Kraton 3rd Run - New Diff Fluid - Pinion Broken - Noisy

[andrewh]

I've been out for my 3rd bash with my new Kraton v3. I'm using Backflip tyres and I've just changed the diff fluids to (1000s) 60 front, 500 center, 30 rear. After the change the running noise was much louder. I ran on 6s and the original pinion. The first jumps were fine, but when I went to do a speed run on grass, the pinion sheared within the first few hundred meters. I filled the diff cups with diff fluid to near the top. Any ideas what caused it to go this time? The car was much more powerful, with much more traction. My hunch is that the grip with the tyres on the grass and with more effective power it is creating too much torque. Do you think I'm right? Should I be changing the center diff fluid to something like 200, and should I use the original tyres when I'm on grass; or is it something completely different? Your advice will be much appreciated.

 

[TooTall]

Not too many things are going to make a pinion gear shear off, I would either a) the mesh was set too tight. b) you had a freak instance where some debris (rock, stick,etc) got caught in the gears. c) something happened inside a diff that caused it to lock up solid.

I seriously doubt the stiffer fluid would ever be the main source of the problem.
TT

 

[bicketybam]

Not too many things are going to make a pinion gear shear off, I would either a) the mesh was set too tight. b) you had a freak instance where some debris (rock, stick,etc) got caught in the gears. c) something happened inside a diff that caused it to lock up solid.

I seriously doubt the stiffer fluid would ever be the main source of the problem.
TT

Agree. I would guess gear mesh set wrong.

 

[olds97_lss]

Do you mean the pinion on the motor or inside the diff case?

Could just be you didn't get your motor tightened down and it walked on you a bit. Would also explain the extra noise. My buddy runs trencher 3.8's on his talion with 6S and 500K in the center diff without much issue, unless he doesn't get the mesh set right.

I ran the same tires, but with 100/500/100 in my diffs on my outcast and it's been doing fine. Granted, I've been running 4S. My 15T pinion has had at least 15 cycles through it and it's still fine. I get about 22-24 minutes on a set of packs. I was switching the pinion frequently trying to find a happy medium between heat and speed, but I ran it the most on the 15T pinion. Then I tried 14T and still had heat issues with the trenchers. Now I'm running lighter tires and I'm back to the 15T. I ran 4 sets of packs through it last weekend. Most of which on concrete (skate park) and grass. Lots of high grip and heavy throttle.

 

[Mr.Duke]

agree with the mesh theory

I beat the sh!t out of mine and run an identical filled the the top fluid setup (60/500/30/backflips) on a Tekno 15T (6s) with zero issues.
As soon as the weather breaks I'm throwing in a 17T

 

[andrewh]

Thanks for the replies. I've put a new pinion in and set the mesh - and it's much quieter. I've put it through some full speed runs and it all seems OK. Feeling more confident about the set up now.