Kraton Kinda pissed. Venting.

[Xjeepguy]

So I got the new Kraton 4s V2 last week, and the weather has sucked until today, so I took it and the XRT out for a quick bash.

I ran the truck for 3 minutes.

It was making a loud noise, and the only reason I ran it that long was to try to figure out where it was coming from. So I took it home, checked the center diff, it was fine. Opened up the front bulkhead and found this.

Barely any grease. Upon further inspection, I found this.

That’s from 3 minutes of driving. And there’s definitely a rough spot in the rotation of the ring gear.

Yes. I know. I should have checked it before I took it out. I normally do. But I took the chance one time… Lesson learned. But this isn’t why I’m pissed. I’m pissed because now I have to go through Horizon’s warranty process and it’ll likely be 2 weeks before I can enjoy my truck. Yes, I could just run it sounding like a blender on purée until the parts get here (if they approve it), but that just doesn’t feel right. I did shim the diff and added some of that blue awesomeness that came with my Vanquish Phoenix kit. (Best grease ever btw. ) so maybe I’ll take it for a spin tomorrow and see if she’s any quieter after I check the rear diff. Grrrrr.

First world problems.

 

[Surchaufeur]

Whats the bump on the gear? The little line? If you run plastic yokes there will always be some hard spots. The aluminum ones you can shim them. The plastic gear when new always had binding for wearing down to mesh correctly.

 

[PrerunninF150]

Am I missing something? I have a 6s so I don't know what the 4s are supposed to look like but they look fine to me.

 

[Hector_Fisher]

Yeah I'd be fast to ping HH to have them make things right. While we all know its wise to tear these things open before running, there's no explicit wording in the manual or on the box that says it needs maintenance before running. So it's on their bad QC for not taking the time to ensure that people won't use the warranty.

If they don't come through though, I'd still be tempted to keep running those gears. Lube em up and send em. The scoring may potentially "rub" off with more runs, so maybe in a few packs I'd break it open, degrease and clean, and reapply. Hopefully HH gets it sorted out for you man

 

[jkflow]

FYI, that is plenty of grease. We all just typically overdo it by piling it on but serves no real purpose.

Honestly, I don't even see anything wrong but could be the picture.

 

[RCbuzz]

So I got the new Kraton 4s V2 last week, and the weather has sucked until today, so I took it and the XRT out for a quick bash.

I ran the truck for 3 minutes.

It was making a loud noise, and the only reason I ran it that long was to try to figure out where it was coming from. So I took it home, checked the center diff, it was fine. Opened up the front bulkhead and found this.

View attachment 340738

Barely any grease. Upon further inspection, I found this.

View attachment 340739

That’s from 3 minutes of driving. And there’s definitely a rough spot in the rotation of the ring gear.

Yes. I know. I should have checked it before I took it out. I normally do. But I took the chance one time… Lesson learned. But this isn’t why I’m pissed. I’m pissed because now I have to go through Horizon’s warranty process and it’ll likely be 2 weeks before I can enjoy my truck. Yes, I could just run it sounding like a blender on purée until the parts get here (if they approve it), but that just doesn’t feel right. I did shim the diff and added some of that blue awesomeness that came with my Vanquish Phoenix kit. (Best grease ever btw. ) so maybe I’ll take it for a spin tomorrow and see if she’s any quieter after I check the rear diff. Grrrrr.

First world problems.

Oof, that does not look good for 3minutes! Is it because of an imperfection on the ring gear? Interesting that the input is wearing just in that one spot all the way around.

Maybe it will work itself out on another run

 

[Bustedaw11]

Am I missing something? I have a 6s so I don't know what the 4s are supposed to look like but they look fine to me.

No grease.... and if you look closely at the pinions teeth you can see they already have quite a bit of wear.

As much as I hate to admit it this is 1 of the things that I loved traxass for... I've owned TONS of thier vehicles over 30 years and I cannot remember a single time I had an issue out of the box.. Thier QC is top notch in my eyes. I wish Arrma would realize how important that is... blown esc's, blown servos' empty diffs and poorly shimmed diffs are all but to common with them.

Being experienced I've come to learn to check things over when I buy a pre-built rig.... but it really bothers me to think about all these new to newer folks that drop these huge amounts of cash for a rtr only to have them break or trash themselves almost immediately because they didn't know better to check them out.

