Vorteks Keep destroying rear diff with a particular set of (heavier) tyres.

bukshypro

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I've got my data imo. Both times I destroyed my rear diff, was with the JetKo MT Extreme Tyre Tomahawk Belted on Arrma Granite Black Rims 14mm Hex (2) tyres. They are quite heavy compared to stock Vorteks, Louise RC MT MCross tyres, so the car can backflip and frontflip crazy, but this keeps breaking the rear diff. The weird thing is that I thought I actually lowered the load enough so that it survives:

  1. first time, I still had the 18T pinion on and I was going strong in the grass. 30-35k rpm full throttle, punch 5 and it just blew the rear diff.
  2. now, I had the 15T pinion, (20k rear oil, 30k front oil), 4punch, 15% timing (down from 22%) and it blew off in like 1 run and a bit on grass.
I don't really get it. the tyres are made for Granite/Vorteks/BR kind of cars and even my pinion is 15T now. Or is it actually that now there is even more torque on lower end? I am thinking to actually just straight get the full metal rear diff, but Im afraid I'll break that too. This is still only 3S Zeee lipos and not even lowest timing and not even full level 5 punch.

what am I doing wrong?
edit: the weight difference in tyres is 100gr / tyre, so 400gr more load on my diff. a metal diff might do it perhaps?

don't let me sad story confuse you, I'm super happy I gotta redo my rear diff again with all the re-oiling and such 😃
 
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Heavy and high bite tires will always do this. Larger Upgrade tires will do this, especially Heavier Belted tires.
A metal diff gear set is the only option available. Will that break? Probably less of a chance happening.
Drop the Punch and Timing completely down. Start low and work your way up.
Pulling hard with wheelies will get the best of your drivetrain always.
 

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I've got my data imo. Both times I destroyed my rear diff, was with the JetKo MT Extreme Tyre Tomahawk Belted on Arrma Granite Black Rims 14mm Hex (2) tyres. They are quite heavy compared to stock Vorteks, Louise RC MT MCross tyres, so the car can backflip and frontflip crazy, but this keeps breaking the rear diff. The weird thing is that I thought I actually lowered the load enough so that it survives:

  1. first time, I still had the 18T pinion on and I was going strong in the grass. 30-35k rpm full throttle, punch 5 and it just blew the rear diff.
  2. now, I had the 15T pinion, (20k rear oil, 30k front oil), 4punch, 15% timing (down from 22%) and it blew off in like 1 run and a bit on grass.
I don't really get it. the tyres are made for Granite/Vorteks/BR kind of cars and even my pinion is 15T now. Or is it actually that now there is even more torque on lower end? I am thinking to actually just straight get the full metal rear diff, but Im afraid I'll break that too. This is still only 3S Zeee lipos and not even lowest timing and not even full level 5 punch.

what am I doing wrong?

don't let me sad story confuse you, I'm super happy I gotta redo my rear diff again with all the re-oiling and such 😃
Don't know much about diffs but all i know is more weight more stress on those diffs. That plastic ain't made for that kind of weight.
 

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Heavy and high bite tires will always do this. Large Upgrade tires will do this, especially Heavier Belted tires.
A metal diff gear set is the only option available. Will that break? Probably less of a chance happening.
Drop the Punch and Timing completely down. Start low and work your way up.
I just weighted the tyres 😬 the stock an the Louise RC both weight 175gr, the JetKo weight 270gr each. that means 400gr more load on the car, so that all makes sense.
would you please be so kind and explain me the timing bit. I think with punch I'll be fine, I just turn it down since the car seemed to be absolutely fine to wheelie even with punch 3 on 75%. in fact, Im pretty sure the car was able to do standing backflips so there's tons of wiggle room to go down.
However what about timing? I heard/read the motor timing (set from ESC) on 22%(quite high) makes the car to go faster on high speed (bit more torque there) and lower timings would give more torque on lower levels. But then that's actually my problem right now, lower level torque destroys my rear diff.
so whats up with timing ?
also, if I have metal rear diff and that doesn't break, what's next to break? :S
 

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I go with a smaller set of tires.
 

