Revo tranny center-diff opinions?
 

Anybody use the Traxxas center differential (#5414) in a Revo tranny, under brushless power, and how’s it working out? I like the traction gaining benefit of unloading power to the rear if the front wheels come off the ground; just like a traditional buggy. Downside is this piece is prone to significant forces and likely to munch.

Anybody use with success?

http://www2.gpmd.com/image/t/trac9414.jpg

Actually what you described for unloading is a little in reverse.

With the current MT setup of a tranny center you have no unloading of power front to back - front and back wheels are always getting the same power with a locked center driveline.

With a center diff - if the front wheels come off the ground then the motor power will push to the unloaded front wheels and you'll get less power to the rear wheels - the thicker the diff fluid you put in the center diff will reduce the unloading of power to the front wheels and give the rear wheels more power.

I've read in other threads that the Traxxas center diff is pretty weak, only has two gears in it so you have to use much thicker oil than you normally would, can't stand up to real BL power, and really isn't worth the money.

Personally I like the locked center in the MT - just makes it more fun for bashing around and wheelie action. :wink:

I have tried the Traxxas CD w/Kyosho 500k fluid in a converted BL Revo and not much of a difference from not using it

damn 500k is like just pouring a bunch of epoxy in there :lol:

yeah..its very thick ...the only think thicker is diff lock

mine with 120,000w is holding up just fine to the Nue 1515 2.5d

I tried the Traxxas CD in my converted 3.3 revo. Diff lock almost stopped the front wheels from constant spinning (faster then the rears) but at that point there was no real advantage to to using it anymore. I believe that aside from the minimal number of spider gears used that the long travel suspension on the revo helps work against the CD.

If your just trying to keep your front end on the ground I've found all of the following to be more effective and less annoying then the traxxas center diff.

1) extended rear A-arms (these make a huge difference)
2) move your batterie/s forward to better balance weight distribution. (this can help steering also)
3) properly adjust your slipper (it's amazing how very small adjustments can effect the slipper)
4) teach you throttle finger some self control.
5) if you like the way 2wd trucks brake in the dirt then get a quickturn front driveshaft. (many people swear by them but I could not get used to it)

So is the Platinum edition a waste of time with the Center diff option? I am think the E Revo, btu then again, the Plat has the center diff.

IMO if the Platinum has the same CD has the 3.3 than yes

does anyone know if the traxxas CD will fit into the erevo tranny?.....

my guess is no since it is a completely different design

anybody gunna make a center diff for the e-revo?

See this thread. Linc is.

http://www.rc-monster.com/forum/showthread.php?t=15001

The erevo uses a 33t lower gear, while the revo uses a 29t. Plus I could not find a nylon 33t gear that could be modded to work, that is what cowboy did to make his conversion for the revo, 29t nylon gears are more popular...

I am working on the diff, but have heard that traxxas may make one for the erevo/emaxx. I am sure it would be a 2 spider design like the revo one, which is not optimal IMO... So my idea may still be desired, especially for brushless which seems to require heavier fluid and more "limited slip" effect than nitro.

well, linc...it looks like traxxas beat you to it, however, I'll more than likely purchase from you.....hopefully you can keep the price comparable to the traxxas one......has any one thought of buying the new traxxas gear and putting there own cup onto it?

I seriously doubt I will be able to sell the whole deal for 40 bucks. Maybe the adapter, modded gear and the shafts... Even then it may require some shims depending on which diff cup is used. I would like to offer the whole deal as a kit that includes everything. Diff cups are about $6, internals $7-12, not sure what the modded output shafts will cost, and shims, plus modding the stock lower gear, and hardware...

Might be too pricey, probably close to 60-70 bucks... or more depending on what the machinist charges...

here is a question for you...since traxxas came out with there's and hopefully you can buy just the gear, like you can with the nitro revo, couldn't you just use the gear and put your own cup/internals...ect. on it and help reduce the machine time on the gear, and the cost as well...the question would be, is which cup is a direct replacement and that can hold the 4 spyders that we want...

here is a pic of the traxxas on w/ gear...
http://img.photobucket.com/albums/v4...centerdiff.jpg

here is another question, ae all diff cups bolt pattern the same......does anyone have any info on this....

linc, just to let you know....im not trying to deter your sales possibly ect.....just tossing ideas out there to try to help figure out the best & most cost effective way to make one strong enough for us...

I can tell you that the cup above is a stock emaxx or revo diff cup. I would think a 6 spyder type internal would work fine, it's the cup I would have issues with. What anout a maximizer cup? Don't maximizer's work with emaxx old style diff's? So the question here would then be, how can you get the proper internal's?

Linc, nova-rc makes aluminum cups for the ofna gears.

http://search.ebay.com/search/search...ial&category0=

You can install the 6 spider gears inside.

If traxxas will sell the gear seperately we may have a winner. I would just mod the adapter that I am having made to bolt to this gear. Hopefully they sell it seperately, as they do with the revo center diff:

http://www3.towerhobbies.com/cgi-bin...?&I=LXMHV6&P=7

No problem, the more ideas I here the better the finished product will be! I am glad you posted a pic of the erevo center diff, now I can see what it looks like. Where did you find the pic?

