center section and will tie into the tube. Also made a mini truss

 

[94toytruck]

Me and a few friends have been running lower link mounts like that for a awhile now with no issues. We haven't notched into the cast, just fit the bracket and burned in and wrapped in a welding blanket.

 

[white-rhino]

Methinks you are really gonna like this over the K body.

 

[pennsylvaniaboy]

Methinks you are really gonna like this over the K body.

On no doubt. I love the truggy. It’s a beast, usually has 3-4 people in it. It’s the group pack mule, and tow truck. But I have reached it’s limits on trails and want to try some more challenging stuff (balderdash)