Kraton KRATON EXB 6S

chazzz

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I've got as Kraton 6S EXB that I am working on.

- EBX Roller
- Spektrum 150a ESC
- Spectrum Firma 2050Kv
- Spektrum SR315 receiver
- D951TW servo

Going to clean it up and then work on a nasty click coming from the center diff.

Any thoughts, suggestions or questions are welcome.

Thank you,


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parcou

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I've got as Kraton 6S EXB that I am working on.

- EBX Roller
- Spektrum 150a ESC
- Spectrum Firma 2050Kv
- Spektrum SR315 receiver
- D951TW servo

Going to clean it up and then work on a nasty click coming from the center diff.

Any thoughts, suggestions or questions are welcome.

Thank you,


View attachment 269470

View attachment 269472

View attachment 269475

View attachment 269474

View attachment 269473

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View attachment 269477

View attachment 269471

Welcome!

Nice project. Have fun with it. Kraton EXB check those diffs being LSD diffs some like and some do not like the LSDs. Great idea to get inside and check and make sure those plates and washers in the diffs are good.

I see some rust, so look it over well, especially in areas you cannot see where water can go. Get a bearing kit to be ready, especially the wheels, steering bellhousing, and diffs.

Enjoy (y)
 

chazzz

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Arrma RC's
  1. Kraton EXB
Welcome!

Nice project. Have fun with it. Kraton EXB check those diffs being LSD diffs some like and some do not like the LSDs. Great idea to get inside and check and make sure those plates and washers in the diffs are good.

I see some rust, so look it over well, especially in areas you cannot see where water can go. Get a bearing kit to be ready, especially the wheels, steering bellhousing, and diffs.

Enjoy (y)
Copy that. Any tips on rust removal best practice?

Thanks,
 

Diem Turner

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Welcome aboard! Nice ride :)

I just bought a used EXB myself in December so, we were/are sitting in the same boat. For rust removal, you can use electrolysis to plate the metal, but that's a bit more involved. Just grab a wire brush and after you've given them a scrubbing, coat them with a little WD40.

Are you sure the clicking is coming from the center diff? A lot of the strain is on the front diff. You can test this by lifting the rear of the car and moving the car back and forth. If you hear some clicking when you change directions, chances are that the diff input pinion is worn down/stripped and needs to be replaced (that was my experience anyways, YMMV). I suspect you'll need to replace the front and/or rear diff input pinions and then you'll want to spend a lot of time shimming the front and rear diffs properly. You really want to get them as tight as you possibly can. It took me a good while until I had the front diff tight enough so as to remove all clicking.

One other thing you should look at is the servo saver. As it comes from the factory, it's really loose and you'll find that the front wheels barely turn when the vehicle is standing still. They'll turn as long as the car is moving forward, but there's a cheap and easy fix. First you'll want to take the servo saver apart. If you've never taken an Arrma servo saver apart, it can be a bit of a chore and if you just try to crank it open, you'll probably tear the threads off one of the halves. This is the technique I use to take them apart.

I then cut 5 shims from a card blank (bank card thickness) by drilling a couple of 12mm holes with a stepped drill (spiral drill are impossible in thin plastic) and then cutting around the hole with a pair of scissors to create shims.
IMG_0695.JPG


I then stacked five of these shims on top or under the one metal shim that you'll find at the bottom of the servo saver.
1673652592998.png


Hope this helps :)
 

chazzz

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  1. Kraton EXB
Welcome aboard! Nice ride :)

I just bought a used EXB myself in December so, we were/are sitting in the same boat. For rust removal, you can use electrolysis to plate the metal, but that's a bit more involved. Just grab a wire brush and after you've given them a scrubbing, coat them with a little WD40.

Are you sure the clicking is coming from the center diff? A lot of the strain is on the front diff. You can test this by lifting the rear of the car and moving the car back and forth. If you hear some clicking when you change directions, chances are that the diff input pinion is worn down/stripped and needs to be replaced (that was my experience anyways, YMMV). I suspect you'll need to replace the front and/or rear diff input pinions and then you'll want to spend a lot of time shimming the front and rear diffs properly. You really want to get them as tight as you possibly can. It took me a good while until I had the front diff tight enough so as to remove all clicking.