The maximizer cup uses std traxxas internals, so 2 spiders and 2 output gears. I will see if I can get my hands on a center diff kit, and try to use the gear on my adapter. I have a revo center diff, wrong number of teeth, 29 vs 33, but it should be the same size...

By 6 spider, you mean 4 spider gears and 2 output gears? A six spider diff is like the ofna spyder diff, and the ue diffs. A 4 spider gear diff is like a std 1/8 buggy/truggy diff.

Yup. 6 spider gear = 2 bevel/sun gear and 4 side gears.

Ofna ravager 6 spider diff:
http://i256.photobucket.com/albums/h...Picture006.jpg

http://i256.photobucket.com/albums/h...Picture014.jpg

Ofna Hyper 7/UE 6 spider diff:
http://i256.photobucket.com/albums/h...Picture017.jpg

http://i256.photobucket.com/albums/h...Picture018.jpg

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

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

What UE sells as 6 and 8 spider diffs are nothing but Ofna Hyper 7 6 and 8 spider diffs. UE just added the diff outputs, shims, and Ultralite cases in the kits they sell for $$$$.

Yeah, but is the cup the same diameter as the maximizer? Looking for something that can hold a 6 internal, yet bolt up to that gear.

I doubt that you will find that. Looks like traxxas uses the gear on the center diff as the cover.

When cowbody made the setup for the nitro revo he used a different gear, as he had it machined to mount to an adapter that acted as the diff cover.

My main issue with the traxxas design is that it uses the output shafts to hold the assembly up via the stock bearings. I plan to have the diff case and my adapter run on bearings, and the shafts will run inside the diff and the adapter, just like they do on an 1/8 scale diff. Should last longer and rotate true. Plus my design will have a 4 spider diff, not the 2 spider traxxas setup.

This whole diff issue is making me wish I kept my maxx just for the simple fact it had the slipperential. I hate constant wheelie's and bad power distribution. I still think FLM and Mike should take the FLM tranny case, reform the lower half to hold a 1/8 diff, and then incorporate the slipperential gears to also fit. Somewhat like a slipperential, but with the tranny so you can still use the motor mount.

If they would design a new case that was similar to the new emaxx/erevo case, make it so that it uses the same input shaft and idler, but has the lower area remade to accept a diff. It would have larger bearing areas to accomodate 8/x16 bearings, and would have custom made output shafts. They would have to either make a 33t gear, or mod the existing gear like I will. The only real difference would be the larger bearings. I am stuck using 8x12 bearings as the stock tranny case has 6x12mm bearings stock.

I plan to use ceramic bearings, best that I can find.

Exactly my idea. I sent the idea to Mike yesterday, no response as of yet. I hope he thinks about it.

We will see. I will continue my quest to get a decent diff in the stock tranny case...

Linc, i found the pic on the traxxas forum, yesterday.....but it would be nice to atleast to be able to have 4 spyders inside it......may have to do some browsing to find a simular cup to match up to the gear, that will hold the spyders we want....I'll let you know if i find anything

Well, after searching all afternoon, I was unable to find a suitable diff replacement to house the 4 spyders, I did however find on the NOVA rc site a aluminum diff cup, which may work, also....Im considering buying a set of hardened diff internals, like hot bodies ect, i may try the set I have sitting in a old ofna dominator diff.......Linc...do you have an rough pics or sketches on what you are trying to do..ie adapter ect.....I may just get the traxxas one...and drop a different set of internals in... any suggestions....I also looked at the bolt pattern of other diffs & the raxxas one, more than likely it only has 2 spyders, much like the nitro versoin...this is due to the bolt location.....

I should have some close to finished pics up in a day or two. I have figured out the bearings, shims and measured all of the various lengths. I need to have the machinist tun the adapter down, bore out the lower gear, and mill that gear to a certain thickness. I have to narrow it slightly, which should not cause any strength issues. I will drop off the parts tomorrow and should have them back friday.

cool, if your design works, and appears to be stronger than the traxxas one......I think i may get it...not sure...just figuring stuff out....your design does incoperate 4 spyders right......i think i read that?

I'm interested on this too.

George, thanks for the very clear pics....im sure that cleared up alot about the diffs.....kudos...man

No problem bro :party:.

Hey, I haven't seen you in the UE forums lately?

your right, I havn't been on there lately....the reason is I sold my UE/Gmaxx chassis & kept the tires,electronics ect......even though I worked hard to get my truck the way it was...It came to a point...when funds where needed....so I sold it....and now have replaced it with the Erevo.....it was a tough decision...but I had to do what was needed., I go on there everyonce in awhile....just to see whats up is all/....

Yup, almost everyone is leaving the Supermaxx scene. Chadknorr is selling all his stuff and so is JD. Sad thing to see indeed. I just "retired" my son's SM and it will just be a static display.

yup it is sad, the product is excellant, however the parts are far and in between, but when they don't have product supposrt...it makes it hard to keep them around....I'm sorry to hear about your son's trck being a show piece....I think UE missed the boat when it didn't release the razorback......and hate to say it, but the maxx plateform is a aging....