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I go with a smaller set of tires.
I am not happy with how lazy the Vorteks is backflipping. by smaller tyres you only mean smaller by diameter or by weight or both ?
It made me so happy to see that with these, heavier tyres, the car wheelies and backflips waaaaaaay waaaaay easier.
 

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I just weighted the tyres 😬 the stock an the Louise RC both weight 175gr, the JetKo weight 270gr each. that means 400gr more load on the car, so that all makes sense.
would you please be so kind and explain me the timing bit. I think with punch I'll be fine, I just turn it down since the car seemed to be absolutely fine to wheelie even with punch 3 on 75%. in fact, Im pretty sure the car was able to do standing backflips so there's tons of wiggle room to go down.
However what about timing? I heard/read the motor timing (set from ESC) on 22%(quite high) makes the car to go faster on high speed (bit more torque there) and lower timings would give more torque on lower levels. But then that's actually my problem right now, lower level torque destroys my rear diff.
so whats up with timing ?
also, if I have metal rear diff and that doesn't break, what's next to break? :S
IMHO, Timing mostly increases the RPM's, and with that comes heat. Experiment with the lowest Timing first and evaluate for yourself. You will see what I mean. At some point the more timing increased, will not yield any great performance gain, just much more heat. I am always conservative with my Timing. Out the box , the default for Firma's are like 22.5 degrees of advanced timing, like my new FT. Just Too high to start with IMHO. What was Arrma thinking? I dropped it down to to 3.75. Yet to run my FT however. But this is where I will start. Punch I left at default for now. Very high timing can destroy a motor quickly. Been there. With a temp gun in hand, you will be able to see the motor temps drop with lower timing. Aside from Gearing of course, being another factor with motor temps. If I have a "Hot" Gear setup, I will also compensate by dropping the Timing in most cases.
If my motor setup is running hot, I always drop my Timing first and maybe even some Punch if need be.
A proper motor Fan solution is always a given regardless.
 
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It is not necessarily the weight of wheels/tyres that make them wheelie and flip better, more their ability to ballon.

For example, my X maxx on standard wheels and tyres will backflip much much easier than with Proline MX57s on, despite the Prolines weighing a fair but more.

Find a light tyre that balloons well and it will flip like you want, save diffs (and everything else heavier tyres will break) and drive nicer
 

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It is not necessarily the weight of wheels/tyres that make them wheelie and flip better, more their ability to ballon.

For example, my X maxx on standard wheels and tyres will backflip much much easier than with Proline MX57s on, despite the Prolines weighing a fair but more.

Find a light tyre that balloons well and it will flip like you want, save diffs (and everything else heavier tyres will break) and drive nicer
This is weird, because for me the exact opposite happend. Both the stock and Louise RC MT MCross tyres are lighter and balloon way easier but don't backflip, while the heavier JetKo don't balloon easily, but it pulls out of my hand when I pull the trigger. .🤷‍♂️
 

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This is weird, because for me the exact opposite happend. Both the stock and Louise RC MT MCross tyres are lighter and balloon way easier but don't backflip, while the heavier JetKo don't balloon easily, but it pulls out of my hand when I pull the trigger. .🤷‍♂️
Thats grip the more grip you got the easier it wheelies sometimes. Another way to wheelie is with ballooning as it lifts the tires easier from the ground. My car doesn't have much torque and the ballooning technic doesn't work on mine. I've a road that my cars gets easy grip and it wheelies like crazy. i would probably tip you just to get some smaller and ligher tires, if you can't do the balloon technic, find a place where you will be able to get grip easily. it you wheelie or backflip better there.
 

