Kronos XTR Center Diff Issue

[BrettOlbrys]

I have never done diff service before, so I have a few questions. I had to remove the center diff because I THOUGHT I stripped the gears because my 2022 Kronos XTR wheels froze and there were metal shavings in the chassis. But after taking it apart, it wasn't the gears at all.

Apparently, two bevel gear screws became loose and started eating into the motor mount, and essentially started to grind it down (pictures attached).

1) Based on the photos, do I need to replace the motor mount?

Since I had the center diff out, I figured I would open it up to check the fluid level. Since I have never opened a diff before, I attached some photos for my questions.

2) Is the diff lubricant supposed to be dark or more clear like fresh engine oil?

3) Does the amount of oil look good?

Last issue, when I was removing the center diff motor mount and parts, a little silicone "something" was sitting in the bottom of my chassis.

4) Any idea what it is, and should there be two or just the one?

Thanks

Brett

Also, when replacing the diff oil, do you disassemble the entire diff and clean off every single gear and part of the old oil before adding the new oil?

 

[The Stig]

1. Change it. Erik van Ravenstein on FB has some nice 7075 ones or get 7075 corally one.

2+3 clean it and change it with more oil. It is open anyway. Take all the parts out to be cleaned.

4. That thing goes in the Swiss steel drive cup. It is a piece of fuel hose. Stops the drive train to moving to much in the xups

Hope it helps bro. Oh and if you close the diff. Use some blue Locktide on the screws. Alu on alu needs Locktide

 

[Horatio]

Yeah, your motor mount is now decidedly second hand! But it should still function alright.

Most of your oil has leaked out. You need to refill your diff with 30-100k diff oil. Your diff should also have a paper gasket between the case and the spur.

 

[BrettOlbrys]

Thanks for the info. I will let you both know how things turn out.

 

[Horatio]

Thanks for the info. I will let you both know how things turn out.

If it's any consolation - mine started to come loose and my diff lost oil. I noticed before any damage occurred.

The screws 100% need blue loctite to stop them backing out. Looking at the amount of grinding that's occured, you might wanna change the screws.

 

[BrettOlbrys]

If it's any consolation - mine started to come loose and my diff lost oil. I noticed before any damage occurred.

The screws 100% need blue loctite to stop them backing out. Looking at the amount of grinding that's occured, you might wanna change the screws.

I'm definitely changing the screws and will apply the loctite. I didn't do it in the first place because I never opened up the diffs, so there was no reason for me to know the screws would back out.

 

[The Stig]

I'm definitely changing the screws and will apply the loctite. I didn't do it in the first place because I never opened up the diffs, so there was no reason for me to know the screws would back out.

Normally it should have some on it from the factory. But.......quality control

 

[Jeffwazz]

Yep, happened to my centre diff as well, but all 4 had backed out just enough to spin the diff syrup out and coat the chassis in black gunge. Took a while to clean it up, but it does make the black plastics look nice.
No such issues since I rebuilt it properly tho

 

[Horatio]

I'm definitely changing the screws and will apply the loctite. I didn't do it in the first place because I never opened up the diffs, so there was no reason for me to know the screws would back out.

100% not your fault. You didn't build the diff to begin with.

Perhaps you'll notice sooner next time.

 

[VaporTrail]

It might just be the angle of the pic, but it appears to me that the holes may have been rounded out on the diff case. You might need to change that out. I agree with Horatio; your motor mount should function just fine, but replacing it would be a better option. Low diff fluid from the factory seems to be a common enough occurrence that most here will recommend to double check the fluid levels just to be on the safe side. Speaking of diff fluid, yours definitely looks like it would not mind a fresh batch.

For my diffs I usually add some loctite, but on the ones where the diff fluid has leaked into the screw holes, I just tighten them down a little more than spec. Be careful not to crush the gasket. Also a good idea to do a visual inspection before the run, just to make sure everything is nice and tight.

 

[KnowAir]

I had the same happen to my center diff.. screw backed out until it ate into the motor mount, caught, bound up right tight she did!!
I managed to get the affected screw out, cleaned the diff cup as best I could, refilled, threadlocker, reinstalled. Hasn't happened again. The motor mount looks fine to me.
What doesn't help is that plastic gear cover, can't see what's going in in there very well. I hacked the extended piece off so I can more easily do a visual inspection for the diff screws.
Good luck brother.

 

[BrettOlbrys]

I ordered a bunch of new and hardened parts from Erik van Ravenstein (https://www.facebook.com/erik.vanravenstein?mibextid=LQQJ4d), but will probably reuse the motor mount because it is scuffed up, not damaged.

 

[morrjr71]

I have 7075 hinge pin mounts and center diff inserts from Erik on my Muraco. His stuff is of the highest quality and is fairly priced.

 

[VaporTrail]

When I get a little more disposable income, I'd like to get those 7075 hinge pins mounts

 

[BrettOlbrys]

I want to use the new center diff that I purchased, but for some reason, I cannot the drive cup and bearings from these gears. I don't want to force them apart, but they do not pull apart with just my fingers unless I'm supposed to use some force. Is there something holding all of this together or should they easily slide apart?

 

[Horatio]

I want to use the new center diff that I purchased, but for some reason, I cannot the drive cup and bearings from these gears. I don't want to force them apart, but they do not pull apart with just my fingers unless I'm supposed to use some force. Is there something holding all of this together or should they easily slide apart?
View attachment 5599

Perhaps the pin is a little wedged on the planetary diff gears (the bigger ones) but they should come off easily - you just need to slide that pin out. C-00180-205.

Nothing there that should require anything other than a delicate touch.

 

[VaporTrail]

I agree with Horatio. It shouldn't be too difficult to remove, but sometimes they can be stubborn. Get a pair of flat tip screw drivers and gently pry on opposite sides. That should work.

 

[KnowAir]

Yes, they should slide right off. I use needle nose to grab the outer surface and pull straight off. The grease/oil is likely creating some suction thats holding the gear on.. which BTW can be a blessing while assembling too. A dab of silicone grease or oil to hold things in place during assembly sure makes life easier. Feel free to check out some YT vids on the matter as well. If I'm not mistaken, there may even be a video by Dr Corally that covers the subject. Take ur time brother. Shout out if you're still struggling.

 

[BrettOlbrys]

Has anyone bought the center diff from Erik van Ravenstein for the Kronos XTR 2022? I'm trying to reassemble this new diff from the stock diff, and I'm having trouble figuring a couple of things out. Does anyone have any step-by-step instructions on how to reassemble with this diff or if one of you was available to help guide me personally, I would be grateful.

 

[Horatio]

Has anyone bought the center diff from Erik van Ravenstein for the Kronos XTR 2022? I'm trying to reassemble this new diff from the stock diff, and I'm having trouble figuring a couple of things out. Does anyone have any step-by-step instructions on how to reassemble with this diff or if one of you was available to help guide me personally, I would be grateful.

I'm pretty sure The Stig and Angry Section 8 has used these. Ultimately, the diff uses all the same internals, so unless I'm overlooking something - it should be the same as rebuilding a stock diff.

Oh - and by the way - you're welcome.