 

[Surchaufeur]

No grease.... and if you look closely at the pinions teeth you can see they already have quite a bit of wear.

As much as I hate to admit it this is 1 of the things that I loved traxass for... I've owned TONS of thier vehicles over 30 years and I cannot remember a single time I had an issue out of the box.. Thier QC is top notch in my eyes. I wish Arrma would realize how important that is... blown esc's, blown servos' empty diffs and poorly shimmed diffs are all but to common with them.

Being experienced I've come to learn to check things over when I buy a pre-built rig.... but it really bothers me to think about all these new to newer folks that drop these huge amounts of cash for a rtr only to have them break or trash themselves almost immediately because they didn't know better to check them out.

There is grease look the the crown gear.. theres bloaches of it. Not saying its enough grease. But the grease they use is translucent and it can seem like theres nothing to the naked eye. Traxxas sells you escs with no fans that had an history of catching fire. Servos that strip because they are plastic geared even up to their 6s lineup. Adding more grease wont make the sound go away i can guarantee you that. most of the grease flies offat the first trigger pull Leaving a tiny film only coating the gears and that is all the grease you will have. We people like to add way too much grease. A full turn with a syringe of grease while turning the sun gear manualy is enough grease. It could look to have none because 1 you ran it, 2 the grease is translucent. Lot of us like to use all purpose grease or lucas n tacky who is red in colour who turns slightly wine red under use

 

[Bustedaw11]

There is grease look the the crown gear.. theres bloaches of it. Not saying its enough grease. But the grease they use is translucent and it can seem like theres nothing to the naked eye. Traxxas sells you escs with no fans that had an history of catching fire. Servos that strip because they are plastic geared even up to their 6s lineup. Adding more grease wont make the sound go away i can guarantee you that. most of the grease flies offat the first trigger pull Leaving a tiny film only coating the gears and that is all the grease you will have. We people like to add way too much grease. A full turn with a syringe of grease while turning the sun gear manualy is enough grease. It could look to have none because 1 you ran it, 2 the grease is translucent. Lot of us like to use all purpose grease or lucas n tacky who is red in colour who turns slightly wine red under use

You simply cannot compare the amount of issues between these two companies.

Which has the better QC? Traxxas. Just a simple fact. Why I said I wish Arrma would get on thier Qc and stop letting them win in that department.
I'd much rather see Arrma succeed then the other.....

That was kinda my point..

 

[Xjeepguy]

Whats the bump on the gear? The little line? If you run plastic yokes there will always be some hard spots. The aluminum ones you can shim them. The plastic gear when new always had binding for wearing down to mesh correctly.

That’s the edge of the wear from the ring gear. Cracked open my 4sMojo to compare last night, and after several batteries, it’s nowhere near this worn.
The issue may not be grease related, there are molded parts that set the gear mesh that may be off slightly, and maybe it’ll self clearance, but I’m just mostly annoyed that I have two trucks here that have the exact same drivetrain, one sounds buttery smooth, the other sounds like a 2 stroke dirtbike with an FMF on it. Weather permitting, I’ll take it out this evening and see if it’s any better. If it’s not, I’ll try to get some video of the sound for you guys.

 

[Bustedaw11]

That’s the edge of the wear from the ring gear. Cracked open my 4sMojo to compare last night, and after several batteries, it’s nowhere near this worn.
The issue may not be grease related, there are molded parts that set the gear mesh that may be off slightly, and maybe it’ll self clearance, but I’m just mostly annoyed that I have two trucks here that have the exact same drivetrain, one sounds buttery smooth, the other sounds like a 2 stroke dirtbike with an FMF on it. Weather permitting, I’ll take it out this evening and see if it’s any better. If it’s not, I’ll try to get some video of the sound for you guys.

You could always try and clearance the back side of the diff cage to open the mesh a tiny bit. It clear the mesh is to tight.
That or just run it and let it do it itself. That'll probably produce a little metal in the grease though.

 

[gotnitro]

I don't think many people know exactly how fast these gears turn.

The more grease you use, the more grease gets FLICKED off the gears on one singular throttle stab and is now stuck to your internal diff case not even touching any gear.

Internal gears need a light coating of grease that you can't even see, that's it.

