Long arm ( radius arm style ) build

[CAVE]

Finished my long arm build today. You can check out the article on my Blog... Yeah I know, blogs are for girls.

http://1997jeepcherokee.blogspot.com/

Oh, one other thing. Do cartridge style joints (i.e. flex joints) normally make noise or is that what happens when they get worn. I haven't ever used them before and didn't know how tight to put them together. I tightened them up pretty tight, but with all the grease I used to get them together, they may go a little tighter. They just make a little clank on harder bumps like you would hear from a worn heim joint.

Enjoy

CAVE

 

[old_man]

Nice fabricating.

 

[madmax]

thats looks really clean

mad props

 

[RCP Phx]

Damn,I knew I should have put a Patent on my work!:doh:
A+ for accomplishment!
D- for originality!

 

[CAVE]

Yeah, those bracket designs are straight up copied. Whas it your build that it came from? With all the people out there fabricating suspension, it would be quite a feat to come up with something new. Sure its easy to change someone elses design, but to truly come up with something new... i don't know if it could be done in a long arm setup. Anyways, thanks for coming up with a good style arm bracket for me to copy.

 

[rehab]

hey those look a lot like my upper arms!

they look good but why didn't you turn the angle iron up the other way on the cross member so you had more clearance?

like stated before: good work, but originality lacks. at least you built them yourself and didn't shell out 700-900 bucks for the other stuff thats out there.

 

[old_man]

Hey those look very much like the arms I built 6 years ago and published the pictures of. Who copied who???:laugh:

 

[Mosephus]

I like your pics, very informative.

 

[offroadman83]

very nice blog/writeup. Makes me wanna go out and build the same. ----------Kyle

 

[pdharrin]

It looks like there are only the four stock nutsert bolts and 4 additional bolts securing the crossmember- is this really enough? It seems that every other other setup I have seen uses at least 10 bolts.

 

[CAVE]

You are correct. I only have 4 bolts per side. Here is a thought though. How many bolts hold your suspension in place.... 2... sure they are 9/16", but there are still only two. Now one of the engineer types can run the numbers and tell us the different forces on the lower control arm bolts and the crossmember bolts and decide if 8 vs 2 is really adequate. I'm going to go out on a limb and say that the control arm bolts will fail first. Think of it realistically, the crossmember would have to rip off of the frame and probably have to pull the bolts through the steel. I don't think that would ever happen. If it did I would probably have worse problems than crossmember bolts. Anyone disagrree? To go back to my first question, how much noise do those flex joints make? Should they make any?

 

[rehab]

flex joints make a lot of noise when they wear out. just keep them tight and keep all the mud and crap out of them.

 

[vetteboy]

Here is a thought though. How many bolts hold your suspension in place.... 2... sure they are 9/16", but there are still only two.

I count 4 (you forgot the uppers), in double shear, bolted to areas designed to take the tensile and compressive forces transmitted by the arms rather than thin single-layer sheetmetal.

That being said, with the frame reinforcements you have, you're probably fine. I would have gusseted the center crossmember piece to the angle iron sides to increase the weld area and to help it resist bending but other than that it looks like a good execution of the typical longarm thing.

 

[XJ_ranger]

You are correct. I only have 4 bolts per side. Here is a thought though. How many bolts hold your suspension in place.... 2... sure they are 9/16", but there are still only two. Now one of the engineer types can run the numbers and tell us the different forces on the lower control arm bolts and the crossmember bolts and decide if 8 vs 2 is really adequate. I'm going to go out on a limb and say that the control arm bolts will fail first. Think of it realistically, the crossmember would have to rip off of the frame and probably have to pull the bolts through the steel. I don't think that would ever happen. If it did I would probably have worse problems than crossmember bolts. Anyone disagrree? To go back to my first question, how much noise do those flex joints make? Should they make any?

yes, but youve taken a 4 arm, 4 frame side bolt situation, and bolted that to your crossmember with only 2 bolts...

and that crossmember also holds the engine torque, tranny and t-case weight and torque, and takes hits from being the limit of your breakover angle...

id personally would want that to be as rigid and bolted in as possible...

 

[CAVE]

Good point. I am planning on beefing up the angle on the crossmember, but as far as the bolts... yeah may need more.. may not. Hopefully is doesn't break at speed and kill me. Anyways, I'll post updates if I have problems.

 

[XJ_ranger]

Good point. I am planning on beefing up the angle on the crossmember, but as far as the bolts... yeah may need more.. may not. Hopefully is doesn't break at speed and kill me. Anyways, I'll post updates if I have problems.

try and remember that your long arms locate your axle...

and your axle is what has your front brakes (approx 70% of braking power), steering, and suspention on it - and there are a lot more forces there than just the weight of the vehicle at rest...

 

[wheeling_4life]

hey could you send me the measue ment so i can do this for my xj and how big of a left do you have

 

[tealcherokee]

youd be surprised at how little it takes to hold the control arm mounts on the frame w/o having an issue. as far as breaking, its all rotational forces on the axle, and steering is all on the track bar

 

[old_man]

youd be surprised at how little it takes to hold the control arm mounts on the frame w/o having an issue. as far as breaking, its all rotational forces on the axle, and steering is all on the track bar

Its all rotational forces......care to rethink that a bit. You seem to forget the inertia of the vehicle that appears in shear front to rear.

 

[jpcherokeekid]

Looks nice, im hopping mine will turn out decent.