Is this diff leak or just some factory oil?

[Hotwheel85]

Hello.

Since it have been rainy days and cold i have only had two runs with my kraton 8s.
When i unboxed it for a week ago i noticed some oil outside the front diff left side, but it was very little. After first run i checked it again and it seems fine.
Now after been stored for around 5 days i see some oil again.

It’s nothing on the floor, just on the driveshaft the oil is very sticky and noticible.

Could this be some oil after it mounted togehter and it would be gone? Or could it need new gasket on the internal diff?

Wanted to ask here before i bother the store with some warranty questions.

Here is a few pics.

Thanks for helping me solving this.

 

[DoNoHarm]

That isn’t right... crack the diffcase open and check out the diff itself... if area surrounding the diff is full of oil, or the outside of the diff is covered in it, it’s definitely leaking.

 

[Hotwheel85]

That isn’t right... crack the diffcase open and check out the diff itself... if area surrounding the diff is full of oil, or the outside of the diff is covered in it, it’s definitely leaking.

Yes going to open it later tonight, do i need a new gasket after opening it, or could i just mount it together and hope it stop leaking?
And the diff house inside should be full with oil right up to the edge of the housing?

 

[Surchaufeur]

Your the second one who had this issue i think there is a defect in the factory assembly. Call horizon and they will send you a remplacement if the seals are busted
And yes the diffs should be almost full

 

[Hotwheel85]

Looks messy, would open and see how much is left there

 

[Surchaufeur]

Looks messy, would open and see how much is left there

I think its leaking towards the right side of the output diff cup

 

[Hotwheel85]

it’s almost empty but the gear seems covered in oil if i spin them around, and i cant understand when it could leak out that much. Since i managed this since start.
Question is if the diff is got weaker/damaged by driven in this condition? Would a new gasket and oil help or should i request a new diff?

Didnt drived it much maby 10 min x2 carefully around testing stuff get to learn driving it.
Would try to call them yes. But i doubt they would help me since i live in Europe (Norway) most probably they ask me to contact my LHS?

 

[slick2500]

Your the second one who had this issue i think there is a defect in the factory assembly. Call horizon and they will send you a remplacement if the seals are busted
And yes the diffs should be almost full

No the diffs should be filled up to the cross pins if you fill it much more than that it's going to blow out the seals and leak again.

 

[Hotwheel85]

Good to know! Then it’s not completly empty it seems but it do need more oil, cant see any issue with the gasket either, and all the screws was tight. So why do it leak is a good question.

Btw how do one remove the steel diff outdrive cup on the diff? I opened it with the bearing and the driveshaft cups mounted to it. Must we open the diff to loosen it from inside?

 

[slick2500]

Good to know! Then it’s not completly empty it seems but it do need more oil, cant see any issue with the gasket either, and all the screws was tight. So why do it leak is a good question.

Btw how do one remove the steel diff outdrive cup on the diff? I opened it with the bearing and the driveshaft cups mounted to it. Must we open the diff to loosen it from inside?

As far as it leaking initially it was probably overfilled from the factory but it could have just been assembled incorrectly no way to really tell. If it was me I would probably replace the orings and the gasket just incase.

As far as taking that apart I'm not sure as I am not familiar with the 8s models @bicketybam is the man to talk to.

 

[Hotwheel85]

Yes not easy to know, but out from the pics the gears should be just fine since it’s not completly empty?

In my case the only Arrma dealer haven't got spare parts yet. And if they order tomorrow it could take 1-3 weeks before they get it, then a couple days to ship it to me. (Want to fix it asap)

If i don't need to worry about the front diff gears been running like this i just order a bottle of diff fluid and hope it’s not leaking, and i will also ask them to order a gasket kit for me so i change it out if it start leaking.

Rest of the truck seems fine, it’s not easy to see the front of the center diff though.
It was very easy to get the diff out! Took me maby 5 min only. Im used to spend a lot of time to get the diffs out

 

[Surchaufeur]

the seal on one side of the diff cup is leaking
Thats what i see

 

[jondilly1974]

If you’re in a hurry, grab some rtv sealant from an auto parts store to get you by until you can get a new gasket.

 

[Jimbobjr]

I had the same deal. Called horizon and 3 days later these were in the mail box. Sometimes if a diff screw is too tight it deforms the top of the diff cup. The threads are pulling up through the hole deforming the edge of the cup like a crater. Sometimes it’s so bad you need to use a wide flat file to make it flat again.

 

[Hotwheel85]

Would check if the diff cup is flat, is this part number ara 310936 the only gasket for the diff like the one you got in the mail?

O rings is ara716028
It could leak from left side o ring and not gasket maby? Since the leak is on left side on the diff.

 

[Hotwheel85]

Adding a new pics where i marked with red where the leak is, it could indicate that it’s a o ring that leak? Is it possible to do anything wrong when one insert the o ring on the factory? Or it could have been some damage

@Jimbobjr they only sent you the diff house gasket and not the o rings?

 

[Hotwheel85]

What type of grease should i add to the pinion and ring gear?

Can i use CRC universal grease that is litiumbased?
It wasnt much grease from factory, could be a good idea to open all the diff and add more?

 

[Surchaufeur]

What type of grease should i add to the pinion and ring gear?

Can i use CRC universal grease that is litiumbased?
It wasnt much grease from factory, could be a good idea to open all the diff and add more?

Marine grease multi purpose grease is what i use
My multi purpose grease is the same color as the stock grease.
Of what i can see there is enough grease but its uo to you if you want to add more.

Would check if the diff cup is flat, is this part number ara 310936 the only gasket for the diff like the one you got in the mail?

O rings is ara716028
It could leak from left side o ring and not gasket maby? Since the leak is on left side on the diff.

If its leak on one side its definetly a bad seal

 

[Hotwheel85]

I got the diff appart and inspected everything. Seems like it was mounted right, and i cant see any sign of damage to both o rings or gasket.
Only thing i noticed was little dirt between the o ring and diff house (q tip got black after cleaning there)

And around the holes on the diff house it’s not completly flat after the factory added the threaded holes.

Think i just order grease and diff oil, mount it together and hope it stop leaking.

Otherwise i think i should get new o rings, gasket and diff house on the warranty to solve it.

Another question:
How far in should i screw the grub screw on the diff housing?

 

[Clubin]

Flush on the outside.