In your opinion. Strongest Centre Diff Available
 

As the title says...

I want a Centre diff which will be able to mount inbetween the RCM Universal diff mount.

The slipperential is a nice CD but im exploring what else is out there...

In your experience, what can handle up to 9s?

The Diff has to be able to manage the weight of a 14-15lbs savage

For internals, probably Hot Bodies hardened steel gears. Then maybe an alloy case, and most hardened steel spurs should work fine. Just stay away from the cheaper alloy or pot metal gears used in some diffs. Using thicker fluids will help to ensure the diffs don't unload too much in the front or side to side, causing extra wear on the gears.

Really though, Slipperential is a great option, you get the alloy case and hardened steel spur, but also the slipper protects the gears and will make them last longer.

I use a Xray diff on my MGT, very strong:whip:, but the problem is that you have 48T maxi spur gear:neutral:
My MGT weight approx 11 lbs

Hands down ofna spyder diff, aluminum case, 6 bolts holding it together. I have one if your interested

I have one of those too. Has a 52T spur as well, tho you can get smaller ones on ebay. I have a 48T for it as well.

+ 1 on the Ofna spider...:yes:

Alien

I know the benefits of running a slipper... but it seems that it is not entirely necessary. If this is the case, should i go for an ofna spider instead of a slipper? Would it be better for my application?

Thanks for the input so far!

BB16 how much would you sell it for? have you got a link for one? im not sure if i found the correct one

Can someone answer that question please ^^^^

Also what weight do people recommend running in the CD?
I really do not want to unload too much power to the front and cause my wheels to turn into pancakes...

What damage can occur and what usually lets go first if you have a bad accident and dont have a slipper on your diff? Is it the spur on the centre diff? Can you motor get damaged if there is no slipper???

someone can give the dimensions of this CD
ext BB to ext BB
and dimensions of the ball bearing please :yes:

I can adapt this one on my MGT for having a larger spur gear

End to end of drive cups - 65.5mm
Bearings (2) - 8x16x5mm
Diameter of aluminum cup - 30.56mm

I have one of each (52 and 48T).

I'm interested in this as well for a LST build. I have read somewhere arround 100k fluid is a good start, but I have no personal experiance.

-JB

Usually front and rear diffs go first actually

I Have had many cars with a center diffs, never hurt a spur, or a motor for that matter. The stuff we run is built to take the abuse.:party:

hmmm i would hate my front or rear diffs to blow as they are bloody expensive!
i may have to consider the slipperential then. Im sure the drivetrain will take a lot of abuse when running a 14-15lbs truck so a little give needs to be in there somewhere. Slipper would most def help.

100k fluid sounds very thick, so should be a good idea i guess to prevent unloading power to the front wheels.

Im going to put 50k fluid in my front rear diffs next as the 30k im running now seems to unload too much and too quickly to the opposite tire causing my tires to blow.

You should be fine without it, i ran my huge savage xl without a slipper and it worked fine. Ill have that spider diff if you want it

I'm running 50k in mine... it unloads with initial torque applied, but settles down and transfers power to the rears pretty quickly... If you're concerned about the front and rear diffs
cracking under pressure, just make sure they are all shimmed up right and they'll be fine...

Alien

hmmmm thanks for the input alien!
My diffs are all nicely shimmed and they are the Bullet proof diffs so they should be able to take the force, and of course they are shimmed....

My only concern now is how well the ofna diff fits in the Universal RCM Motor/diff mount...
It is larger than the slipperential which means it could fit with little or no shimming correct?

And when you shim a diff, cant you only shim it so much?

Yep... shims are employed to reduce the effect of 'play' when the parts are bolted together, thus allowing gears/cogs to mesh well under pressure... there is also the flip side to that... over shimming, will create drag
through out the drivetrain (in this case)... it will then lead to lowered performance and even over stressed electrics...

Regard the universal RCM mount facilitating a 52 spur, have a look at the below post by paralyzed:

'Making a 52t spur fit'


Alien

angry alien once again thanks...Bonus! that very little shimming is needed to get the ofna diff to sit just right.

I dont want to weaken the mount in anyway so def wont be doing that mod with the dremel.

I guess a 46t spur is the only way to avoid any clearance issues correct???? does this mean the 46t spur is one of the largest spurs i can run before having clearance issues???

Thanks

I have the 46:yes::whistle:

Prolly a 48T too w/ minor dremmelling. If you want I can take pix of the two diffs with my RCM mount. I have a Ofna spider CD, slipperential, and a CD form a Jammin X2. The slipdiff is pretty short. Mike really packed it in there.

http://i878.photobucket.com/albums/a.../gearingcd.jpg

And the reason i was wanting to do this CD Mount was because i wanted to get rid of the tranny for 9s use :) which should result in...

http://i878.photobucket.com/albums/a...earingon9s.jpg

This will be for my road setup :surprised:

finnster... i would really appreciate those pics :) of the ofna and the slipperential installed in the rcm mount! Thank yoU!!! how much shimming did you need to do for the ofna diff to finn?


