The Strongest Savage Diff Compilation.
 

Well, for starters I don't know what I'm doing wrong (or right). I have only ever run the stock Flux composite bulk and stock bulletproof diffs without any bearing or gear breakages. I've always run heavy silicon fluid in them (50K-100K) and haven't used any really heavy wheels or larger\longer can motors than stock, so that might have something to do with it.

Diff Case - I have a Vorza center diff and the case is a composite but felt very stiff. If these cases work it would be great as it also avoids loctite\silicon fluid in thread issues.
An alternative to a different case might be to just use a high quality ceramic bearing for the 10x16x5.

Spider Gears - again have never damaged one but would be nice to have a stronger option. Haven't heard of any other options.

Diff Case Screws - Hex heads are heaps better than stock. Have been using some that were in my Tony Screws kit.
Stock screw (M3x15mm) http://www3.towerhobbies.com/cgi-bin...529+&search=Go
HPI hex screw(M3x15mm) http://www3.towerhobbies.com/cgi-bin...?&I=LXMAB8&P=7
That said you can still damage the head and it would be great if somehow a larger screw could be used but that's unlikely. With the plastic case I have wondered if I could drill right through the case and put a lock nut on the one end. Probably not enough space in the bulkhead for that though.

What I would really like are harder outdrives. They are what wear on me the most where the dogbone pin rubs.

Well, I have run a few different savage diff setups.

Old 21/25 savages had 2 spider gears, you could upgrade them to 4 spiders with a hpi kit. Composite cups usually wore out where the cross shafts slipped in. Not good enough for regular mt wheels/tires and a feigao xl.

So I went to the hpi al diff cups. Curred the cross shaft issue as the shafts were in al tracks instead of plastic. However the ring and pinions started to break.So I tried shimming them, seemed to help but the rear ring and pinion went again. Blamed the flexible stock plastic bulks for that. Never had bearing issues but I have a feeling I would had the diffs held up better.

I do have a set of gh bulks with bulletproof gears in them. Have not run them yet, but they are said to be the best out there.

I do agree that heavy diff fluid should help the spider gears. Landing on one tire with the throttle wide open transmits alot of shock to the spiders.

Wonder if the hot bodies hardened spiders for the lsp would fit in the savvy diff cups? I have a set somewhere, will have to try. I know they do not fit lst diffs, but the cups are smaller on those.

imo the "evolution" of the savage diffs since the legendary savage 21 in 2001 (? or was it 2002) showed up went through several steps.

- the 2 spider diffs were upgraded to 4 spiders
- after that the little sliding blocs were introduced to prevent the cross shafts to work into the plastic cup. today these sliding blocs are usual in traxxas and hpi diffs in their monster trucks. this could be done with the plastic or the aluminium cups.
- the hpi cup was replaced with the kyosho part IF103 (uses a 8x16mm on a steel ring)
- the 43T gear was modified to accept 8x16mm bearings.
- later the outer-bearing modification was done to further strengthen the diffs and reduce the load on the inner bearings.
- several aluminium cups were offered in the tuning market since nearly the beginning
- the 43T bevel gear and 13T were hardened and called "heavy duty" etc etc
- with the savage flux the bulled proof diffs came with the 29T and 9T gears.
- of course various combos of the different mods were done.

bye
rhylsadar


here some old pics of some mods done to savage diffs.

a GH alum. diff cup
http://www.jaeser.org/~beat/images/2.../aludiff10.jpg

here a maximizer alum diff cup, the small sliding blocks, and prepared diffshafts to accept the outer bearings
http://www.jaeser.org/~beat/images/1...umn06_(33).jpg

prepared diffshafts
http://www.jaeser.org/~beat/images/1...mn06_(135).jpg

bevel gear with 8x16mm bearing
http://www.jaeser.org/~beat/images/1...mn06_(149).jpg

IF103 diff cup with 8x16mm bearing
http://www.jaeser.org/~beat/images/1...mn06_(153).jpg

diff with the inner and outer bearings
http://www.jaeser.org/~beat/images/1...umn06_(91).jpg

prepared bulk for the outer bearing, of course you can do this with alum. bulks
http://www.jaeser.org/~beat/images/1...umn06_(90).jpg

Informative post rhylsadar. Thanks for taking the time.

There is definitely a need for a decent diff cup. There was a guy starting to make titanium parts on Savage Central. I was trying to get him to make some but he hasn't posted in a while.

If only there was a composite\plastic cup with 8x16 steel bearing end cap that accepted the sliding blocks for the internals.

thanks for posting that thread!!!

i love the idea of all these extra bearings to help take the strains of these brushless systems!!!

