Big Rock Steel Diff update

[morrjr71]

I'm using the plastic yokes that came with the CNC steel diffs. The CNC diffs are as smooth as glass out of the bag, and I didn't see the need to replace the plastic yokes with the HR yokes I had previously on the stock diffs.

 

[JPWSRC]

It's hit or miss for me with the arrma yoke vs the HR yoke. On my OC4 the arrma yoke didn't make it through 1 battery pack with the CNC gears but on my K4 the composite yoke is working well with the same diff build.
Based on my observations the metal input ( pinion) can be shimmed deeper into the crown ( ring ). Currently both my 4s cars diffs have .4mm of shims on the crown side.

 

[Velodromed]

It's hit or miss for me with the arrma yoke vs the HR yoke. On my OC4 the arrma yoke didn't make it through 1 battery pack with the CNC gears but on my K4 the composite yoke is working well with the same diff build.
Based on my observations the metal input ( pinion) can be shimmed deeper into the crown ( ring ). Currently both my 4s cars diffs have .4mm of shims on the crown side.

What shim size for the input gear? Thanks man! This all makes sense. I’ve got my parts arriving this week and I’m excited about putting together my first metal diff.

 

[JPWSRC]

What shim size for the input gear? Thanks man! This all makes sense. I’ve got my parts arriving this week and I’m excited about putting together my first metal diff.

I'm sorry buddy, I didn't take measurements for the shims and don't have a loose steel input gear to measure. I believe a .2 mm thick shim should be all you'd need. Just get the input bearings ID and that'll tell you what size.
Here's a video @jondilly1974 did a year or so ago about the subject.

 

[Velodromed]

I'm sorry buddy, I didn't take measurements for the shims and don't have a loose steel input gear to measure. I believe a .2 mm thick shim should be all you'd need. Just get the input bearings ID and that'll tell you what size.
Here's a video @jondilly1974 did a year or so ago about the subject.

No worries, thanks for that video!

 

[car_006]

Update on my exb diff gears and hot racing yoke. I took it to a skate park yesterday and it was a blast. I had no issues with the diff, and I really like the 100k fluid in the front. My spur gear did start to shred itself, though. I think it was because my motor screws came loose.

 

[brianu]

Doesn't take much to upset the spur and pinion mesh, lucky you found it.

So far my metal rear diff is holding up 100%. 20 or so packs through and I'm certainly over the taking it easy period and driving it (for me) quite aggressively. Well worth the money IMO.

I drive mine like miss daisy and still keep ripping thru diffs. I got the metal cnc diff for typhon 3s. Any pointers? Will this cause any issue with other parts? Or should I put stock in.

 

[RCbuzz]

I would put it in, I do not think mixing the Arrma CNC diff's with the plastic (front / rear) would have any impact at all, I believe the gear ratio is the same. Just be sure the complete diff assembly is metal (example, diff ring and input gear). If purchasing the prebuilt Arrma one that will not be an issue since they come as a drop in assembly.

150$ for two diff's though... Ouch....

 

[BulletRCs_NZ]

I drive mine like miss daisy and still keep ripping thru diffs. I got the metal cnc diff for typhon 3s. Any pointers? Will this cause any issue with other parts? Or should I put stock in.

Just put it in. Direct replacement as long as it's the complete diff set.