New Flux diffs in a few weeks !
 

Right from Mark at HPI. Quote:
"We have a completely new and built up differential set coming out in the next 2 or 3 weeks. Tentatively called the Bullet-Proof Differential Set. This should solve all the differential breakage problems once and for all."

We shall see, I hope!

Damn .. that's to late I think I just broke my front diff :(

I saw they are releasing a new machined idler gear as well. Fewer teeth for a low tranny ratio (BrianG will have to update calc.)

Is this purely for speed, or have people been blowing up the tranny? I know they are cast parts, and have seen a few reports of breakage, but IDK if this is a good upgrade or not. I am nearly done collecting all the parts for my Sav XL conversion, but still need the idler and I'm not sure if I should wait for this part or just buy the cast cheapie idler.

Kudos to HPI to keep moving the Sav to an even more solid truck.

Hopefully they are going the right direction with it. I broke both the front and rear pinion gears in my diffs and have since gone to the nitro pinion's with an added shim. I am kind of seeing how much abuse they will take so I have been doing standing backflips pretty much as much as possible haha. They have been holding up for a while now. I think the teeth on the stock diffs are TOO hard and just shear right off.

hi

the "diff" problem exists since the savage turned up 2002 and was converted to brushless (or high power nitro engines). there are endless modifications of the savage diffs including the sliding blocks that were invented by advanced users long before hpi or traxxas put them into their factory diffs.
the usual reaction to diff damages was always to strenghten the diffs more and more. today e.g. cen diff mod or whatever mods are made to make the diffs stronger.

imo it is time to look at the problem from another perspective. more flexibility in the tranny especially the shafts would help. i am pretty sure good quality plastic shafts would help a lot to preserve damages on the diffs. in the case of a breakage replacing an outer shaft is much easier done and less time and money consuming than replacing the diffs. the tranny of the savage is just too "rigid" imho.

some nice high quality plastic shafts for the savage would be a very nice tuning part i would not hesitate to buy!

just my 2 cents

bye
rhylsadar

Not a bad theory rhylsader. But....In my experieince with the Revo (I know, a different beast), both are suceptible to failure. At least with the Savage line, shafts are at least not a known breaking point.
I have yet to blow a diff on my Flux - 7 months of running it now. I've broke a few other parts (bumper mounts front and rear). Which brings up one beef with HPI - why in Gods name do they need to sell complete tree's of parts???? I gotta buy the entire bumper assy just to get the one piece I broke. Maybe in the long run it will be cheaper for me, but for right now, it seems like that will drive up my cost.

yeah i also have quite extensive experience with maxxs and revos. and sure those shafts break from time to time. however i am quite surprised how good the standard diffs of an e revo e.g. hold up even under 6s abuse. the small trx diffs are imo on an absolute level weaker than the savage flux diffs. but they hold up pretty fine. of course the maxx/revo is weighing less than a savy nevertheless with some powerful BL setups the stress on the tranny is still there. i would think that the plastic shafts for the savage should be stronger than the trx shafts... maybe more like the new summit shafts or the like.

of course i am not sure if this would work out well as there are some many other factors. people who perform (senseless) standing backflips or jump and land with throttle/break still are able to break anything. last but not least an adequate slipper adjustment is important. but everything else equal i could easily imagine high quality plastic shafts would help to prevent diff damages and would produce a new intended breaking point in the case of too high peak impact.

bye
rhylsadar

did the same nitro pinion thing on my flux stuff and bingo, no more broken diffs. since I fixed the diff pinions, I've flew apart 3 trans gears.. diffs perfect. That's better.

So are you all saying the new trans gear will change the internal gearing? runs on the other gear in the trans or what??

The idler now has less teeth, dropping the FDR.

Interesting bit on the flux diff vs nitro pinions..

What part number are you guys putting in there? From what I could find, the Flux supposedly had the "good" parts in the diffs - but being new to HPI shopping, I could have overlooked it somewhere......

If they are only changing one gear in the tranny the case must also be different. If the idler has less teeth it will be smaller in diameter and it will need to be placed closer to the gear it meshes with in order to work correctly...

