Can't catch a break - broke an a-arm

jjorgensen52

jjorgensen52

NHSTE - I'm the only one!
Just got a picture from my Dad, he drove my Ty yesterday from NH to Cape Cod and somewhere along the way near Boston this happened:

brokenaarm.jpg


3 year old RPM arms with about 3500 miles on them. It's not broken off, to the arms credit it made the remaining ~90 miles of the trip like this, but still sucks.

Just for reference, not flaming RPM or Mike (will be calling him tomorrow when the shop opens) in any way, just ticked that my truck is broken AGAIN. Not 300 miles after I blew apart my lifters and had to rebuild the engine. :rant:
 
mattw

mattw

Active member
Re: Can't catch a break - broke an a-arm

Wow, thats kinda scary.. Makes me think that sticking with the ugly stock lower arms probably isn't such a bad idea..
 
M

MikeRenz

not stock
Re: Can't catch a break - broke an a-arm

creditting the arm for not completely shearing off? what would possibly make the arm break there aside from takin that truck off some sweet jumps?

i can't believe you drove it that way. just a tad off from safe
 
jjorgensen52

jjorgensen52

NHSTE - I'm the only one!
Re: Can't catch a break - broke an a-arm

MikeRenz said:
creditting the arm for not completely shearing off? what would possibly make the arm break there aside from takin that truck off some sweet jumps?

i can't believe you drove it that way. just a tad off from safe
Click to expand...

The roads in New England suck. That's my conclusion. Potholes do nasty things to suspension.

As for driving it like that: if he (or I) had known it was bent / broken like that, the truck would never have moved. This happened enroute and wasn't noticed until the next morning when they were looking at the truck (the wheel looks funny since the ball joint isn't where it's supposed to be anymore)

I was the last person to drive the truck prior to this, and I was underneath it checking on things so I am 100% sure that the arm was undamaged prior to this trip.
 
43t_ftw

43t_ftw

Member
Re: Can't catch a break - broke an a-arm

bezerk said:
i feel safe with the budget coilover now.
Click to expand...

haha ya.. makes me feel better about my decision to be a cheap ass and keep the stock a arms :rotf:

shitty luck tho man, hopefully rpm will do something to help you out..
 
jjorgensen52

jjorgensen52

NHSTE - I'm the only one!
Re: Can't catch a break - broke an a-arm

bezerk said:
i feel safe with the budget coilover now.
Click to expand...

Jeez... Can't you people just let this rest? :squint: I'm only posting to let everyone know about my bad luck. My truck is broken all the time anyway. I'm not trying to say anybody made a bad product or anything else.

I hope the mods will lock this up if it starts turning into a flame-fest :2cents:
 
JSM

JSM

Active member
Re: Can't catch a break - broke an a-arm

Ok, I am responding purely from an engineering standpoint and to ease the minds of anybody running JSM arms.

There is a major difference in the design/construction of the 2.

RPM felt it was important to duplicate the stock GM ball joint angle, in doing so the flange had to be different. This involved putting a bend in it, and shortening the tubes. You can see that on his webpage.

LINK

On my design I changed the balljoint angle for several reasons. 1 it made the design easier, it allowed me to make the tubes longer and support the balljoint better.

LINK TO JSM ARM DESIGN

So those with JSM arms will not have this issue. I have a truck in my driveway with my arms on it and the owner is guessing it the arms have around 100k miles on them.

JSM customers continue to sleep just fine.
 
MRKING

MRKING

New Parts for Old Trucks
Re: Can't catch a break - broke an a-arm

shit , i started the stock arm swap revolution and just recently did the rpm arms to save the extra weight . i hope it was a wise choice . people have been running them for years so far , so im not really worried .
 
eviltwin

eviltwin

"junkyard syclone"
Re: Can't catch a break - broke an a-arm

wow that sucks. you must be on some drugs if you are this calm about it
 
bezerk

bezerk

New member
Re: Can't catch a break - broke an a-arm

yeah man, thaqt shit is scary if you do a 1/4 mile with a 120mph speed.
 
BigBadSmoosh

BigBadSmoosh

Picking fights on I-65 since 2013
Re: Can't catch a break - broke an a-arm

obviously a design failure.. going to be an expensive replacement for the manufacturer. either that or he just should not sell them to anyone in the northeast.

usually stuff like this is cause for a recall of all of the parts designed this way.

