Diff Longevity

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Cr3pitus

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Arrma RC's
  1. Granite
  2. Kraton 8S
  3. Kraton 6s
  4. Nero
  5. Talion
  6. Typhon 3s
Out of curiosity what is the consensus of how long a spiral cut 6sblx diff should last with an upgraded big boi motor? (4985)
Mainly I am wondering about the input gear and the spur on F/R diffs. I put in a 4985 last week and this weekend the input gears show some pretty legit wear, and the 43t spur on them are like a bajillimeter away from starting to skip gears. Been running the Talion hard for a couple months now so not sure if the wear is just from normal wear or was massively accelerated from the bigger motor.

Big motor aside, I virtually never land on throttle or brake, and the diffs are shimmed. No signs of wear internally, just the input gear and 43t are wearing down fast. Luckily theres a LHS that carrys them.
 
Probs too many unknown variables to give an accurate lifespan but yeah I'd be expecting diff life to be seriously reduced. If I got two thirds or even half the diff life with that amount of torque I think I'd probably be quite content.
 
I have the max6 setup in my Kraton and I brake everything twice as much as when I had the blx. Difs I mainly break the pins in side or the end of the cups where the pin goes thru. Also strip out sections on the ring gears. Also ruin the cups themselves and flatten the drive pins. The drive train was not meant to add two pounds of weight and more power...its fun though.
 
I go through a set of crown gears about every 20-25 packs per rig on average. Pinions will usually see 2 or 3 new crown gears before they need replacing. I'm pretty hard on mine but stay on top of all my maintenance. If I feel like I need to land on throttle to save a bad landing then I do.

plus I have stadium lights and bash at night drunk sometimes... so there's that too.
 
It never occurred to me to make a "bashing drunk" video until now.
IMG_2072.PNG


I may have to put that in the premium section though

I really haven't noticed an increase in the number of crown gears that get torn up running the bigger 4985 vs the BLX. Pay attention to your center driveshaft pins and cups though. I've seen an increase in wear on those running 500k and up center diff fluid
 
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I have the max6 setup in my Kraton and I brake everything twice as much as when I had the blx. Difs I mainly break the pins in side or the end of the cups where the pin goes thru. Also strip out sections on the ring gears. Also ruin the cups themselves and flatten the drive pins. The drive train was not meant to add two pounds of weight and more power...its fun though.
Haha yeah its definitely a lot, but yes, the fun is worth it. I actually starting cutting through the cups before I even switched setups. Pins too. But those are easy to get and cheap - If the $20 43t becomes a short term item thatll be sad. The 50t has like no wear, neither does the arrma 20t pinion I am using surprisingly - Just F/R seems more prone to the damage. Of course Jennys is out of complete diffs but that will be the way to go probably,, stocking up on those.
 
It never occurred to me to make a "bashing drunk" video until now.
View attachment 50877

I may have to put that in the premium section though

I really haven't noticed an increase in the number of crown gears that get torn up running the bigger 4985 vs the BLX. Pay attention to your center driveshaft pins and cups though. I've seen an increase in wear on those running 500k and up center diff fluid
I run a lot less viscous diff fluid than most here seem to do. I find I prefer 200k center vs the popular 500k on my Talion and for front and rear I'll go as as low as back to the stock 10k. The handing is just so good like that and all I seem to miss is 4wd when I get stuck on the crown of a berm or something. It does seem like now with this big motor I could go up in the center when I'm bashing around, might try 300.

Is it correct to assume that a thicker diff fluid puts more strain on the pin and cups whereas a less viscous diff fluid puts less strain on those and more to the internal diff gears instead from diffing out more?
 
I run a lot less viscous diff fluid than most here seem to do. I find I prefer 200k center vs the popular 500k on my Talion and for front and rear I'll go as as low as back to the stock 10k. The handing is just so good like that and all I seem to miss is 4wd when I get stuck on the crown of a berm or something. It does seem like now with this big motor I could go up in the center when I'm bashing around, might try 300.

Is it correct to assume that a thicker diff fluid puts more strain on the pin and cups whereas a less viscous diff fluid puts less strain on those and more to the internal diff gears instead from diffing out more?
It's all about personal preference.
Do you want a daily driver that's more dependable or do you want a high strung race car?
At some point you will be faced with the question of, do I want more performance and increased wear, which leads to higher cost to maintain... or go lightweight and a little less power to save parts.
Increasing center diff viscosity throws more power to the rear which has the majority of available traction. The result is quicker acceleration along with more heat and wear
 
I too have the Max6/4985 combo. Today I just got my package of driveshafts & hubs from Jenny's (really fast shipping, ordered on Wed, arrived Friday). My pins were wearing long before I made the swap. I also broke a hub pin & only spare pins I had were Associated 3mm pins. So I drilled out one of the rear hubs & axles. Boy that was a mistake, not just because of "wrong part, wrong car", I think it would actually do better with the 3mm cross pins, but it took forever to drill thru that hub, damn those are hard. Anyways, going for the rear cva swap, wish me luck! ?
 
I too have the Max6/4985 combo. Today I just got my package of driveshafts & hubs from Jenny's (really fast shipping, ordered on Wed, arrived Friday). My pins were wearing long before I made the swap. I also broke a hub pin & only spare pins I had were Associated 3mm pins. So I drilled out one of the rear hubs & axles. Boy that was a mistake, not just because of "wrong part, wrong car", I think it would actually do better with the 3mm cross pins, but it took forever to drill thru that hub, damn those are hard. Anyways, going for the rear cva swap, wish me luck! ?
Got you cover in here https://www.arrmaforum.com/threads/...-pins-on-arrma-6s-vehicles.14362/#post-178598
 
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