Where's that "DUH" emoticon.....guess I'll just use this one......:drunk:

(meaning Linc must be the only sober one here......)

110 runs in, zero diff issues here. Dunno what u guys are doing to them!

I wonder also, but then when I do - you know whats going to happen....blown diffs....

I also wonder about the people that count how many runs they have....!>!>!>

i havent had any problems with any of the savage diffs... both with 18 nimh cell and 4S lipo use, with stock savage 21, flux and upgraded alloy 4bevel gear diffs also... All diffs are shimmed well

probably around 146 runs on all of the combos combined.




-lol- sorry - couldn't help it hehehe

The flux has the two speed pinion on the input shaft right? I was assuming they were going to use the 2nd gear pinion (being larger) and just place the idler differently on the shaft.

Of course I was purely speculating. Seems easier than making a new case.


Edit: Where's my brew JT?.... lol

uhhhhhh - was that yours......?!?!?

Seriously, maybe I should start a new thread to ask this question:
I replaced my front and rear bumper mounts last night, and as I was doing so, it looked to me like it would be quite beneficial, and not very complicated to come up with a better means of retaining the hinge pins, and a better bumper mount (or possibly eliminate the bumper altogether).

Being new to HPI, are there any aftermarket products that already do this?

LOL, when I was reading that '146' I was like omg, should I also start counting my runs or what :D.

Anyways, seems my diffs are still fine, just broken my front bevel gear.

@ JTiessen, I, and many others, 'solved' it by putting a tyrip around it (not to thight because otherwise it will snap), haven't had a problem since. I know TCSCrawler had a brace made for this 'problem'. Altough after some bashing and testing he found out that the brace wasn't strong enough.

EDIT : @ Finnster (below) : Sorry, I meant the same as you. The zip ties just stop them from rotating.

What exactly is the problem?

The only prob I had was upper hingepins backing out as the upper bumper mount can rotate and not hold the pins in. I put zip ties around the two bumper mounts so they can't move apart from ea other, while the clips can still be pulled off and the bumper mounts pulled out to get to the hingepins and bulkhead screws to remove the diffs.

Has your bumper mount broke then, or ripped out the clips (as NC's soln seems to imply)?

I broke the screws off that attach the bumper to the bumper mount - did it on both front and rear. And in that same time frame I snapped the left rear drive cup in half. And judging by the way the plastic is chewed up around the lower hinge pin "stop" area there is a lot of movement in those parts.
I was just curious if there were any aftermarket systems for it. The first thing I always did with my Traxxas rigs was to rip off the bumpers - cant really do that with the Savage, it appears - unless there is an aftermarket hinge pin retention system that revises the function of the upper hinge pin retainer/bumper mount.

Obviously, I must have hit hard a couple times to do it. And that flex is probably very important to absorb the impact and not drive it further into the truck. Given the speed and weight of this truck (and my driving), I would probably be smart to keep the bumper system.

I wonder if they're going to do anything with the eSavage, probably not..

Damnit...

Rawbuns- do you have to have damnit in every post?

Sorry for the threadjack guys... :lol:

When HPI doesn't upgrade a thing on the eSavage, yes :yes:

So damnit! :party:

Hmmm - but they did. Unfortunatley, you can only buy it in a complete 650 dollar package, or in parts on ebay.

:lol: Besides the Flux, as in upgrades to the drivetrain in any way! :no:

kershaw designs has a eSavage tranny. it is based off of their electric conversion tranny for the nitro savages. it is better and lighter than the flux transmission.

My tranny is still very nice, but I'd rather have better diffs, other than the GCM Twin Diffs, which cost me an arm and a leg.

I'm running 6s with the punch control set to 100% and reduced the throttle curve. I've broken 5 rear diff pinions. I made sure they were shimmed properly each time I replaced it.

I now have the CEN diffs in there. I took it out for the first time a couple weeks ago and somehow managed to crack the rear bulkhead where the pinion comes out. I wasn't even driving it hard. The rear pinion completely tore through the bulkhead. Both gears were fine when I took it apart.

