RPM Steering and Suspension

[Gruff]

5 hours ago, Crawl2Camp said:

Scratchy tests?  LOL
  



 

 

Lol, seems the alum scratches/gouges easier than the 4130 does. IDK, maybe just my perception.

 

Bottom line reason for my build was that it was more convenient for my guy to cut the arms to length & weld the bungs in instead of getting them made up by someone else. And we did use 4130. I kind of assumed we were comparing that with the 7075 but I guess it wasn't directly stated.

[AJK]

Holyshit,,, now that is some awesome data and information. I am not concerned with going to aluminum anymore after seeing this information. The only reason I would stay with steel is to make my own. I need to see was a piece of 4130 would cost and that will probably drive my decision.

 

Kevin, thank you my man for sharing all this information.

[AJK]

Ok added question regarding 3 link. Is there any concern with running the Evo bent upper arms as a 3 link? I hear that a bent  arm on a 3 links is not the best idea.

[Jdofmemi]

4 hours ago, AJK said:

Ok added question regarding 3 link. Is there any concern with running the Evo bent upper arms as a 3 link? I hear that a bent  arm on a 3 links is not the best idea.

I would not want a bent link for the only one. It is taking twice as much force, and with the bend it already has a place to bend more. 

 

As for the cost, I bought the steel for the 4 link rear for about $120 or so at Industrial Metal Supply. 

 

The weld in bungs are the other cost, about $22 each at GenRight. Maybe cheaper elsewhere, but they are in stock. https://genright.com/shop-by-vehicle/universal-diy/threaded-step-race-bungs-each-multiple-sizes/

[AJK]

17 minutes ago, Jdofmemi said:

I would not want a bent link for the only one. It is taking twice as much force, and with the bend it already has a place to bend more. 

 

As for the cost, I bought the steel for the 4 link rear for about $120 or so at Industrial Metal Supply. 

 

The weld in bungs are the other cost, about $22 each at GenRight. Maybe cheaper elsewhere, but they are in stock. https://genright.com/shop-by-vehicle/universal-diy/threaded-step-race-bungs-each-multiple-sizes/

Thanks Jerry!

[fiend]

On 2/28/2023 at 9:42 PM, Crawl2Camp said:

You guys that want to use steel, why not go to 4130? That’s a lot stronger than 1026 DOM and you can run a much thinner tube (less weight) and have higher strengths.  Best of both worlds, but you’re going to pay for it .   I’ve seen more than one company making custom chromoly links for people.  

I seem to recall chromoly needs to be heat treated after welding. ??

[Crawl2Camp]

On 3/1/2023 at 3:18 AM, Gruff said:

 

Lol, seems the alum scratches/gouges easier than the 4130 does. IDK, maybe just my perception.

 

Bottom line reason for my build was that it was more convenient for my guy to cut the arms to length & weld the bungs in instead of getting them made up by someone else. And we did use 4130. I kind of assumed we were comparing that with the 7075 but I guess it wasn't directly stated.

You can compare the surface hardness of a material to its ability to prevent deformation. (Like a gouge etc).  Again the 7075 will have higher hardness than 1026, but will not be as hard as 4130 can be tempered to.  Normalized 4130 tube seems to be anywhere from 63-75KSI so again comparable to 7075. The plus with 4130 is you can temper it to much higher yield strengths. 

So the only issue with 4130 is that when you increase the strength of steel by adding carbon, chromium and molybdenum, the material also become more prone to cracking.  The key to preventing this with 4130 is having an extremely clean weld by ensuring the material is clean (free of oil, rust etc.), shielding with the correct gas and very importantly that the proper electrode is used.  After welding you should do a post weld heat treatment of the link.  This will relieve stresses built up in the material from welding as well as hopefully pull out any free hydrogen that may have been introduced during welding that can cause hydrogen embrittlement if it was absorbed into the surface. (Which can cause cracking and failure) The good ol Hydrogen atom can pass through solids and causes major issues in industry.  Simple moisture in the air can cause problems, and I’ve seen it effects firsthand at work.

You can try to limit the hydrogen absorption by doing a pre heat followed by a post heat and wrap in a weld blanket. Uncontrolled quick cooling is an issue.  Your weld and HAZ will still be compromised and the weak area if not heat treated, and should be inspected for cracking regularly IMO.  Ideally these should be vacuum heat treated and then cooled at a controlled rate.  Prior to this you can clean them in an ultrasonic vapor degreaser.  Zero issues then.