OUCH.

glad you made it home safe, and hopefully there isn't any further damage to the truck.
 
Jimmy

Jimmy

Banned
Re: Can't catch a break - broke an a-arm

TwinTurboV8Ty said:
Ok, I am responding purely from an engineering standpoint and to ease the minds of anybody running JSM arms.

There is a major difference in the design/construction of the 2.

RPM felt it was important to duplicate the stock GM ball joint angle, in doing so the flange had to be different. This involved putting a bend in it, and shortening the tubes. You can see that on his webpage.

LINK

On my design I changed the balljoint angle for several reasons. 1 it made the design easier, it allowed me to make the tubes longer and support the balljoint better.

LINK TO JSM ARM DESIGN

So those with JSM arms will not have this issue. I have a truck in my driveway with my arms on it and the owner is guessing it the arms have around 100k miles on them.

JSM customers continue to sleep just fine.
Click to expand...

Are you saying that RPM ripped off your design,then modified it to fail?


WOW. :roll:
 
MRKING

MRKING

New Parts for Old Trucks
Re: Can't catch a break - broke an a-arm

I love jeff like everyone else ( maybe more than you know, hehe ) , but why were the js arms even mentioned in this thread ? maybe some thread cleanup is in order .
 
M

MikeRenz

not stock
Re: Can't catch a break - broke an a-arm

MRKING said:
I love jeff like everyone else ( maybe more than you know, hehe ) , but why were the js arms even mentioned in this thread ? maybe some thread cleanup is in order .
Click to expand...

so that those using his a-arms can rest assured that the manufacturer of their product are standing behind their design
 
jjorgensen52

jjorgensen52

NHSTE - I'm the only one!
Re: Can't catch a break - broke an a-arm

smaug said:
obviously a design failure.. going to be an expensive replacement for the manufacturer. either that or he just should not sell them to anyone in the northeast.

usually stuff like this is cause for a recall of all of the parts designed this way.

OUCH.

glad you made it home safe, and hopefully there isn't any further damage to the truck.
Click to expand...

Further examination has revealed:

The arm pictured (passenger) has sheared completely at the forward tube (what you can see) approx. 3/4" into plate. There is stress cracking at the back tube. The change in geometry has caused the CV joint to rub on the lower spring perch.

The drivers side (no pictures) has suffered minor bends and cracking at both forward and back tubes (no failure as yet). On this side the tie rod is making slight contact with the spring perch (I expect the bolted collar has rotated and is an easy fix) Also, the ball-ends in the shock (both upper and lower) are shattered on this side, which has happened before so I'm not overly concerned about it.

Both sides have mild bending apparent in the upper arms, but not 100% sure if that is the original angle or the stress from the damage to the lower arms caused further complications.

The full story about how this happened is that the truck hit a serious of "bumps" from bridge work just outside Logan airport in Boston. Dad said there were 4 bumps and that the 4th one was the one that broke the arm. This occured at speed (65 - 70mph). Following that, the truck felt wrong at anything over 50mph, so Dad pulled in at the airport (picking up my brother) and looked under the truck, but being late and without a light they didn't see anything immediately wrong. The truck then made the rest of the trip at 65 - 70mph without incident and no evident change in ride or handling.

I'll be calling RPM tomorrow to discuss this with them. Until then, I'm thankful the truck made it safely home and nothing more serious came of it. My dad and brother are looking into effecting enough repair to the arms for the truck to make the trip back home where I can fully repair it, but if it can't be made road worthy it's not going anyplace. Of course, I won't be home (I'm in Alaska right now) until the middle of August. Go figure.
 
MRKING

MRKING

New Parts for Old Trucks
Re: Can't catch a break - broke an a-arm

MikeRenz said:
so that those using his a-arms can rest assured that the manufacturer of their product are standing behind their design
Click to expand...

well i didnt pay for em so hopefully they were worth that much .:lol: but the reason i aquired them is not really helpful to mike case really. a local kept blowing out drivers axles (at least 3or4) and traded me his front kit for my modified stock setup . he thought the arms were bad and was tired of dealing with it .
 
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