I got the bulkhead replaced and figured the damage was a fluke. Last Saturday, It was holding up great. I was driving fairly recklessly doing backflips off of jumps and had some bad landings that would've broke the stock pinion right away. At the end of the day, I did a standing backflip off a curb and heard something crack. After it landed, I heard the click from the rear diff. I'm pretty sure the pinion lost a tooth. I saw exactly what happened though. When I did the backflip, I saw the rear wheels hit the curb and that's when I heard the crack. I haven't torn it apart it to see the damage, but chances are the pinion broke a tooth.

Everytime I broke a stock one, It was from doing a backflip and landed hard. I always let off the throttle when i'm doing the backflips, but maybe i'm not letting off early enough.

The CEN gears seem to be significantly stronger, but not quite "bullet proof" yet. Then again, I am driving it harder than I probably should.

Hopefully HPI's new diff will be much better.

A good example of why warranties have small print!!!!

Glad you are having fun with it!

This thread is a bit old, but you asked me a question and I don't think anyone else answered it. I am using the NITRO savage pinion gear, with the stock flux bevel gear. I added a shim to the pinion, and it works awesome for me. Like I have said, I have done probably hundreds of backflips now (it entertains buddies lol) and since I changed a few things, no broken diffs.

Amen to that brother, In the last year I have EXPLODED a total of 44 spider gears in my FLM savage!! NO this is not a exaderation(11times x 4gears).
Everything is shimmed and built correctly. The truck weighs 18.5 pounds and has a NEU 1521 2d motor on six cells so torque is incredible. Have not tried the CEN diffs yet but the Flux mod does not help. Have been working with Jamie from FLM to try and fix the problem and no luck. :neutral:
So I hope to god they have this fixed.

Ok, so I was just on the site and this is not a diff set, but just the ring and pinion....no spider gears.

From the site...
This Machined Bulletproof Diff Bevel Gear Set is our toughest diff set-up ever for the Savage monster truck line. The ring gear and pinion gears are precision machined from high carbon steel and have stronger gear profiles for the ultimate in durability. The 29T gear is machined to use the included "oversized" ball bearing for extra durability and efficiency.

This diff gear set was developed for extremely high horsepower applications like the Savage Flux and Savage XL. It's so strong that it replaces the 86922 and 102246 Heavy Duty and Super Duty gear sets, both now discontinued. So if you're using big block nitro engines or high voltage brushless motors, get the new Machined Bulletproof gear set!

Each package upgrades one diff, we recommend getting a pair of them so you can upgrade the front and rear diffs. Fits all Savage trucks. Recommended for use with 102272 Composite Gear Box/Bulkhead Set

True, that news has been out for a while now ;).

You can order them for $25 a set.

So you have to buy these separate, they aren't updating the truck to make the drivetrain as tough as it should have been from the beginning?

I've read that from now on forward the Flux does come with the new Bulletproof diffs installed (offcourse when the old stock is sold). Think HPI got tired of handing out all the Bulletproof diffs that they decided to put then on in the factory.

That's good to hear. I have been toying with the idea of getting a Flux but the weaknesses in the transmission and differentials have kept me away from them. I tend to be rather rough on my RCs and I need something that can handle abuse well.

Well if you want to abuse a car then your choice for a Savage Flux is dead on. This truck really is tough as nails. The diffs are a weak point but with the new bulletproof diffs it makes for a real solid basher.

I doubted for like 3 months between the ERBE and the Savage Flux, but because we don't have a track nearby and I always bash I choose for the Savage Flux. No regrets so far ;) (almost 4 months).

Sweet, sounds like a good choice then. I love my Losi Muggy to death, with just a couple minor upgrades it's relentlessly durable and very fun to drive. The Savage won't drive nearly as well (being a Monster Truck rather than Truggy) but I'd like to have a secondary truck to bash when the Muggy is out of service.

I just ordered a pair of those. Figured that since I have to pull my rear diff off to replace the bulks/gearbox, I might as well replace the gears now.

Does anyone know if there is a difference at all between what HPI calls the "composite" gear boxes, and what comes stock on the flux? If they relaly are stronger, then I might try those before I pop for FLM's.

I am still not convinced on the new diffs, the problem with the stock flux diffs is that they were already TOO hard. If anyone looked closely at their broken diff you would probably notice the teeth were broken clean off.