I found that you can buy custom 4340 links that are heat treated at bent fab.  (I saw others on Pirate)  I didn't call to ask what exact heat treatment process they have  performed so yeah.. 
https://www.bentfabaz.com/hardcore-links-s/113.htm

 

[Crawl2Camp]

1 hour ago, fiend said:

I seem to recall chromoly needs to be heat treated after welding. ??

LOL. Get out of my head! 

[AJK]

8 hours ago, Crawl2Camp said:

You can compare the surface hardness of a material to its ability to prevent deformation. (Like a gouge etc).  Again the 7075 will have higher hardness than 1026, but will not be as hard as 4130 can be tempered to.  Normalized 4130 tube seems to be anywhere from 63-75KSI so again comparable to 7075. The plus with 4130 is you can temper it to much higher yield strengths. 

So the only issue with 4130 is that when you increase the strength of steel by adding carbon, chromium and molybdenum, the material also become more prone to cracking.  The key to preventing this with 4130 is having an extremely clean weld by ensuring the material is clean (free of oil, rust etc.), shielding with the correct gas and very importantly that the proper electrode is used.  After welding you should do a post weld heat treatment of the link.  This will relieve stresses built up in the material from welding as well as hopefully pull out any free hydrogen that may have been introduced during welding that can cause hydrogen embrittlement if it was absorbed into the surface. (Which can cause cracking and failure) The good ol Hydrogen atom can pass through solids and causes major issues in industry.  Simple moisture in the air can cause problems, and I’ve seen it effects firsthand at work.

You can try to limit the hydrogen absorption by doing a pre heat followed by a post heat and wrap in a weld blanket. Uncontrolled quick cooling is an issue.  Your weld and HAZ will still be compromised and the week area if not heat treated and should be inspected for cracking regularly IMO.  Ideally these should be vacuum heat treated and then cooled by flushing with argon at a controlled rate to cool them.  Prior to this you can clean them in an ultrasonic vapor degreaser.  Zero issues then.


I found that you can buy custom 4340 links that are heat treated at bent fab.  (I saw others on Pirate)  I didn't call to ask what exact heat treatment process they have  performed so yeah.. 
https://www.bentfabaz.com/hardcore-links-s/113.htm

 

Bill Nye the Science guy over here and I really appreaction it, unless you said this I would have just assumed it was a normal weld process. I know for all the brackets I added to my POSUD axle I wrapped them and let them cool as slowy as possible, but I dident know there was a extra process for 4130. I know Syneregy uses 4130 on all there steering stuff but who uses 4130 for arms?  Are most just made out of 1026 DOM?

[Dave]

3 hours ago, AJK said:

 

  my POSUD axle 

 

[Crawl2Camp]

9 hours ago, AJK said:

Bill Nye the Science guy over here and I really appreaction it, unless you said this I would have just assumed it was a normal weld process. I know for all the brackets I added to my POSUD axle I wrapped them and let them cool as slowy as possible, but I dident know there was an extra process for 4130. I know Syneregy uses 4130 on all their steering stuff but who uses 4130 for arms?  Are most just made out of 1026 DOM?

LOL. Sorry Alan, I just re read my reply right now.  I was trying to explain things and got a little carried away as I went on.  

One of my jobs at work is actually to set up all of the weld procedures per the AWS specifications.  I have to do that plus quite a bit more on our Cal Trans bridgework jobs etc.. I was actually working on becoming an AWS CWI before I got injured.  Thats still my number one goal when I get back.  

As far as your axle and brackets they are fine.  The tubes are just 1000 series DOM and your brackets are more than likely just A36 steel.  

For JK’s I haven’t see anyone make 4130 links that are off the shelf.  Cost is a major factor.  I have seen it used in the IFS trophy trucks and Ultra4, and it’s all processed correctly.  I follow a few fab guys on instagram that do some amazing work for those guys.   From what I have read, most all off the shelf JK arms are 1026.

Yeah I'm pretty confident that Synergy heat treats all of their steering systems after weld.  Dave is a smart guy and owns multiple businesses besides synergy; from a medical supply company to some involvement in defense. 

[Crawl2Camp]

9 hours ago, Dave said:

I can sense the frustration building and have a solution for this..  
Order a set of new axles exactly the way you want them from Matthew/ECGS.  Clean up and sell you current POSUD 1 tons and I bet you break close to even or only spend a minimal amount.  

Edit:  Wait I just remembered that you like the Currie axles.