One other thing you should look at is the servo saver. As it comes from the factory, it's really loose and you'll find that the front wheels barely turn when the vehicle is standing still. They'll turn as long as the car is moving forward, but there's a cheap and easy fix. First you'll want to take the servo saver apart. If you've never taken an Arrma servo saver apart, it can be a bit of a chore and if you just try to crank it open, you'll probably tear the threads off one of the halves. This is the technique I use to take them apart.

I then cut 5 shims from a card blank (bank card thickness) by drilling a couple of 12mm holes with a stepped drill (spiral drill are impossible in thin plastic) and then cutting around the hole with a pair of scissors to create shims.
View attachment 269639

I then stacked five of these shims on top or under the one metal shim that you'll find at the bottom of the servo saver.
View attachment 269640

Hope this helps :)

Turns out the clicking was just the magnets of the brushless motor. Rookie mistake.

I'll take a look at the servo saver. It moves a fair amount, but I've seen better movement on cheaper servos.

Thanks again,
 

Diem Turner

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Turns out the clicking was just the magnets of the brushless motor. Rookie mistake.

I'll take a look at the servo saver. It moves a fair amount, but I've seen better movement on cheaper servos.

Thanks again,
The magnets? Oh, you mean it was cogging?

Anytime (y)
 

chazzz

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Finally got started cleaning.

I'm going to soak the rusty screws in either a synthetic solvent or some vinegar and then treat them with WD-40.

Not sure how I can improve the state of the bash plate, have to look into treating and polishing steel.

So far the rear differential doesn't appear to need shimming. Also I'm not sure how to lubricate them once I am ready to reassemble, but all the teeth look great so far.

Edit - tempted to replace a lot of these screws with stainless steel but kits are very expensive ($30 - $70).
I won't be launching this Kraton but I will be going through puddles. Thoughts?

1.jpg


2.jpg


3.jpg


4.jpg


5.jpg
 
Last edited:

Diem Turner

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Finally got started cleaning. Going to soak the rusty screws in either a solvent or vinegar and then treat them with WD-40.

Not sure how can improve the state of the bash plate.

Also the rear differentials doesn't appear to need shimming. Not sure how to lubricate it once reassembling but all the tooth look great so far.

Edit - tempted to replace a lot of these screws with stainless steel but kits are very expensive ($30 - $70).
I won't be launching this kratom but I will be going through puddles. Thoughts?

View attachment 270918

View attachment 270920

View attachment 270921

View attachment 270922

View attachment 270923
Skip the SS screw kits. Stainless is a relatively soft metal and the hex heads strip out way faster than their hardened steel counterparts. Just get the regular steel screws. They may develop a little bit of surface rust but it's nothing to worry about. A little WD40 helps minimize it. I made the mistake of getting a stainless screw kit once. Never again.
 

chazzz

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Arrma RC's
  1. Kraton EXB
Welcome aboard! Nice ride :)

I just bought a used EXB myself in December so, we were/are sitting in the same boat. For rust removal, you can use electrolysis to plate the metal, but that's a bit more involved. Just grab a wire brush and after you've given them a scrubbing, coat them with a little WD40.

Are you sure the clicking is coming from the center diff? A lot of the strain is on the front diff. You can test this by lifting the rear of the car and moving the car back and forth. If you hear some clicking when you change directions, chances are that the diff input pinion is worn down/stripped and needs to be replaced (that was my experience anyways, YMMV). I suspect you'll need to replace the front and/or rear diff input pinions and then you'll want to spend a lot of time shimming the front and rear diffs properly. You really want to get them as tight as you possibly can. It took me a good while until I had the front diff tight enough so as to remove all clicking.

