Lost rear wheel drive...

[Hubdy]

Good afternoon, so I was doing some casual bashing on the back of the store parking lot. Some time into it I heard some "crunching" noise when turning upder power. So I kept on driving it because I thought that maybe body of the car is rubbing on something and a few minutes later it became a front wheel drive car. I'm pretty sure that the issue is with the rear diff (haven't taken it apart yet.) What usually goes bad/weak on these? Any parts to upgrade while I'm at it?

*It's a V2 Exb rtr kraton running a 12s set up.

 

[Moirae]

Check rear dogbone at the diff cup. I bet you lost the pin in the dogbone

 

[Diem Turner]

Check rear dogbone at the diff cup. I bet you lost the pin in the dogbone

^^This. Might be worth checking the grub screw of the input cup on the rear diff too while you're rummaging around in that area.

 

[Moirae]

^^This. Might be worth checking the grub screw of the input cup on the rear diff too while you're rummaging around in that area.

Welcome back broham!!

 

[Hubdy]

I'll try to check it out later on today, thank you
Should I add some shims? And if so how do I know if it needs any?

 

[Hubdy]

So yes the diff is bad lol. Now the question I got, is running thicker diff fluid will make it more durable/longevity increase or not? I think the stock diff fluid is 100k.

Will arrma warranty cover it?

 

[blobcomm]

Mine has grenaded the same was twice now anyone know how to get the gears to not eat eachother thicker fluid ,shims, aluminum diff cup?

 

[Hubdy]

Yes, please help #save12skraton

 

[Hammer Down]

Will arrma warranty cover it?

Probably, so long as it’s within the 2yr warranty period and you have your receipt.
Is the cup cracked?

 

[Hubdy]

Probably, so long as it’s within the 2yr warranty period and you have your receipt.
Is the cup cracked?

The cup is not cracked. And I'm not sure about the paper copy but I should be able to find the credit card invoice (it's only about 4 months old)

Mine has grenaded the same was twice now anyone know how to get the gears to not eat eachother thicker fluid ,shims, aluminum diff cup?

Interested as well

 

[blobcomm]

no the cup is not cracked on mine but this is the second diff that has gone bad and I think I only had 3 packs through it rebuilt to factory spec I’m thinking thicker fluid my though behind that is less rotation on the internal gears therefor less wear but might sacrifice some turning ability and yes I am talking about the rear diff it’s 100k factory

 

[Hubdy]

no the cup is not cracked on mine but this is the second diff that has gone bad and I think I only had 3 packs through it rebuilt to factory spec I’m thinking thicker fluid my though behind that is less rotation on the internal gears therefor less wear but might sacrifice some turning ability and yes I am talking about the rear diff it’s 100k factory

Do you know if adding thicked fluid actually relieves the stress off the diff?

 

[KnowAir]

Wow, that is an ugly diff you've got there!! Have you ever had it apart before now? You said 4 months old, correct? It should fall under warranty I would think. I wouldn't advertise that you're running 12s in it though. They may try and use that against you. One thing I have found with rtr diffs routinely is loose screws holding the ring gear to the cup, which of course creates all kinds of tolerance issues..and fluid loss. Your's looks to have a decent amount of fluid though. The dark fluid streaks are interesting. I suggest making a warranty claim, worth a shot. What motor esc combo are you running out of curiosity?

 

[Hubdy]

Wow, that is an ugly diff you've got there!! Have you ever had it apart before now? You said 4 months old, correct? It should fall under warranty I would think. I wouldn't advertise that you're running 12s in it though. They may try and use that against you. One thing I have found with rtr diffs routinely is loose screws holding the ring gear to the cup, which of course creates all kinds of tolerance issues..and fluid loss. Your's looks to have a decent amount of fluid though. The dark fluid streaks are interesting. I suggest making a warranty claim, worth a shot. What motor esc combo are you running out of curiosity?

Yeah I'll definitely won't mention to the warranty people that I run at 12s setup LOL. Max5 g2 and castle 2028 800kv

 

[KnowAir]

Yeah I'll definitely won't mention to the warranty people that I run at 12s setup LOL. Max5 g2 and castle 2028 800kv

I'd just be weary. Not saying it will or won't matter. IDK. Good luck brother.

 

[Hubdy]

I'd just be weary. Not saying it will or won't matter. IDK. Good luck brother.

I mean it is what it is. If they cover it I would appreciate it.

 

[RCbuzz]

I feel like 12S would be one of those "warranty void" clauses . Luckily the diff's are not too expensive from a kit breaker:

https://www.ebay.com/itm/383471609263?hash=item5948b065

or just the sun/satellite gears: https://www.ebay.com/itm/194485538405

 

[Hubdy]

Arrma just got back to me. They will be sending me a new diff. And again, much appreciated .
If it happens again I won't try to use the warranty again. Instead will look for a tougher diff set up.