Kraton Kraton 4S Differential issue

[theapplepilot]

Hi,
I know almost nothing about RC and recently my rear differential has been making a loud grinding sound. I've been thinking about replacing it but I've read online that its better to use anything other than the stock diff. Can someone tell me if i actually need to change my diff or if its something else. And if I do, which diff should i use?

Thanks

 

[SrC]

You "read" wrong, There is much misinformation out there online. and you probably misread, if anything.
You have a learning curve going on. It's all good.
Baby steps.
Replace the diff with stock parts.
Don't be so quick to even "think" about upgrading. At least right now.
Work with and learn about what you got in front of you. Keep it simple. Learn how to wrench what you have there first.
And tame your driving better in the beginning.
Or you will be chasing broken parts more often.

 

[RCbuzz]

The 4S diff is considered a significant upgrade for 3S trucks .

They are sintered so I am sure not all created equally.

The important thing is to shim them correctly. One upgrade that will benefit you is a metal yoke, it prevents the diff and input gear from losing mesh under load.

 

[MrTitanium]

More info needed. Post pics in order for us to help you diagnose the cause(s) of the breakage.

Also, the stock metal parts aren’t the strongest on the market. Might want to consider the steel CNC components.

 

[SrC]

@theapplepilot has a 4s platform with stock metal gears. Being new to RC as well.
Could just be user/driver error or simply time to replace worn parts and learn maintenance better.. Parts wear out. Replace with stock and keep rolling.
Am I wrong. Upgrade main gears sets don't come cheap.

 

[theapplepilot]

More info needed. Post pics in order for us to help you diagnose the cause(s) of the breakage.

Also, the stock metal parts aren’t the strongest on the market. Might want to consider the steel CNC components.

Took it apart. Here’s some pictures. There was quite a lot of black powder.

 

[theapplepilot]

Does this look fine to you guys. My K4 recently started making a loud grinding noise but still has power. It’s definitely somewhere from the motor/Center diff but I don’t wanna buy anything before being sure. Please help

 

[Eno]

That is a slipper clutch, not a center diff.

 

[slick2500]

Pull the motor out. $100 says the front bearing is done. See all that crap all over the place, that is also inside the front motor bearing and most likely inside the motor as well.

 

[MrTitanium]

I see a lot of fine, black dust particles. Slipper pads are white. The dust particles are most likely from wear created from friction between the spur and pinion gears.

The stock Arrma motor pinion gear is made of Chinesium (crap metal from China). I say that the pinion is the problem as I have yet to see the 4s metal spur gear wear.

I cannot see it in the first picture but I suspect that the pinion is badly worn and needs to be replaced. Provide a photo of the pinion gear from the side view (contact area).

 

[MrTitanium]

Why did you create a double post?

https://www.arrmaforum.com/threads/kraton-4s-differential-issue.68411/#post-1046570

 

[gotnitro]

Whoap hey now..

Got to get moved or deleted immediately

 

[MrTitanium]

Whoap hey now..

Got to get moved or deleted immediately

 

[theapplepilot]

I see a lot of fine, black dust particles. Slipper pads are white. The dust particles are most likely from wear created from friction between the spur and pinion gears.

The stock Arrma motor pinion gear is made of Chinesium (crap metal from China). I say that the pinion is the problem as I have yet to see the 4s metal spur gear wear.

I cannot see it in the first picture but I suspect that the pinion is badly worn and needs to be replaced. Provide a photo of the pinion gear from the side view (contact area).

Here you are

 

[gotnitro]

Here you are

View attachment 346516

View attachment 346517

Nice!

Just add some shock oil and you’ll have a nice gear salad. Replace both obviously.

 

[slick2500]

.

 

[theapplepilot]

Nice!

Just add some shock oil and you’ll have a nice gear salad. Replace both obviously

With stock or do you recommend something better?

 

[RCbuzz]

Whoa! How is that still running? Replace that pinion at a minimum.

Spur doesn't look half bad. Those spurs are quite expensive, I think JRC has stock pinions for a couple bucks.

Might want to consider sealing your power module. Motor bearings will suffer from the debris.

 

[gotnitro]

With stock or do you recommend something better?

That usually happens when you’re not maintaining your rig, making sure the motor mount bolts are secure etc. Whilst you are in there, might as well replace both.

 

[theapplepilot]

Whoa! How is that still running? Replace that pinion at a minimum.

Spur doesn't look half bad. Those spurs are quite expensive, I think JRC has stock pinions for a couple bucks.

Yeah Ill buy the parts thanks to everyone for the help

View attachment 346525

That usually happens when you’re not maintaining your rig, making sure the motor mount bolts are secure etc. Whilst you are in there, might as well replace both.

What maintenance am I not doing. Just the usual clean up? Do I need some special oil? Sorry for all these questions but I’m new to all this.