 

[KnowAir]

Looks like a shimming issue to me? The wear on the pinion suggests the ring and pinion aren't fully engaged. Of course with mass produced plastic housings there will always be some potential for tolerance issues. Possible that the ring gear also has imperfections for sure too..
As to the grease, I agree with @jkflow , a dab will do it..most put waay too much in there from what I've seen. All that is needed is contained on the surface of the gears themselves. All the globbed grease isn't doing anything other than retaining whatever dirt makes it's way into the housing IMO.
I'd submit a claim, shim, carry on. They will quiet down, although life span is probably compromised.
My Xmaxx was noisey as heck when new out of the box..after a few packs, say 6-8, it quieted down.. that was 2 years ago. Original spur gear is still fine, pinion wore out but, that's fair.

I don't think many people know exactly how fast these gears turn.

The more grease you use, the more grease gets FLICKED off the gears on one singular throttle stab and is now stuck to your internal diff case not even touching any gear.

Internal gears need a light coating of grease that you can't even see, that's it.

+1
FWIW..when I have to open a gearbox, there's always some excess grease globbed up somewhere inside the housing. I take a clean flat blade screwdriver and scrape it out and discard it..

 

[Surchaufeur]

Rule of thumb for me is i always put whatever hold my gearmesh in the rear in aluminum. So my gears wont strip because of plastic flex or have unheaven wear because of it. The front is the diff with the least stress of all differentials in the truck

 

[RCbuzz]

Rule of thumb for me is i always put whatever hold my gearmesh in the rear in aluminum. So my gears wont strip because of plastic flex or have unheaven wear because of it. The front is the diff with the least stress of all differentials in the truck

This. It would be cool to see via camera how much the plastic yoke flexes under the right situations. I am guessing it's more than we think.

Based on the plastic diff failures we have had (3s line) it sure seems like the gear mesh was off right before failure..

 

[Surchaufeur]

This. It would be cool to see via camera how much the plastic yoke flexes under the right situations. I am guessing it's more than we think.

Based on the plastic diff failures we have had (3s line) it sure seems like the gear mesh was off right before failure..

S gears would strip on my k4s every 5-7 packs or so Vs never once i switched with the aluminum yokes in the rear

 

[phm14]

There is grease look the the crown gear.. theres bloaches of it. Not saying its enough grease. But the grease they use is translucent and it can seem like theres nothing to the naked eye. Traxxas sells you escs with no fans that had an history of catching fire. Servos that strip because they are plastic geared even up to their 6s lineup. Adding more grease wont make the sound go away i can guarantee you that. most of the grease flies offat the first trigger pull Leaving a tiny film only coating the gears and that is all the grease you will have. We people like to add way too much grease. A full turn with a syringe of grease while turning the sun gear manualy is enough grease. It could look to have none because 1 you ran it, 2 the grease is translucent. Lot of us like to use all purpose grease or lucas n tacky who is red in colour who turns slightly wine red under use

Lucas Red & Tacky is good stuff. Is that gap at the inner bearing race normal? The drive cups I can get fingers on, in my new K6 EXB diffs, feel tighter than that looks.
I bought the K4s 2.5, to check out, while I waited for my pre-ordered 6s EXB. Turns out, I got the 6s, within days of the 4s. There's a short thread here, where I do a brief comparison, after running both, and why I decided to sell the 4s, and keep the 6s: https://www.arrmaforum.com/threads/arrma-kraton-4s-v2-5.67329/

 

[Xjeepguy]

I heard back from HH yesterday, and after reviewing these pics, they’re sending me a complete diff and pinion. I’m also ordering aluminum yokes, a better servo, and a better servo saver. The steering was lethargic at best the short time I got to run it. I don’t plan to sink a ton of money into this one, because the main reason I bought it was so that peeps with little to no experience with RC that come to visit could run it.

 

[phm14]

I heard back from HH yesterday, and after reviewing these pics, they’re sending me a complete diff and pinion. I’m also ordering aluminum yokes, a better servo, and a better servo saver. The steering was lethargic at best the short time I got to run it. I don’t plan to sink a ton of money into this one, because the main reason I bought it was so that peeps with little to no experience with RC that come to visit could run it.

I've got a beat up Rival MT10, for that.

 

[Xjeepguy]

I've got a beat up Rival MT10, for that.

I have an MT10 that I originally bought for that purpose, but I liked it so much that I began the upgrade process, and now it’s way too quick for someone new to the hobby lol. I love that thing lol.