Infraction A arm replacement help

[bladefan]

Hey guys,

I broke a front A arm And am trying to replace it. It looks like I have to take whole front bulkhead off the chassis to get at it? It seems like a lot of work just to replace the a arm? Or am I missing something? Thanks!

explanation of what happened in case anyone cares-
I lost control going kinda fast trying to show off. My driveway has a ramp at the corner and I slid sideways into the ramp and went airborn into the tree. It looked like it hit in the cab region first so I’m surprised I broke an an arm.

 

[SrC]

How it happened is ok. Driver error. Part of the game in RC. May be your first time, just not the last arm to break. We all break these. They are meant to be the first to break. And easiest to replace. If the weather was very cold, understand that it doesn't take much for the arms to break, Plastics get brittle. I rarely drive my RC's in the frigid weather because of this . When I do, I drive more cautiously.
No need to take off the complete bulkhead at all.
Need to remove the bumper, gaining access to removing the Arm Hinge pins "A Block".
There are many videos in regards to this. It is easy. A learning curve, that you will master easily. Done just one time. The rest becomes muscle memory. Learn by doing.
Good luck.
Get back if you have any issues going forward.

 

[bladefan]

Thank you! I tried searching but wasnt getting what I wanted. Will try the a block term

 

[SrC]

let me try to find you a great video or 2.
You listed a Granite and Infraction as your rigs. I guess you are talking the Infr. because this thread in the 6s catagory?
What rig are we speaking of?

 

[bladefan]

Infraction
Also, Ive been reading your fireteam post today. I got a felony thats still in the box and I want to do a tear down like you talk about. I watched a video about shimming diffs on the outside (between the diff and the bulkhead). And I remember you have linked me in the past the mugen diffs for inside the diff (I was getting all this confused). now Im gonna go watch a video on that. Is there a video you recommend about tearing down the felony to check for problems?

also, do you list ALL the problems for HH (like loose grub screws) or just the parts you want a warrantee for ?

thank you SRC

 

[SrC]

Wow.
Of fall my 6s rigs I never broke any arm on my Infr.
Wrecked it bad, twisted the chassis, but never an arm.
Anyway.... Let me find a video or 2 . Best to watch a few. Because you learn easier seeing different ways of doing it.

 

[bladefan]

haha! I haven’t twisted the chassis yet. But I think it’s a little bent. I’m gonna try the CF sleeve you have shown (thanks I see many have copied ur idea!)

also just stumbled on earl moreheads tear down of an infraction

 

[SrC]

At aprox 2:16 min into this video. It shows you what you need to remove. Bumpers etc. to get to the Arms' Hinge mount plate. (aka A block) Probably the longest part of replacing the arm is just removeing the Bumper parts. You can take pix as you do this so reassembly will be easier. For reference as you go. Just organize the screws as you remove them in order. Helps.
This video continues onto the Diff removal process, but you can disregard it. Yo will see at this point there is a red plate that comes off, this is also called the A Block by many. A Universal RC term. Once removed the arm hinge pins are loose and the arm(s) come out.
I hope this helps. It is rare to break an Infr Arm. They are short and the body protects the arms most of the time. So there aren't many videos specifically in regards to the Infr/Felony about Arm replacement. Procedure is basically the same for any 6s rig. The Infr Front bumper is concealing much of what you need to see and get to. So this video can be helpful.
Earl M. is cool too. Just a bit long winded. Much to learn from him also. Raz Shifrin has very good videos. Knows the Infr chassis very well. Makes it look like childs play . And it actually is. Good to pause his frames for reference.
Good luck.

 

[bladefan]

Thank you very much! I had gotten the bumper off already but still couldn’t figure out what to do without taking everything all the way apart. Thanks for the video! Will check it out now!

