RC Axle Master's Straight 4340 Chromoly Straight Axles

[Cruzin Illusion]

Awhile back I was looking for the perfect rear axle lockouts for the berg that I was building. After I weighed my choices, I decided that CKRC's Straight Axle Conversion was my top choice. CKRC's kit had everything I was looking for. An actual straight axle shaft, an axle adapter that would provided optimal clearance and no sharp edges to hang up on the rocks. Needless to say, after a few runs with the crawler, I noticed that the rear tires would wobble back and forth do to the axle shafts being bent. I thought it was just a fluke when my wifes crawler became the same way. I got a hold of CKRC and purchased a replacement set of shafts for the wife and I along with a spare set of shafts. During the Midwest challenge my wife snaped a long side shaft so that took out the spare I had. Again I contacted CKRC and ordered a couple more sets. After bending a substantual amount of the CKRC shafts I contacted Jake at CKRC and told him what I thought the fix could be. He agreed and soon Jake had another machine shop making his shafts. Soon as CKRC had the new improved shafts in stock I order a few sets. After one run those shafts were also bent. So long story short I contacted Steve from RC Axle Master and explained the situation. He was making replacement shafts for the Bully and he was in the process of coming up with a replacement shaft that would work with any type of axle conversion or lockout made for the Berg. I asked if he could have a set built by Worlds so I would not have to worry about changing shafts during the comp. After a week and a half he had them at my door and they are everything he describe plus some. The straight axles are made of 4340 chromoly and will work with the CKRC axle adapter and anyone's rear axle lockouts. They are a 6mm shaft with the M5 thread. If your lockout is getting loose they will not be after the axles are installed. He has a small supply that he can send to people that want them for the World's comp. Send email to rcaxlemaster@embarqmail.com and Steve will give you more info on the axles. These axles will be sold through RPP Hobby once he gets the bearing supply in for the kits.

Here is a write up for the install of RC Axle Master's Berg Rear Replacement Straight Axles:

Here is the inventory with what come in the kit:

1. (1) short side axle shaft
2. (1) long side axle shaft
3. (2) 6mm x 11mm x 4mm bearings
4. (2) 6mm x 10mm x 3mm bearings
5. (2) Brass Spacers (used when using stock knuckles)
6. (4) C-clips
7. (2) 5mm nuts




My assembled axle with CKRC lockouts:


1. Remove the 12mm hex:



2. Remove the knuckles and lockouts, axle adapters, or bolt on lockouts.

(Pictured is the CKRC axle adapter)



3. Remove the inner axle shaft along with the bearing inside the axle tube.

( Pictured is a straight axle from the CKRC kit)





INSTALLATION ON THE 4340 CHROMOLY STRAIGHT AXLE SHAFT:

Installation instructions will very depending on what type of lockout or axle adapter you are planning on running.

1. Install a new 6mm X 10mm x 3mm bearing into the end of the axle tube. Make sure the tube bearing is seated all the way back. There should be a 1mm space from the front of the tube to the bearing.






2. (For CKRC Straight Axle Kit)

a. Replace the 5mm x 11mm x 4mm bearing in the CKRC Axle adapter with a new 6mm x 11mm x 4mm bearing that comes in the kit.



(For those using Lockouts with Knuckles)

a. On the knuckle replace the 5mm x 11mm x 4mm bearing located on the outboard side of the knuckle with a new 6mm x 11mm x 4mm bearing that comes in the kit.



b. Replace the bearing on the inboard side of the knuckle with a brass spacer provided in the kit.



(For those using JP Customs type of lockouts)

a. Install the brass spacer that is in the kit into the lockout.



INSTALLATION OF THE AXLE SHAFT

1. Before installing the axle shaft into the axle tube you will need to install 2 of the C-clips provided into the correct slots depending on what type of lockout you are using.

a. If you are using a CKRC axle adapter you will want to install the C-clips on the most inboard and most outboard slots.

b. If you are using a lockout and knuckle or JP customs type of lockout you will want to install the c-clips on the most inboard and middle slots.

The pictures below show the proper installation of the c-clips when using a CKRC axle adapter.





2. Install the axle shaft into the axle tube.

[slowngreen]

very nice!

