Kraton Bullet Proof diff question

ParkRacing

Well-Known Member
Messages
327
Reaction score
130
Location
Santa fe
Arrma RC's
I decided to tune all my diffs and wanted to do them well, while I was doing my research on this forum someone posted this video, "sorry I cannot remember which thread it was". however at 1:13 of the video the guy uses 2.2mm drill shaft to replace his stock cross-pin. I am just wondering, I have purchased all the shims, oil and new seals and gaskets, should I bother with this extra step?
*Has anyone ever broken these? is this a known part to break?

 

chalmene

Well-Known Member
Messages
181
Reaction score
103
Arrma RC's
I have never broken a pin. I've only broken a couple of the larger gears.
 

Kauaiguy

Well-Known Member
Messages
455
Reaction score
164
Location
Kauai
Arrma RC's
I have never broken a pin. I've only broken a couple of the larger gears.
I don't see the drill stock as a upgrade,the gear is made of much softer material ,so it will break first.Also the shaft the drill stock goes in to would need to be of hard metal.Something needs to give somewhere !
 

Vanning

Well-Known Member
Messages
1,147
Reaction score
549
Arrma RC's
I kept those pins as is for now....I have not busted anything in the diffs so far. I thought about doing it because I have cracked those types of pins in other vehicles... I shimmed the Kraton's diffs but kept the pin as is for now.

One thing I can mention to you on your build....if your front suspension is all the way down, you may feel the diff binding while turning one of the wheels. Mine was doing that and I decided to correct it. I just added a flat washer to the end of one of the A-arms. It moves the dog-bone away from the inner diff cup. This way it doesn't jam into the diff cup when the suspension is traveling all the way down and up. Jamming the diff cup like that may cause a gear to crack.

Some people noticed this and some didn't
 
Last edited:

heth

Well-Known Member
Messages
26
Reaction score
5
Location
Denmark
Arrma RC's
Hi Vanning

I did notice the diff binding on my vehicle. But if you want your wheels 100% vertical, I think you have to add a washer on both lower and upper arm, or am I wrong here?
 

Vanning

Well-Known Member
Messages
1,147
Reaction score
549
Arrma RC's
You are correct heth....I just corrected the problem on mine and at the same time got the camber where I wanted it. I had to mess around with a few washers and spacers both top and bottom. It didn't take much but I got it where it's fine for me. My front tires seem to have zero camber. It runs fine like that....It's no race vehicle so I don't think about it for too long. :) I do like that I don't feel that binding in the front diff. I rather have zero camber or slight negative....as long as it's acceptable...I'm good. I prefer a steel flat washer over the plastic C shaped shims. I kept loosing the C shaped plastic shims, they kept falling out.
 
Last edited:

Trickelitrick

Well-Known Member
Messages
244
Reaction score
181
Location
Sweden
Arrma RC's
I decided to tune all my diffs and wanted to do them well, while I was doing my research on this forum someone posted this video, "sorry I cannot remember which thread it was". however at 1:13 of the video the guy uses 2.2mm drill shaft to replace his stock cross-pin. I am just wondering, I have purchased all the shims, oil and new seals and gaskets, should I bother with this extra step?
*Has anyone ever broken these? is this a known part to break?

Actually i broke some of those pins....however....this happened always at the same time as the big gear in bottom of cup broke (twice and always same gear) so it could been cause it got shredded by the gears...now after shimmed the diff i never had any trouble tho so i wouldnt go for the drill shaft unless you reeeally wanna :)
 

ConanDan

Well-Known Member
Messages
29
Reaction score
13
Location
Denver
Arrma RC's
I broke one of my cross pins in the rear diff. I Replaced it with this repair and have had no issues sense...

I would not have taken the time for this repair otherwise :)
 

Jernberg06

Well-Known Member
Messages
11
Reaction score
11
Location
West Linn, OR
Arrma RC's
You are correct heth....I just corrected the problem on mine and at the same time got the camber where I wanted it. I had to mess around with a few washers and spacers both top and bottom. It didn't take much but I got it where it's fine for me. My front tires seem to have zero camber. It runs fine like that....It's no race vehicle so I don't think about it for too long. :) I do like that I don't feel that binding in the front diff. I rather have zero camber or slight negative....as long as it's acceptable...I'm good. I prefer a steel flat washer over the plastic C shaped shims. I kept loosing the C shaped plastic shims, they kept falling out.
What size washer do you use? Part number?
 

ParkRacing

Well-Known Member
Messages
327
Reaction score
130
Location
Santa fe
Arrma RC's
Well guess what guys...... I did the shimming and everything else in the video. Did super heavy diff oil ran it thru three packs and decided the oil was too thick for my taste, I am going with a standard truggy set up of 7 10 3...
Anyways what I wanted to say was when I pulled the front diff apart guess what.... a diff pin was broken in three pieces. So yeah a pin can easily break before a diff gear.

This must have happend at the very end of the run because there were no issues!
 

Attachments

Rich Duperbash

Well-Known Member
Excellence Award
Messages
896
Reaction score
1,988
Location
Roseville, CA
Arrma RC's
, ,
I wonder if you were 2 wheeling it for a while and didn't notice front wheels not spinning during last part of your run. Maybe drill bit upgrade has some merit. I'm surprised planetary gear didn't break first. I'd recheck clearances with your rebuild/shimming. Also heavy center fluid should remove extra load/free spin from front diff, may help from repeat failure if you're hard on the throttle like I bash.
 

ParkRacing

Well-Known Member
Messages
327
Reaction score
130
Location
Santa fe
Arrma RC's
I wonder if you were 2 wheeling it for a while and didn't notice front wheels not spinning during last part of your run. Maybe drill bit upgrade has some merit. I'm surprised planetary gear didn't break first. I'd recheck clearances with your rebuild/shimming. Also heavy center fluid should remove extra load/free spin from front diff, may help from repeat failure if you're hard on the throttle like I bash.
I don't know what happened? I don't bash that hard? Shimming may be too tight!
 

Trickelitrick

Well-Known Member
Messages
244
Reaction score
181
Location
Sweden
Arrma RC's
I don't know what happened? I don't bash that hard? Shimming may be too tight!
On my diffs i could put one shim behind both planetary gears on the centerdiff...on front and rear it got too tight so i losened the 4 screws just never so little until the diff felt good that way i could fit one shim on both planetary gears in front and rear. yes so i put 6 total :)
 

Rich Duperbash

Well-Known Member
Excellence Award
Messages
896
Reaction score
1,988
Location
Roseville, CA
Arrma RC's
, ,
I've only shimmed my center diff thus far, too busy with kids/life of late, I used 2 planetary total and 6 total satellite shims with 100k fluid and has been working great in Typhon where I had planetary gear breakage before. Plan to replace F/R diff fluids soon with new Outcast and shim if needed once gears break in and foul up fluid, in a pack or 2 more. 100k center worked well on Outcast maiden voyage, leaving to bash now.
 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Top