_DV i knew that guy on savcentral was never going to produce... they rarely do after they realise how little profit there is in it for them...

Jason... do you really think the Hot Bodies or Kyosho plastic diff case with steel ring is better? does it accept the BP ring gear? and i also hears the spiuder and bevel gears are a little tougher too!!!
you got any part no. or links to them? thanks

hi

i have serveral different modded diffs in my savages.
one of the last things i have done is the 9T/29T bullet proof bevels combined with the kyosho IF103 plastic diff cup with the steel ring and the little sliding blocs. so there are now 8x16mm bearings on both sides.

i guess the outer bearing mod is only possible with the old non-x-version of bulks and diff housings.

the cen diff mod seems to be a very nice option too.

bye
rhylsadar

Yes i am running the BP Gears too... Definitely cant beat them for strength.

I am going to look into the kyosho diff cup... i really like the idea of the 8x16 bearing which continues to fail on me! Are you using the stock savage spider gears and sliding blocks with it?

I was going to buy these internal gears
http://cgi.ebay.co.uk/ws/eBayISAPI.d...T#ht_500wt_764

These gears are meant to be a little thicker and stronger than the stock savage internals... Do you think they would work?

Thanks for the help bud

edit..
is this the diff case that uses the 8x16 bearing and has the steel ring around it?
http://cgi.ebay.co.uk/KYOSHO-IF103-I...#ht_1073wt_750

You might want to check on those diff gears. I know HotBodies also has HBC8101-1 that are labeled as hardened steel, while the HBC8101 are just labeled as steel. They could be the same, but I would get the -1 version just to be safe.

http://www.hbeurope.com/piw.php?part...8101-1&lang=en

I am using these gears in my Jammin on-road diffs, but haven't had a chance to test them yet. They seem like they should be very solid though.

If you are thinking of using Kyosho 777 diff case, you can also use Jammin cases, which are the same as Hot Bodies too. Nova RC makes alloy cups, which I also have but haven't tested yet. Innovative RC in the UK also makes alloy Hot Bodies cups.

Yes I do, and Yes it does; time will tell if it really is a tougher combo. I don't have the Kyosho diff case, but from the pictures it appears to be identical to the Hot Bodies one I'm using now. I've read that the Hot Bodies spider gears are tougher too, but I'm using stock Flux gears for now until I use up my spares. It's all in my post that you linked to at the top of this thread. (link)

How did you get the sliding blocks in there? Pics??

hi

the IF103 cup is available e.g. at amain.
those sliding blocs are smaller than those in the hpi aluminium cup. you can see them in the second pic above. you need to modify the cross pins at the ends and produce some small blocs on your own.

i have only found a pic with the blue cup.

http://www.jaeser.org/~beat/images/2...4/aludiff8.jpg

bye
rhylsadar

These are the alloy cases being sold by IRC
http://www.innovative-rc.com/lightni...ver-p-209.html

They have the 8mm bearing capabilities... but do you think these would :

Firstly accept the BP Ring gear..

Secondly accept the HB Internal gears? http://www.hbeurope.com/piw.php?part...8101-1&lang=en

Thirdly accept the stock savage blocks? or would another block be required?


If yes is the answer then this is the alloy case we have all been waiting for?

Since the IRC cup is made for the Lightning Stadium and we now know the stock Lightning Stadium cup fits the Flux, it's a safe bet that it will fit.

Problem though is that aluminum isn't very strong when you thin it down, and the cup needs to be quite thin to accept the 8x10 bearing. The issue is further compounded by the diff shaft wallering out the cup sleeve from the inside until it becomes brittle enough to snap; this has been my experience with a turned down stock cup. With a steel sleeve this problem doesn't exist. Just my opinion.

What are these compatible with, internally and what bearing size? Has anybody used them?

http://www.fastlanemachine.net/prodd...LM44000&cat=22

alloy might not be that strong thinned down... but dont plenty of diffs use 8x16x5mm bearings.. .so why cant the savage? Also it will be going in my alloy diff cases so less flex in the diff area can only be better for it?

Im just worried that if i try the lightning diff cup, the internals i have wont fit...

Appears to be a Savage X cup which uses the 10x16 bearing.

The Lightning Stadium Diff Cup (HBC8019).

Its used in the D8/D8T and the Vorza. So it should be relavent for some time.