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I've got my data imo. Both times I destroyed my rear diff, was with the JetKo MT Extreme Tyre Tomahawk Belted on Arrma Granite Black Rims 14mm Hex (2) tyres. They are quite heavy compared to stock Vorteks, Louise RC MT MCross tyres, so the car can backflip and frontflip crazy, but this keeps breaking the rear diff. The weird thing is that I thought I actually lowered the load enough so that it survives:

  1. first time, I still had the 18T pinion on and I was going strong in the grass. 30-35k rpm full throttle, punch 5 and it just blew the rear diff.
  2. now, I had the 15T pinion, (20k rear oil, 30k front oil), 4punch, 15% timing (down from 22%) and it blew off in like 1 run and a bit on grass.
I don't really get it. the tyres are made for Granite/Vorteks/BR kind of cars and even my pinion is 15T now. Or is it actually that now there is even more torque on lower end? I am thinking to actually just straight get the full metal rear diff, but Im afraid I'll break that too. This is still only 3S Zeee lipos and not even lowest timing and not even full level 5 punch.

what am I doing wrong?
edit: the weight difference in tyres is 100gr / tyre, so 400gr more load on my diff. a metal diff might do it perhaps?

don't let me sad story confuse you, I'm super happy I gotta redo my rear diff again with all the re-oiling and such 😃
Is it the input or ring gear stripping out? Sounds like you drive hard so probably need an alloy diff yoke. They’re expensive, but you only need one for the back really. The front is fine most likely. You also have to check the gear mesh and service it about 8-10 packs after it’s first installed by removing the shim on the non ring gear side (save it you’ll need it again) and run it another 8 or so times. Then service it again and put the shim on the ring gear side. That’s the base rule I follow and adjust accordingly for each diffs ‘quirks’ and how hard I drive that particular car.
 

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Is it the input or ring gear stripping out? Sounds like you drive hard so probably need an alloy diff yoke. They’re expensive, but you only need one for the back really. The front is fine most likely. You also have to check the gear mesh and service it about 8-10 packs after it’s first installed by removing the shim on the non ring gear side (save it you’ll need it again) and run it another 8 or so times. Then service it again and put the shim on the ring gear side. That’s the base rule I follow and adjust accordingly for each diffs ‘quirks’ and how hard I drive that particular car.
Im not sure its hard driving. The car spent some short minutes in the wet grass, battery ended super quick and like 1-2 min into second battery I heard gears the slippin. I didnt take it apart yet, but its the rear diff 100%. In the grass we only bashed it, so no jumps or anything, just speeding and some wheelies.

The car had insane wheelie potential too. I see what I ll do. I ve seen a barely used Big Rock for £290, which I think I ll buy to use as parts/repair car and use the diffs from there. The metal diff costs £90. 🤦‍♂️
 

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Im not sure its hard driving. The car spent some short minutes in the wet grass, battery ended super quick and like 1-2 min into second battery I heard gears the slippin. I didnt take it apart yet, but its the rear diff 100%. In the grass we only bashed it, so no jumps or anything, just speeding and some wheelies.

The car had insane wheelie potential too. I see what I ll do. I ve seen a barely used Big Rock for £290, which I think I ll buy to use as parts/repair car and use the diffs from there. The metal diff costs £90. 🤦‍♂️
The ally diff yokes really help the stock diffs last as long as you service them and pay attention to the mesh like I had mentioned. I have stock differentials that are on their 50th pack or more with alloy yokes and proper servicing. Keeping the input/ring gear mesh tight is super important. Also, when you grease the ring gear just smear it on to the teeth, don’t fill it up. Ive tried several and like superlube grease the best. I’ve been doing a lot of experimenting lately, even using liquid gasket to seal that area. The below yoke is a bit cheaper then hot racing and works just as well.

BECF3CBB-7645-407A-A3AF-945A58883C61.png
 

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The ally diff yokes really help the stock diffs last as long as you service them and pay attention to the mesh like I had mentioned. I have stock differentials that are on their 50th pack or more with alloy yokes and proper servicing. Keeping the input/ring gear mesh tight is super important. Also, when you grease the ring gear just smear it on to the teeth, don’t fill it up. Ive tried several and like superlube grease the best. I’ve been doing a lot of experimenting lately, even using liquid gasket to seal that area. The below yoke is a bit cheaper then hot racing and works just as well.