 

[AJK]

12 hours ago, Crawl2Camp said:

I can sense the frustration building and have a solution for this..  
Order a set of new axles exactly the way you want them from Matthew/ECGS.  Clean up and sell you current POSUD 1 tons and I bet you break close to even or only spend a minimal amount.  

Edit:  Wait I just remembered that you like the Currie axles.




 

LOL, that is the plan after CO.

[AJK]

Kevin refresh my memory when are you planning on doing the front? I drive passed you down the 71 every day. I would like to swing by and see once you have this on.

 

Also, what DOM would you say is best for lower control arms other then 4130?

[Crawl2Camp]

1 hour ago, AJK said:

Kevin refresh my memory when are you planning on doing the front? I drive passed you down the 71 every day. I would like to swing by and see once you have this on.

 

Also, what DOM would you say is best for lower control arms other than 4130?

I ordered the kit a month ago from RPM; I’m hoping it will be here in the next week or two.  I’ll let you know when things get cooking. 

To be honest, I’d personally either run 4130 or 7075 links.  Knowing how you and everyone here is constantly pushing things, why compromise over what a few measly hundred dollars?  You’ve already bent an EVO’s short arm with a thick DOM tube.  Longer arms require higher strengths as there is more leverage on things. If you want 4130 I’d just measure and buy custom made and heat treated links.  I know you guys try and do it all yourself, but sometimes you have to bow out to get the primo stuff.  

[AJK]

46 minutes ago, Crawl2Camp said:

I ordered the kit a month ago from RPM; I’m hoping it will be here in the next week or two.  I’ll let you know when things get cooking. 

To be honest, I’d personally either run 4130 or 7075 links.  Knowing how you and everyone here is constantly pushing things, why compromise over what a few measly hundred dollars?  You’ve already bent an EVO’s short arm with a thick DOM tube.  Longer arms require higher strengths as there is more leverage on things. If you want 4130 I’d just measure and buy custom made and heat treated links.  I know you guys try and do it all yourself, but sometimes you have to bow out to get the primo stuff.  

Nice, I am really looking forward to seeing this kit.

 

For the arm I bent the long arm and I am only looking for a temporary fix for a few trips until I make the jump to the next setup. Make is simple and cost effective for a short time.

[Crawl2Camp]

31 minutes ago, AJK said:

For the arm I bent the long arm and I am only looking for a temporary fix for a few trips until I make the jump to the next setup. Make is simple and cost effective for a short time.

Sorry, I forget about the trip you guys are going on. 
IMO if it’s temporary just use whatever DOM you can get your hands on that will work for you dimensionally.  

[AJK]

So, came across this today. I know it's not RPM but take a look and tell me if you think the price for the arms is fair.

 

Apparently they cut to the length and will tap to the size you want.

 

https://www.wideopendesign.com/aluminum-links?fbclid=PAAaaWfLicg8TRf4ZXQ6xcxEk67BKwIXSJJaVPhN8QErfD-Gtry7qJ90MRzUA

[Crawl2Camp]

3 hours ago, AJK said:

So, came across this today. I know it's not RPM but take a look and tell me if you think the price for the arms is fair.

 

Apparently they cut to the length and will tap to the size you want.

 

https://www.wideopendesign.com/aluminum-links?fbclid=PAAaaWfLicg8TRf4ZXQ6xcxEk67BKwIXSJJaVPhN8QErfD-Gtry7qJ90MRzUA

Sorry Alan, the provided link doesn’t have the arm information input in the form, so it doesn’t show the price.  You can get 7075 arms from: RPM, Wide Open, Summit Machine, Busted Knuckle, Bent Fab etc, and the links themselves are not all that expensive.  The RPM 7075 2” tie rod replacement I just purchased was 39” long, tapped ends for the Rare parts 2.5 ends, has their nice wrench hex’s and was only $179.  I did not price out the other companies because I didn't feel there was any reason to and I also was able to get a double shear ram clamp from him as well. 

[MIOffroadCustoms]

I get all mine through Busted Knuckle! Fast and very reasonable!

[Weebz]

7 hours ago, MIOffroadCustoms said:

I get all mine through Busted Knuckle! Fast and very reasonable!

And beautifully finished.  

[Crawl2Camp]

My new front lower control arms. (2.25” D)

[702Jeep]

Oh man those are beautiful !

2 hours ago, Crawl2Camp said:

My new front lower control arms. (2.25” D)

 

[AJK]

Are you going to paint them gold or is the can for size reference?

[Crawl2Camp]

37 minutes ago, AJK said:

Are you going to paint them gold or is the can for size reference?

It’s for size reference.