What about these, I ran them in my Losi truggy for...ever and they are great. Now what cup for the Savage and still being able to use the 8x16 bearing's? Kyosho's and who has the strongest spiders?

http://www.novarcproducts.com/diffcups.html

Or these... http://cgi.ebay.com/DIFF-CUP-Hot-Bod...item5adeab63f8

With these.. http://www.amainhobbies.com/product_...ntial-Gear-Set

They designed the HPI aluminum cup to accept the 10x16 for a reason. The HPI ring gear uses the 8x16 because it is steel, not aluminum. The only way to build a strong aluminum cup for the savage is to put a steel end cap on it, IMO. Can someone please prove me wrong . . . I would love to be wrong on this one. :yes:

What size bearing did the cup in your Losi use? If it was an 8x16, then my guess is the diff shaft was smaller in diameter to allow for a thicker wall on the cup. Just a wild guess here because I've never owned a Losi.

The Losi bearing is 8x14x4 flanged. I'm interested in this because I have decided to build a Savage from the ground up, so far I have a trans and RPM arms and a 1717 for the motor.

The other thing I was thinking was this.

http://www.fastlanemachine.net/prodd...LM40020&cat=22

and this.

http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

Or keep it simple and use these, I don't see these failing any quicker than 8x16's..

http://www.bocabearings.com/bearing-...OS7NB2-10x16x5

I have pretty much the exact diffs you guys are talking about, see my post here: http://www.rc-monster.com/forum/show...54&postcount=7

The only thing I'm not sure about is the ring gear, I'm using Sportwerks and Jammin ring gears.

FG101C, I think your suggested diff combo would be VERY tough! Too bad there isn't a diff cup like the CEN that is a drop in for the Savage.

simplechamp, What sized bearings does your combo use?

I am honestly thinking that if the main reason for this is to eliminate the 10x16 bearing that this is getting to be a bit much. I mean every rc is going to require some maintenance, and a good high quality ceramic should last.

I'm realizing how much and how long it's going to take me to finish this truck and it's making my brain hurt...:lol:

Plus I don't even know how to get thos FLM super hybrid bulks, Mike dosen't have them listed on the site and trying to email for info is likely not going to happen.:neutral:

Yea, if you want a direct drop in option, the Boca bearing with the stock Flux cup may hold up just fine, or you could try the Hot Bodies cup.

If you want to save some money and still have a tougher diff, you could just put the CENs in the stock Flux bulks. Of coarse, this would not be drop in.

8x16x5

Vorza Savage diff interchangeability?
 

Does anyone know if the Vorza ring and pinion will work in a savage flux? I guess the biggest question is the length of the pinion fitting through the diff housing. Do you think the helical gears would hold up?

No the helical gears of the vorza definitely wouldnt hold up...

MAYBE If they were in an alloy diff case with no flex... but i wouldnt try it...

:neutral:OK GUYS! I REALLY NEED TO GET MY DIFFS MADE UP!!!:neutral:

and need to just ask some final questions to see whether this will work...

Firstly... i think bocas are awesome.. .but im not replacing 2x $20 bearings every time i open up my diffs! So that is a no no for me...

I ideally want to get rid of the silly thin 10x16x5mm bearing...

So what will definitely be used???

The Spider Internals - Hot Bodies Hardened Steel Differential Gear Set [HBSC8101-1] As it seems these are the toughest on the market that work with the bulks we need to use...http://www.amainhobbies.com/product_...ntial-Gear-Set

RING GEAR - HPI Bullet Proof Ring gear

Axles - Stock Super Hardened Hpi Axles.


Regards to The Lightning Stadium Diff Cup (HBC8019). http://www.hotbodiesonline.com/products/en/hbc8019.html

You say that it would accept the:
BP Ring gear, HB Internals, and accepts the 8x16x5mm bearing. :yipi:

BUT as it is plastic, i just can not trust that it would be able to cope with the high power of a 9-10s Brushless system...:surprised:


It seems that the only cup that may work is the Lightning Stadium IRC Alloy Cup http://www.innovative-rc.com/lightni...ver-p-209.html

We know it fits in the flux
we know that the BP Ring gear is accepted and the screw holes all line up
we know the hardened spider gears will fit. (what slide in blocks?)
BUT WILL THE OUTPUT AXLES SHAFTS FIT from a flux???

SimpleChamp - Can you tell us exactly which IRC Alloy cases you are using??? You say they work with the spider gears mentioned... But do they utilise some form of slide in block like the savage??? And if so, which ones do you use? You dont by any chance have pictures of everything installed inside the diff cup to you?
Also are the axle shafts you have used, the same size as the SHD Flux ouput shafts???

