Kraton Newbie first run Kraton v5 - great, until it wasn't

[chocwheaton]

Hi all,

Got my Kraton v5 late yesterday afternoon. Amazing looking machine!

Read up on things to check before taking it on its first run:

1. Checked gear mesh (as best as I could without actually knowing what I'm doing )
2. Set steering dual rates- did make some minor adjustments
3. Checked all bolts were tight - one wheel nut was quite loose out of the box
4. Zip tied a few cables out of the way
5. Added a foam pad for the lipo tray

Then its maiden run this morning. Wow this thing is crazy fast. Did my first 6S lipo pack on 50% & 75% throttle setting in a big semi grassed field. So much fun. Really good to control out in the open. No issues. I almost felt like I knew how to drive it

Then the second 6S lipo. Did some 100% throttle as well. Not she wheelies, and some high speed runs on the field. Wow!

Then did a little driving in the car park...some more wheelies...and...what's that noise? Better stop.

I only ran it for a few seconds with the noise. Did an inspection and couldn't see any issues with my untrained eye taking a look over it.

I thought at first it was something in the front diff as it sounded like it was coming from there, so I headed home, took out the front diff (thanks google), inspected the gears and it all looks good. Re-assembled it thinking I got lucky and it'd be good now. I took it out again at lunch time, and as soon as I applied some power, it makes a grinding noise. Dammit! Why me!! Ha ha.

So I call my local hobby shop which is about 10 minutes drive away, and he has time to take a look this afternoon.

I head straight there, hoping it'll be an easy fix and I can go for another drive today.

The guy is super helpful, takes a look, and see's that the centre diff case is cracked and leaking oil. Hmmm...I missed that little issue.

One thing I like already about RC cars is how cheap parts are! So for about $30 in parts and the same in labour, they are going to sort it all for me. I considered doing it myself, but for $30 in labour for him to do it, I won't try this time..

I just have to wait 24 hours before another drive.

The guy at the shop said that driving on high traction bitumen surface is really hard on diffs, especially if you're doing wheelies. Arrrhhh...yeap that's what I was doing. My bad.

I guess I thought that if these cars can take big jumps and hits like on all those youtube vids, it'd have no trouble hooning around in a car park. I stand corrected. I was also probably very 'ham fisted' on the throttle and not driving smoothly either, due to in experience which would have contributed to over loading the diff.

The upside is I taught myself how to take out and install the front diff, and how to remove the motor, and adjust the mesh on the motor pinion and centre diff with a piece of paper. And now I know to take it more easy on bitumen.

I guess the fun learning has started

Cheers

 

[Pablo1980]

Strange ive never had issues driving my kraton in car parks, you may of been just unlucky from the factory maybe. On the good side tho at least you have now learnt a few things in maintaining the beast, carry on bashing and enjoy

 

[chocwheaton]

A quick question about my front diff assembly...there was a shim on the outside of the left hand side bearing (facing the rear of the car) and it did get a little bent during my attempts to get the diff back in. I left it off, but now think I probably need to put make sure it goes back in there, as it could be pushing the main gear over just the right amount to mesh well with the drive shaft gear.

This bearing shim is not included in the pictures in the manual for servicing the front diff, which is why I wasn't too concerned about leaving it off.

Do I need to put that back in before running the car when I get it back with the centre diff fixed?

Thanks

 

[Pablo1980]

A quick question about my front diff assembly...there was a shim on the outside of the left hand side bearing (facing the rear of the car) and it did get a little bent during my attempts to get the diff back in. I left it off, but now think I probably need to put make sure it goes back in there, as it could be pushing the main gear over just the right amount to mesh well with the drive shaft gear.

This bearing shim is not included in the pictures in the manual for servicing the front diff, which is why I wasn't too concerned about leaving it off.

Do I need to put that back in before running the car when I get it back with the centre diff fixed?

Thanks

Yes you will need it if it was allready there, like you said its there to make the mesh good, my one has it and without it there is too much movement which will cause a bad mesh and problems

 

[chocwheaton]

Yes you will need it if it was allready there, like you said its there to make the mesh good, my one has it and without it there is too much movement which will cause a bad mesh and problems

Thanks. It's a little bit bent. I'll check if it's the same size as the supplied diff shims. Hopefully I can use one of those.

 

[SrC]

Smash the shim flat as best you can and reuse it. If possible Be very careful. I smashed a few in the beginning. You need them.
I buy them in bulk to have on hand. You need spares. They are delicate and thin. I even got a few new smashed ones that were shipped in a soft envelope. AMZ replaced them for free.
That center diff has no crack. It is leaking because it was poorly assembled at the factory. Many diffs are like this. Also, better have diff oil on hand. All 3 diffs are probably very low on oil. Guarantee it. Best to wrench on your own rig, or you will never learn and then the hobby becomes expensive. These are meant for the hobbyist to work on. Part of the RC thing, being hobby grade versus toy grade.

Buy diff oil to have on hand. Replaced every 15 runs or so.
Most of us run 60k cst Front-500K cst center-30k cst Rear. Best overall performance. This is key to drivetrain longevity and reduces front wheel ballooning ( breaks the tires) and wheelying. Wheelies are a novelty in the beginning. Looks cool, but not really. Wears everything out. Want to control it best.

 

[LibertyMKiii]

Welcome to the forum.

+1 on a bad part. I do wheelies and run it hard on the street all the time with no issues.

My 2 biggest recommendations for a new owner of a 6s Arrma vehicle.

1. Get a set of MIP hex wrenches. They will have you hours of frustration over a stripped hex screw!!!
2. https://jennysrc.com/collections/arrma-kraton-6s-blx-ara8608v5

 

[ChicagoJT]

Welcome to the forum.

+1 on a bad part. I do wheelies and run it hard on the street all the time with no issues.

My 2 biggest recommendations for a new owner of a 6s Arrma vehicle.

1. Get a set of MIP hex wrenches. They will have you hours of frustration over a stripped hex screw!!!
2. https://jennysrc.com/collections/arrma-kraton-6s-blx-ara8608v5

This is the best advice. Ask questions here. Many people have helped me. I'm not the most mechanically inclined, but between this forum a great LHS and YouTube I've been able to keep my RC's running well...