[Cruzin Illusion]

INSTALLATION OF AXLE ADAPTER, KNUCKLE AND LOCKOUT, OR JP CUSTOMS TYPE OF LOCKOUT.

For CKRC axle adapter

1. Slide adapter over the tube end and reinstall the two 3mm screws removed during disassembly.

For Knuckle and Lockout

1. Install the lockout over the axle shaft and reinstall the knuckle (make sure the hat bushings are installed) with the two 3mm screws that were removed during disassembly.

For JP Customs Type Of Lockouts

1. Install the JP Custom type of Lockout using the two 3mm screws removed during disassembly.

Picture shows CKRC Axle Adapter



REPEAT THE PROCESS FOR THE OTHER SIDE OF THE AXLE:

[Cruzin Illusion]

12 MM HEX MODIFICATION:

Now is the hard part of the assembly. You will need a 13/64 and a 15/64 drill bits. They will be used to modify the wheel hexes.

1. First use the 13/64ths drill bit and run it through the existing hole. This hole will clear the M5 thread.



2. Next you will use the 15/64ths drill bit, and from the pin groove side of the hex, drill it about 1/32nd past the pin groove. This will clearance the wheel hexes to fit over the end of the 6mm shaft.







NOTE:

If the holes in your wheels are too small for the 6mm shafts you will need to drill them out to the 13/64ths hole size.

INSTALLATION OF THE MODIFIED HEXES:

1. Install the pin through the axle shaft.

2. Install the hex onto the axle shaft.

[Cruzin Illusion]

THE DIFFERENCES IN AXLE SHAFTS:

You can see the shaft size difference and thread size difference.

Original shaft size was 5mm and RC Axle Master's Chromoly Shaft is 6mm.

The original thread size was 4mm and RC Axle Master's Chromoly threads are 5mm







Now it is time to reinstall your wheels and have some fun crawling!!!!!

Pictures of the finished product.

[LetsHandleit]

Thanks for posting your install very nice.

[roksloski]

Very nice...
good write up....

And the cost is???

[dieselfuel]

awesome write up! you're gonna like them, i havent been able to hurt mine yet.

[Pappy]

Originally Posted by roksloski

Very nice...
good write up....

And the cost is???

Agreed!

Yes, how much?

[dieselfuel]

i believe the kit will land in the $70 range.

[Pappy]

Mine are ordered and on the way!!!!!!!!

[Cruzin Illusion]

Originally Posted by roksloski

Very nice...
good write up....

And the cost is???

I believe the kit is going to be in the $71.00 range.

[Pappy]

Originally Posted by Cruzin Illusion

I believe the kit is going to be in the $71.00 range.

Worth it IMO, if I can stop bending and snapping axles! Mine are on their way to me.

[samaruki]

very good info for a noob. saving this for sure..

may i ask what are you using to cover your axles shaft and motors?

[Szczerba]

Thanks for this thread. My CKRC shafts are staring to bend.

Ordered a set. Super fast response from RC Axle Master.

Just a note on the CKRC lockouts. I had to use 4 set screws on each adapter to get them to hold straight.

...

[yotachump]

Are the shafts hardened?

[dieselfuel]

Originally Posted by yotachump

Are the shafts hardened?

no they're not, just 4340 chromoly.

[LetsHandleit]

Originally Posted by yotachump

Are the shafts hardened?

No, the Bully axles have been out for a few months now and I never had them hardened and have not had any returns. The 4340 chrome-moly is plenty hard and with the 6mm shaft and M5 thread they are super strong. These axles if purchased should be the last set of axles you will need. I'm sure someone out there is going to bend one at some time, but I don't think you will see it break.

[LetsHandleit]

Originally Posted by Shane_744

Thanks for this thread. My CKRC shafts are staring to bend.

Ordered a set. Super fast response from RC Axle Master.

Just a note on the CKRC lockouts. I had to use 4 set screws on each adapter to get them to hold straight.

...

If the adpaters are straight with the 4 screws there should be no problems. The new straight axles will also hold the adapter straight. If you should have any problems just contact me and I will help.

[Almighty Malach]

Originally Posted by dieselfuel

no they're not, just 4340 chromoly.

Yeah, just lol. I'm sure these are worth it, but I have yet to bend the CKRC shafts yet. How many guys are gonna be dropping 200 bucks on these and the 300m cvds I wonder?