I'm aware there are other threads for people who have noted blown rear diffs on their Kraton EXB. I'll share my experience, what caused it to happen and note the potential fix based on what Horizon Hobby told me, as well as the other gracious forum members who have shared their experiences and findings.
Motor: Castle 1717 1650kv
ESC: Mamba Monster X 8S
Pinion: Tekno 23t
Spur Gear: Factory
Battery: 2x Spektrum 3s 100c
Voltage: 7.5V
Tires: Pro-line Bandlands MX38 3.8 (Belted)
Before I ever ran the car I took apart the front, center, and rear diffs to add in Hudy Ultimate Silicone and inspect everything. Thanks to all the forum members who have created threads on the issues with the EXB; it helped me prepare for what could happen with the rear diff.
My Diff Fluid Setup
Front: 50,000cst
Center: 300,000cst (200k wasn't in stock)
Rear: 30,000cst (20k wasn't in stock)
Conditions When The Diff Was Blown
Temperature: 74 degrees fahrenheit
Weather: Clear
Riding surface: Wet grass and Pavement
Riding style: Non-aggressive (feathering the throttle)
As I was riding, I started to hear a clanking noise and so I immediately drove the car into the garage and took apart the diff. Once again, thanks to everyone on this forum posting about their EXB issues, I was able to quickly identify the problem area. As you'll see in the images below, the sun gears cracked and some have also worn down.
I have reached out to Horizon and they are sending me all new diff parts including the LSD plates (ARA310984) that are in the front and center diffs. They said that these plates will resolve the issue. (TBD)
In the meantime, I have won an auction on eBay for a brand new EXB diff. With shipping the grand total was $89.99. To note - I'm super thankful my wife doesn't ask too many questions so long as I'm happy . I realized I was raped for paying that much... but I want to get back to bashing and enjoying my car. If it's only $89.99 between me enjoying my car or sitting it on a self, I'd rather shell out the dough.
There isn't a price for the kool-aid smile this car gives me when I'm bashing it. ?
**UPDATED September 9th, 2020**
So good news - I dissembled the center diff I purchased at a ridiculous price on eBay ?. What I took from it to rebuild my rear diff was the LSD plates, sun gears, planet gears, and one shim. I took one of the thinner (thinest one) shims from that donor diff and put it on the ring gear side of my rear diff; I tried to add one to the diff cup side as well, but it was extremely tight. (that's what he said) ?
Lastly, I filled the diff back up with Hudy 30,000cst Ultimate Silicone Oil.
I did a "light" bashing session last night and it everything was running well. I was using two 3s 100c Spektrum batteries at 7.5V. I'm hoping this can be consider a chalked up issue, but only time will tell. Hopefully, this information helps someone dealing with similar issues. ?
Motor: Castle 1717 1650kv
ESC: Mamba Monster X 8S
Pinion: Tekno 23t
Spur Gear: Factory
Battery: 2x Spektrum 3s 100c
Voltage: 7.5V
Tires: Pro-line Bandlands MX38 3.8 (Belted)
Before I ever ran the car I took apart the front, center, and rear diffs to add in Hudy Ultimate Silicone and inspect everything. Thanks to all the forum members who have created threads on the issues with the EXB; it helped me prepare for what could happen with the rear diff.
My Diff Fluid Setup
Front: 50,000cst
Center: 300,000cst (200k wasn't in stock)
Rear: 30,000cst (20k wasn't in stock)
Conditions When The Diff Was Blown
Temperature: 74 degrees fahrenheit
Weather: Clear
Riding surface: Wet grass and Pavement
Riding style: Non-aggressive (feathering the throttle)
As I was riding, I started to hear a clanking noise and so I immediately drove the car into the garage and took apart the diff. Once again, thanks to everyone on this forum posting about their EXB issues, I was able to quickly identify the problem area. As you'll see in the images below, the sun gears cracked and some have also worn down.
I have reached out to Horizon and they are sending me all new diff parts including the LSD plates (ARA310984) that are in the front and center diffs. They said that these plates will resolve the issue. (TBD)
In the meantime, I have won an auction on eBay for a brand new EXB diff. With shipping the grand total was $89.99. To note - I'm super thankful my wife doesn't ask too many questions so long as I'm happy . I realized I was raped for paying that much... but I want to get back to bashing and enjoying my car. If it's only $89.99 between me enjoying my car or sitting it on a self, I'd rather shell out the dough.
There isn't a price for the kool-aid smile this car gives me when I'm bashing it. ?
**UPDATED September 9th, 2020**
So good news - I dissembled the center diff I purchased at a ridiculous price on eBay ?. What I took from it to rebuild my rear diff was the LSD plates, sun gears, planet gears, and one shim. I took one of the thinner (thinest one) shims from that donor diff and put it on the ring gear side of my rear diff; I tried to add one to the diff cup side as well, but it was extremely tight. (that's what he said) ?
Lastly, I filled the diff back up with Hudy 30,000cst Ultimate Silicone Oil.
I did a "light" bashing session last night and it everything was running well. I was using two 3s 100c Spektrum batteries at 7.5V. I'm hoping this can be consider a chalked up issue, but only time will tell. Hopefully, this information helps someone dealing with similar issues. ?
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