BB16 so your ofna diff comes with the 46t spur already right... where can i buy rebuild kits for the ofna? and can i get replacement spurs in the RCM Store? if not... where?

11 tooth pinion I think you ment, along with the spur. Those numbers look good, though ~70mph may be difficult in such a large vehicle, even with 9s lipo for grunt- aerodynamic issues will be killer.

i dont know... i dont really care what top speed i get to tell you the truth... I just want it to be fast :)
But there is a savage on 6s hittin 79mph!

Link?

http://www.youtube.com/watch?v=Q8pyd...layer_embedded

His setup is 25t pinion/43t spur 39t idler (locked in second) and the stock flux torq 2200kv motor. He ran very hot just after a few runs but he was only going for high speed...

he has no burned that MMM because he was trying to run the same setup on sand = BOOM.

But he was just trying to push it as hard as he could. He is now geared more conservatively and is just bashing.

But it shows it is possible!

Hmm, pretty impressive, especially for such a large truck. I'd prefer to see a GPS & radar gun reading though- neither is 100% accurate so its a good way to get an average speed.

I actually have 2 diffs, 50 bucks takes both, one is in pieces though- all there.

are they 2 ofna diffs???

so nice !! :great::great:

but I need the length from exterior of the front ball bearing to the exterior of the rear ball bearing :smile:
and does exist spur gear of 49, 50, 51 T ??or only 48 and 52T ?? :eyes:

thanks :yipi:

Ofna Spider Center-Diff Hands Down!!! The fact that it has 6 spider gears (all others have 4, Traxxas has 2) makes it one of, if not the strongest diffs made!

One thing to remember, though, is if you decide to use the Ofna Spider Diff, you will need to use a lighter diff oil than you usually would in a regular diff, because having those two extra spider gears makes the diff oil act like a heavier diff oil....so if you normally use 7k in your CD, drop down to 5k...if you normally use 5k, drop down to 3k, you get my drift.

The Ofna Spider diff is the same size as any other standard diff from bearing to bearing, so it will fit in any mount that is made to fit standard center-diffs. The only problem you might have is if you are using the mounts for one of the smaller diffs like the Mugen or Hot-Bodies diffs.

yes that's it
My friend made the support based on the dimensions of the Xray CD, and it's a precise dimensions, no shim need :yes:
So I want to know the standard dimensions for adapt this mount to the largest choice of CD possible :smile:

If he made the mount to fit XRAY center-diffs, the Ofna Spider center-diff will fit just fine.

ok so if i was originally going to run something thickk like 100k to stop unloading power to the front wheels, i would then use 70-80k correct?

Im getting quite excited by the sounds of this ofna diff.
Do the ofna 6 spider diffs come in front and rear diffs too? it may be something i look into fitting into the savage later on

Yes:yes:

Yep... see the link and photos posted by George16 below:

'Ofna ravager 6 spider diff'


Ofna Hyper 7/UE 8 spider diff:
http://i256.photobucket.com/albums/h...Picture093.jpg



http://i256.photobucket.com/albums/h...Picture094.jpg


Other examples:
OFNA Front/Rear Spider Differential | Spider Differential, Front or Rear

Alien

nice1 for the pictures, i dont know how i havent seen these yet.....
The interior off the diff look ridiculously robust! Should easily be able to handle 9s!

I am not sure if i am going with the RCM Motor/diff mount now as i am still do not trust a motor just being bolted to the mount via a couple of screws... so i have rethought my idea thanks to _DV on the forum...

So with that in mind... i have found another Aluminium diff mount... Do you think, with the correct bearings... that this would work with the ofna diff right?
I can get this on sale for $10!!!
http://www.hpiracing.co.uk/product/ED010121,

http://www.rc-edit.com/graphics/part.../010121_01.jpg

I would assume so, so long as there is sufficient space for clearance underneath the spur ( between spur and chassis I mean ), otherwise a slot in the bottom of the chassis/ diff mount woudl be okay. Truth be told though I've NEVER seen a broken plastic center diff unit/ mounts, never. That would mean you could buy a whole unit complete with actual diff and just drop it onto the mounting plate, drill 4 holes and bolt it in place...

obviously performance comes first in my book, but if i can include aesthetics as well then its a bonus... If i REALLY have to go with a plastic diff mount then i will, but if this aluminium mount works then bonus! I would feel better using aluminium as i have a tendency to strip plastic screw holes

The only think annoying me at the moment, is that with a 46t spur, i am going to have to run a 10 or 11t pinion in order to not over gear so much.