 

[SrC]

haha! I haven’t twisted the chassis yet. But I think it’s a little bent. I’m gonna try the CF sleeve you have shown (thanks I see many have copied ur idea!)

also just stumbled on earl moreheads tear down of an infraction

I can't take full credit for that CF sleeve mod. I just keep recommending it though, versus buying new Upgrade T2T's.
It was a big thing when the 6s V4 T2T's became a standard Arrma part. Just the stocker T2T's would still bend often . Sleeving it was the fix. Then a year later, Solid CF upgrade T2T's started appearing as well as 7075 variants. Costly at that. I think its cheaper to sleeve them. Never bent any of them since.
Would have probably cost me like over $300. to buy Upgrade T2T's, compared to about $80. I spent for all my CF sleeved ones in all my 6s rigs.

 

[bladefan]

Thank you very much! I had gotten the bumper off already but still couldn’t figure out what to do without taking everything all the way apart. Thanks for the video! Will check it out now!

———
hmmm. there is something in front of the red plate blocks Access to the “A” block screws so I can get the pins out.

it looked like to me, you Had to get the differential bulkhead off the chassis to get at it. And because the whole steering assembly is there too have to deal with that. Although if I had the bearings for the bell crank it would be a good opportunity to replace those. I think I will try the Amazon Servo’s you have recommended in past posts as well.

 

[SrC]

.

 

[bladefan]

I just ordered the servo and cf sleeve.
yes, in that last pic is the plastic blocking the red plate. But I see I might have missed the obvious thing of getting it easily out. Maybe sleep deprivation is making it harder than it looks.

 

[SrC]

Been there.... if you are tired put it down and come back to it another time. I have had long nights wrenching, Only to find the next day, being tired, caused me to disassemble it all again from mistakes and screws I missed.

 

[bladefan]

This is the broken a arm still has pin it. I think I’m gonna have to dremel it out. It’s bent on both ends. If I had a spare it wouldnt bother

Lol didmy realize I could slide this blocking piece out by taking out 2 more screws.

 

[Dan B.]

This is the broken a arm still has pin it. I think I’m gonna have to dremel it out. It’s bent on both ends. If I had a spare it wouldnt bother

View attachment 265406

View attachment 265405
Lol didmy realize I could slide this blocking piece out by taking out 2 more screws.

View attachment 265407

Dude, I admire your tenacity in trying to straighten them, but those things are shagged. Buy more pins, man. You can probably get them close, but they will probably bind and round out your new a-arms.

Lol didmy realize I could slide this blocking piece out by taking out 2 more screws.

Like @SrC said, it’s a learning experience. Next time will go a lot quicker for you!

 

[bladefan]

Dude, I admire your tenacity in trying to straighten them, but those things are shagged. Buy more pins, man. You can probably get them close, but they will probably bind and round out your new a-arms.

Like @SrC said, it’s a learning experience. Next time will go a lot quicker for you!

Ya you’re right. I just some time trying to straighten. It sucks. I’m not sure I made any progress and I’m tired of it lol

 

[Dan B.]

Ya you’re right. I just some time trying to straighten. It sucks. I’m not sure I made any progress and I’m tired of it lol

Got any drill bits of the same diameter that you can cut to length? The world doesn’t need any more freaking holes anyway, man.

 

[SrC]

That Hinge pin is mangled in a few directions. I've straightened ones that were bowed slightly. It will never bend with pliers or similar. You need a block of wood and a sledge hammer, Maybe vice grips or a vice to hold one end while you hammer it, to get it close. Plenty of time and patience may work. I don't think yours will become straight enough to insert into the new arm. If you force it to, it could also stress out the new arm. The hinge pin should smoothly rotate once installed. I would consider a new set of pins if possible. Work with what you got in the mean time. Those pins are super strong to bend back straight. Will leave you wondering how hard the crash was to bend it in the first place. Also, maybe polish it up in a drill to make it slide better before installing. Some tips. When Arms snap or break, 90% of the time the hingepin is also bent, FWIW. Also, a slight bend in a hingepin will alter the wheel alignment a bit.
Good luck.