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Blown both Diffs in brushless lst?

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Old 10-06-2012, 09:54 AM
  #1
sparky 25
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Default Blown both Diffs in brushless lst?

Took my lst out for its maiden brushless run,

I'm impressed with the handling and glad I fitted the losi wheelie bar,

There started a loud crackling noise at the rear, which got worse until rear drive was lost just 10mins into the run,

Then the crackling noise switched to the front, until all drive was lost,

I'm running a 4074 2364kv motor on 4s 5200 with a 25t savage flux pinion,

With a 63t spurgear,

I had the Diffs meshed perfectly and was surprised the lst Diffs didn't last a full lipo charge

Are there any upgrade Diffs that fit the lst trucks?





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Old 10-06-2012, 11:43 AM
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Default RE: Blown both Diffs in brushless lst?


Quote:
ORIGINAL: sparky 25

Took my lst out for its maiden brushless run,

I'm impressed with the handling and glad I fitted the losi wheelie bar,

There started a loud crackling noise at the rear, which got worse until rear drive was lost just 10mins into the run,

Then the crackling noise switched to the front, until all drive was lost,

I'm running a 4074 2364kv motor on 4s 5200 with a 25t savage flux pinion,

With a 63t spurgear,

I had the Diffs meshed perfectly and was surprised the lst Diffs didn't last a full lipo charge

Are there any upgrade Diffs that fit the lst trucks?





Chances are the plastic diff cups exploded. I had it happen on my nitro lst2's. Get the HD diff cups for an 8T. They are much stronger and are what I used when my Mach 427 ate a diff.
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Old 10-06-2012, 01:35 PM
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Default RE: Blown both Diffs in brushless lst?

The ring and pinion gears are destroyed, the diff cup is perfect still
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Old 10-06-2012, 01:49 PM
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Default RE: Blown both Diffs in brushless lst?


Quote:
ORIGINAL: sparky 25

The ring and pinion gears are destroyed, the diff cup is perfect still
Wow... Never heard of that happening on an LST or LST2. Those diffs are tough as nails. Did the screws that hold the ring gear to the diff cup come out or snap? Mine snapped 2 screws off and the ring came loose. My ring and pinion gears didn't get destroyed though.
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Old 10-07-2012, 01:15 AM
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Default RE: Blown both Diffs in brushless lst?

Nope nothing loose, just both Diffs ate alive,

The bearings are all good also,

Are the lst xxl Diffs any tougher?
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Old 10-07-2012, 02:20 AM
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Default RE: Blown both Diffs in brushless lst?

Found the problem,

the plastic holder that the diff and pinion gears sit into have 5 or 6 fractures each this allowed the gears to mesh loosely under load and stripped the gears,

I'm going to look for complete lst2 or xxl Diffs with the alloy cases.

Know anyone who sells complete lst2 or xxl Diffs with outer cases?
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Old 10-07-2012, 10:00 AM
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Default RE: Blown both Diffs in brushless lst?


Quote:
ORIGINAL: sparky 25

Found the problem,

the plastic holder that the diff and pinion gears sit into have 5 or 6 fractures each this allowed the gears to mesh loosely under load and stripped the gears,

I'm going to look for complete lst2 or xxl Diffs with the alloy cases.

Know anyone who sells complete lst2 or xxl Diffs with outer cases?
I kinda figured it wasnt the diff itself. I thought all LST, AFT, Raminator, and LST2/XXL trucks had aluminum diff cases... Anyway, *bay is probably your best bet. There are a bunch of folks buying whole trucks and parting them out. The Diffs in the XXL or LST2 have alloy cases but I dont believe either one comes factory with the HD diff cups the 8T comes with. I would buy the 8T diff cups when you buy the complete diffs. If you properly shim your diffs, you will have diffs that will outlast most of the rest of the truck. The LST trucks really are pretty hard to beat up.. My LST2's just keep taking the abuse.
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Old 10-10-2012, 05:46 AM
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Default RE: Blown both Diffs in brushless lst?

sparky, I am in a process of upgradring my lst to brushless, about the battery, would you recommend the 4s or 6s? this will run on mamba 2200kv, I heard 6s is too brutal to run but just not too sure before I place an order w/hobbyking...thanks.
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Old 10-10-2012, 09:10 AM
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Default RE: Blown both Diffs in brushless lst?

I run my savage flux with mamba 2200kv on 4s,

Trust me its bags of power,

I'm running a 2364kv motor in my brushless lst and with 4s it would be undrivable without the wheelie bar,

The only thing you really should buy is metal diff holders as the stock lst plastic that the Diffs sit into will fracture first time out,

I had mine shimmed perfectly and got just a couple passes before I could hear the Diffs crackling,

The best batteries for the money are turnigy hardcase 30c 2s 5200 batteries,

I also have zippy hardcase 30-40c 2s 5200 batteries, but the turnigy definitely have more punch to them,

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Old 10-10-2012, 02:03 PM
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Default RE: Blown both Diffs in brushless lst?

thanks for the advice, so for the 2s, I would assume that you are running them in series of 2?
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Old 10-10-2012, 08:06 PM
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Default RE: Blown both Diffs in brushless lst?

Hello,

My Muggy came with plastic diff case and the LST2 XXL diffs comes with the 8T heavy duty diff cups. My LST and my aftershock also had metal diff case.
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Old 10-11-2012, 01:23 AM
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Default RE: Blown both Diffs in brushless lst?

Bugeyes ,

Yea running two 2s lipos to make 4s,
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