THANKS A LOT
I think these are the only Q i need answering before i give it a go...

I am using the IRC Hot Bodies Lightning Stadium alloy cups. Nova RC also makes an alloy cup, any Kyosho 777/HotBodies/Jammin cup should work, they are the same size.

They DO NOT use a sliding block however, just the slots in the walls of the diff cup.

I am using the HotBodies hardened steel internals, 8101-1. I do not know if the SHD Savage outdrive cups will fit, they are listed as 9x11x34 but I don't know exactly what those dimensions are for. The outdrives used by the IRC cups (and most other 1/8 outdrives) are 6mm shaft.

I hope I have not been confusing everyone, but my diffs I built up are not in a Savage, they are in Jammin bulkheads. I just posted in the thread to let you guys know about the IRC diff cups and the hardened internals, and that they would work together.

Just out of curiousity... is it worth buying Titanium cross shafts???http://www.hpiracing.co.uk/product/ED070030,

are the stock ones made from steel???

I know Kyosho also makes titanium cross-shafts that will work with the Kyosho/HotBodies/Jammin cases and gears we've been talking about.

I'm not sure if you will see a noticeable difference in titanium over steel, and I think the titanium ones are pretty expensive. I am actually using the Ofna aluminum cross-shafts and they seem to hold up fine. Again, this is in a 1/8 buggy, so the Savage will be tougher on them, but I think steel or aluminum is fine (probably steel for the Savage?).

EDIT: Here are the Kyosho titanium shafts, at $15/pair you're looking at $45 for a set of 3 diffs. I'd just go for steel: http://www.amainhobbies.com/product_...el-Shaft-Set-2

thanks for the input champ... so im guessing i cannot use the stock steel cross shafts from the savage in the IRC Hot Bodies Lightning Stadium alloy cups?

Would i have to use the kyosho steel shafts? does this mean that they eliminate the need for the sliding blocks that are used in the stock savage diff cases???

THANKS
slowly getting closer, to understanding everything that is needed.

Why would you think the savage cross shafts wouldn't fit in the HB alloy cups when we already know they fit in the HB plastic cups?:neutral:

No; the savage sliding blocks cannot be used in the HB cups.

The Savage shafts should work fine, the cups are designed differently so no sliding blocks are needed. Here is the IRC Lightning Stadium cup with HotBodies hardened steel gears and regular steel shafts. You can see the slots that the cross-shafts fit into.

The Savage ring gear should be able to work OK with this diff setup. If the internals feel too loose you can add shims behind the gears. If the internals feel too tight try using 2 diff gaskets instead of 1 to space things out.

EDIT: I added another pic, this is what I call my "diff first-aid kit". Not a bad idea to put one of these together and throw it in your toolbox.

Champ, thanks for the info and pics...... clearing up a few things defintiely.
Loving your diff aid kit... i have a crazy number of diff bits, but its all in a greasy mess... i should really clean it all up.

ANYWAY LAST QUESTION...

It does make it easier that there are no sliding blocks.. but does that mean the cross shafts slide in perfectly into diff cup spaces without any side ways movement?
I just am so confused as to why they desinged the savage cup to use blocks? do you feel blocks to a better job of holding everything in place and prevents unwanted horizontal and vertical movement?

Im going to buy the alloy cups now. Im sure the BP diff screw holes will line up.

Not sure on the exact purpose of the sliding blocks, or the benefits of them. If I had to guess I'd say they are to stiffen up the plastic cup, or keep the cross-shafts from digging into the plastic cup? Most 1/8 diffs don't use sliding blocks, the Savage and few other vehicles that do are actually the minority. And with an alloy cup it's one solid piece of metal, so no worry about flexing anyway.

There is a tiny bit of play between the cross-shafts and slots they go into, but there has to be a little bit to be able to slide them in and out and let them rotate. The walls of the cup and 2 larger gears are mainly what keep the 4 small gears in place. The cross-shafts are to keep them on-axis so the mesh stays right. At least that's how I see it.

Awesome! Thanks for the quick response.

Im ordering the IRC Lightning cups now... Ordered the HB Hardened internals and some more diff gaskets just in case...
I was considering getting the alloy diff gaskets from the hellfire... JUST IN CASE i need to create a little more space, the alloy gaskets would help pull the ring gear out a little... or otherwise ill just shim the large side gears into the spiders if there is too much play... (i doubt it though as these HB Internals are meant to be thicker than the stock savage gears) Only can wait and see...

THANKS FOR YOUR HELP AGAIN CHAMP!!!!!! asset to RCM!

Love the diff kit simplechamp!