One other thing you should look at is the servo saver. As it comes from the factory, it's really loose and you'll find that the front wheels barely turn when the vehicle is standing still. They'll turn as long as the car is moving forward, but there's a cheap and easy fix. First you'll want to take the servo saver apart. If you've never taken an Arrma servo saver apart, it can be a bit of a chore and if you just try to crank it open, you'll probably tear the threads off one of the halves. This is the technique I use to take them apart.

I then cut 5 shims from a card blank (bank card thickness) by drilling a couple of 12mm holes with a stepped drill (spiral drill are impossible in thin plastic) and then cutting around the hole with a pair of scissors to create shims.
View attachment 269639

I then stacked five of these shims on top or under the one metal shim that you'll find at the bottom of the servo saver.
View attachment 269640

Hope this helps :)
Instead of shimming the servo saver I've been thinking about investing in this dialable one.

Might make the tuning process a whole lot more fun.

https://www.amainhobbies.com/hot-ra...YW7qwVWIZZz5p9EwzNQaAm5DEALw_wcB#tab-feedback
 
Last edited:

Diem Turner

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Instead of shimming the servo saver I've been thinking about investing in this dialable one.

Might make the tuning process a whole lot more fun.

https://www.amainhobbies.com/hot-ra...YW7qwVWIZZz5p9EwzNQaAm5DEALw_wcB#tab-feedback
Looks good. For me personally, while I'm not averse to spending lots of money on a car, if I can fix something like a servo saver for free, I can get downright thrifty. I'm also a jerry rigger at heart. But that thing should fit the bill nicely.
 

chazzz

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Another day of cleaning and exploratory disassembly.

I started off soaking any rusted screws in vinegar, scrubbing them with baking soda, and then spraying them with silicone lubricant. I definitely lost coating on the screws. I suspect they'll rust faster now... I'll just replace them as they rust and be diligent with the silicone lube.

Lesson learned : Just scrubbing with a brushed dipped in vinegar is enough to get the rust off.


after.jpg


Picked up some velcro hook like fasteners for the RX.

pads.jpg
rx 2.jpg


Inspecting the rear diff and the teeth look good but the grease is looking gross. Thinking about scrubbing everything clean and buying some diff liquid. Thoughts?

diff.jpg




I also have some significant grooves dug in the output cup (?). Think I can rotate them or this an immediate replace?

cup damage.jpg


cup damage (2).jpg



Here's the reassembled rear so far.

rear.jpg
 

chazzz

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All clean.

Replaced the worn out outdrive cups.

Cleaned out the diffs and I had a broken planetary gear. So I picked up a gear set.

Added some diff fluid.

45,000 front
500,000 center
20,000 rear

PXL_20230125_054254423.jpg



It's been really fun getting comfortable with the machinery. I am thinking about picking up :

- fast Eddy's bearings
- aluminum servo saver + bell crank
- set of mips bits
- spectrum SR6200A to add AVC & additional AUX channels for lights
- red lights


Wish I could get a Mojave or some other custom body.



--
 

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All clean.

Replaced the worn out outdrive cups.

Cleaned out the diffs and I had a broken planetary gear. So I picked up a gear set.

Added some diff fluid.

45,000 front
500,000 center
20,000 rear

View attachment 272924


It's been really fun getting comfortable with the machinery. I am thinking about picking up :

- fast Eddy's bearings
- aluminum servo saver + bell crank
- set of mips bits
- spectrum SR6200A to add AVC & additional AUX channels for lights
- red lights


Wish I could get a Mojave or some other custom body.



--
The upgraded bearings & mip drivers I wholeheartedly agree with. I run in the mud/snow/sloppy stuff A LOT now that it’s wintertime & those two things are a must in my opinion. Go thru a lot of wheel bearings. I've gotten multiple sets of the mip speed tips so I can have a 2mm & a 2.5mm in both a ratcheting driver & a cordless drill- just so I don't have to switch bits all the time. Makes disassembly so much easier/faster.
& I think those outdrive cups still have quite a bit of life left if you just flip flopped what side they were on
 
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