View attachment 265389
Hmmm, can you tell me how would just metal yoke help if Id still leave plastic input gear and that big one?
 

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The stock, plastic yokes flex, which can affect the mesh between the gears. An alloy yoke, like the one Velodromed pictured, gets rid of most of that gear destroying flex and give the drivetrain some needed durability.
 

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Hmmm, can you tell me how would just metal yoke help if Id still leave plastic input gear and that big one?
That big one is the ring gear. A metal yoke stops the flexing that occurs during hard acceleration, braking and especially jumping, that can cause the diff gears to separate a tiny bit. Just need one metal yoke on the rear. The front experiences less stress than the rear so stock is fine. It really does help.

I don’t like most metal part upgrades. These 3s things need to be kept light and the wrong metal parts will cause the damage to travel to a more expensive part. My four, 3s cars are now mostly stock. On my two custom 4s cars I have metal differentials and yokes front and rear, 4s outcast cvds, m2c motor mount/brace, tower to tower chassis brace and metal spurs. But they can handle the additional weight.
 

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The stock, plastic yokes flex, which can affect the mesh between the gears. An alloy yoke, like the one Velodromed pictured, gets rid of most of that gear destroying flex and give the drivetrain some needed durability.

That big one is the ring gear. A metal yoke stops the flexing that occurs during hard acceleration, braking and especially jumping, that can cause the diff gears to separate a tiny bit. Just need one metal yoke on the rear. The front experiences less stress than the rear so stock is fine. It really does help.

I don’t like most metal part upgrades. These 3s things need to be kept light and the wrong metal parts will cause the damage to travel to a more expensive part. My four, 3s cars are now mostly stock. On my two custom 4s cars I have metal differentials and yokes front and rear, 4s outcast cvds, m2c motor mount/brace, tower to tower chassis brace and metal spurs. But they can handle the additional weight.

Awesome!! The knowledge on this forum is amazing!! Thanks everyone. I will get my parts big rock and thief off a diff and I'll be getting some metal yoke for the rear.

Btw I already noticed, 30k diff fluid in the front and the front tires didnt baloon even close to the back ones, hahA
 

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Awesome!! The knowledge on this forum is amazing!! Thanks everyone. I will get my parts big rock and thief off a diff and I'll be getting some metal yoke for the rear.

Btw I already noticed, 30k diff fluid in the front and the front tires didnt baloon even close to the back ones, hahA
What’s the rear at? If you go 30 up front should have 20 in back. I tend to run around 15 rear and 25 front. A bit higher on my 4s cars, around 20/30.
 

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What’s the rear at? If you go 30 up front should have 20 in back. I tend to run around 15 rear and 25 front. A bit higher on my 4s cars, around 20/30.
Haha, im pretty sure I took YOUR advice from some other threads, cuz yes I have 30k in front and 20k in the rear 😎
 

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Hey people, I thought I owe you a post portem. I did put in some effort (and m$$$$ney) and ordered all the metal parts possible for the car to keep up. I also speak to a friend and we ll see how could we produce some metal parts ourselves(whole another story).

For now I ordered full cnc rear diff, the separate metal parts for that too(to send off to my friend to make cad models of them), metal spur gear.

I will upgrade the car in full and put back the tires and just send it.

Happy to break the metal diff, the gears, pinion, motor or whatever. (Looking at the 4s cars tho, they use these exact same metal items by defaulg )


Edit. Jesus Christ, maybe it would just be better to send all these back and just straight buy a 4S car ? 🤦🏻‍♂️

Anyway, here:

Screenshot_20221228-155429.jpg


Screenshot_20221228-155410.jpg


Screenshot_20221228-155530.jpg


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