Good News Bad News!
 

Well the modded MMM is holding up great on 6s As123 2p with a 1515 2.5DF...

Sadly the RCM hybrid diff's couldn't take the power and the output shaft sheared!

http://i168.photobucket.com/albums/u180/Arct1k/009.jpg

WOW!!! That is some serious power...just what we all like. Although we could do with out the broken parts, but that is the fun of our hobby!

I gotta think that shaft was overhardened to shear like that - or it was damaged at some other time. The tires on these trucks cant provide enough friction to transfer the amount of torque to shear metal like that.

wow

hopefully rcm will replace it

i have sheered several trani input and output shafts but not diff shafts....i only use UE though!....they are the BEEF!....try them!

That's not surprising. Just look at the amount of missing metal due to the hole bored to the shaft. Ever wonder why buggy/truggy pinion shafts don't have a hole on them?

Matt, you sheared them for the same reason I stated above. The output shafts have holes bored into them for the setscrews which reduced the amount of metal needed for strength and durability. The shafts are hollow due to the hole instead of being solid like the buggy/truggy pinion shafts.

In the photo, in the lower left side, there looks like there is a hole/dent in the material. That looks like its possible a bad spot in the material (could be a void/inclusion) that could have been the cause of the shear. Can you get a better picture of it? Do you have the mating portion? If you look at the material, it should all look like the upper right portion if the damage was 100% shear.

I have sheared the pinion on a V1 RC-M diff conversion, but not the output

Humbug! I've gone and done it again! Another one sheared!

Just get the UE diff outputs and you'll be good to go :intello::whistle:.

Was that with the new Nue?

That was with a Neu1515 2.5 DF - The blinking set screw is stripped on the pinion so I can't take the motor off to install the CC 1515!!!

I drilled out what I could and thought I run to the see if I could get it to slip - no dice yet!

Pointers would be appreciated to those UE outputs

Any reason that you could not use different bearings and the std non-machined 8mm pinions? Will the v1 cases not allow for the correct size bearings? I only ask I have a set of v1s and wonder how they will handle the 1521 on 6s....

UE diff outputs. They are out of stock though.
http://www.unlimitedengineering.com/...ore/85037.html

Or you can try truggy/buggy diff outputs such as these. Just cut the threaded portion off.
http://cgi.ebay.com/NEW-4-6-SAVAGE-X...1%7C240%3A1318

I need this though... The issue though is for some reason the side on the left is milled flat which makes it much weaker...

http://www.rc-monster.com/prodimages...haft%20web.JPG