I've been looking at options to upgrade (for the helluvit) or replace (when they fail) my stock diffs (2.5). I won't/can't spend $230 EACH for the UE upgrades, so here's what I need to know.

1) If I want a "sealed diff" for silicone oil, is that controlled by the diff CASE, or the cup n' stuff inside?? Can you upgrade just the cup & gears (RR or UE) WITHOUT doing the cases, or are they critical for a sealed unit?

2) What's the skinny on the Maximizer diffs? They look nice & sophisticated, but do they work with the stock cases, or do you need AL ones? Are thy good for "cross training" (a little racing, a litte jumping, a little street work & a lot of general bashing), or are they really only suited to racing? Do you want to/have to grease or put silicone in these units?

3) I DO see how AL cases are good to have, regardless of if & how they affect "sealibility", as stiff cases don't flex & your gears last longer. So if I score some cases somewhere, what do I do next to create a sealed, durable diff for less than $100 a piece (not including th cost of the cases)?? Get RRs gears & keep rest of the innards stock? Get a maximizer, which is a complete unit? Does UE have any "gear-only" or "gear/cup" options that are somewhat affordable?

Thanks for any insight you can provide me!!

Dean

I don't have a Tmaxx but am fairly familar with it, so I can only be of limited help. If installing that engine into a stock tmaxx, here are the things that will HAVE TO be replaced.

- plastic CVD's to metal SCD's
- any plastic gear to a metal gear replacement
- replace all diffs. orginal diff housings can remain stock
- upgrade clutch to stiffer springs.
- go up 1 or 2 teeth on the clutchbell pinion gear.

I have the Maximizer diffs, They have an aluminum cup and 3mm screws. The screws are like twice as thick as the stock screws so they are much stronger so you won't shear the heads off. You do not need different cases to run these diffs, you can use the stock cases. Aluminum cases are more rigid and will keep the ring and pinion gears from losing mesh as easily, although I've never had a problem with the stock ones. As far as diff fluid, that goes in the diff cup to slow down the diff action. You can use it in the Maximizer diff cup, but it may leak out with time. The solution would be to put a thin layer of silicone around the rim of the cup when fastening it to the ring gear. You don't want to fill the case with diff fluid, because all that would do is slow down the power to the wheels. And you should always at least use some grease in the cup and ring/pinion.
The Maximizer diffs are the same basic design as the stock diffs, but they are much stronger. You can use them for anything you want to do.

Thanks, I'm getting there! What about the new "Ultra Diffs" from Maximizer? http://www.maximizerproducts.com/mpi_ultra_diff.html Is this "posi action" really just for racing, or are they good for all 'round performance? Would maybe ONE ultra and one reg. Max diff be the best setup (if so, which one goes where?)?

So the cup has the 'lil spiders spinning 'round inside. Do I ever need to replace THOSE, or are they not highly stressed & they'll be fine? Maybe the Maximizer comes with them, but they aren't shown in the picture on their site.

Do I want or need new bearings?

THIS $63 kit from UE seems to have a LOT more "stuff" than the Maximizer diff (but not a ring or pinion). Would it be a good choice (I'd add a Robinson ring/pinon for about $30 and I'd be set, RIGHT??):

http://www.unlimitedengineering.com/...Ihvt&mv_pc=981

While I'm at it, can anyone tell me why the entire 6-spider UE diff is $233 when the case is $60, the kit above is $63 & a ring, pinoin & bearings would be maybe $50??

Finally, what about Kippster stuff? Looks about the same as the Maximizer stuff, but frankly, I think the UE kit looks to be the best stuff AND the best deal, unless I'm missing something BIG re. what else I'd need to get with it!!

Thanks again!


Dean

The ultra diffs from Maximizer are cool. Being a limited slip, you'd probably only want them for the rear.

Wow, that UE diff looks awesome! It looks like it has everything you need. There IS a ring and pinion in the picture.
I don't know how I missed that, but I would have bought that set up instead of my Maximizers if I would've known.
The Kippsters are the same as the Maximizers, except there is a spyder pin that goes all the way through the cup, holding the spyders in place.

The Maximizers don't include the spyders, you have to use the ones you already have. If your bearings and spyders are in good shape, you don't need to replace them.

I bought the ultra diff .I built it according to the instructions,I could grab the front tires and roll the back(the ultra diff in the back)tires very easily (ultra diff slipping )so I reconfigured the springs so it was so tight I could barely get it back together it still slipped a ridiculous amount .so bad it obviously would not work so I removed it .in my opinion maximizer has not tested this product because it does not work.kippster's are the original maximizer is a copy .kippster makes hardened spider gears.dean it depends on what kind of power you plan to run.with my dynamite 26 pinion bearings only last about 10 tanks before they need replaceing my sirio goes through them in about 20 and this is a steady thing .I was looking at everything like you are now I went with maximizer because of the cost it hasent saved me any money I am disgusted to how they worked with the dynamite not as bad on the sirio truck.the ue stuff is running a bigger pinion bearing to disperse the load better .it hasent saved any money because I still need to get good diffs for my dynamite truck I have ue stuff ordered

Are you sure 'bout the ring & pinion? I thought the ring gear was big...bigger than the idameter of the cup itself, like the one in this Maximizer photo: http://www.maximizerproducts.com/Diffs.html

Maybe I'm calling things by the wrong name, I thought the "BIG" gear was the ring gear. I thought the UE photo showed 6 "spiders", 4 small ones & 2 bigger ones, and the pinion looks smaller than the one in the Maximizer photo, too!

In case you haven't figured it out, I've never taken apart a diff, so I don't know what's what!! So if I get these UE kits, I won't need ANY other diff parts right off the bat, or will I want one of the big RR/Traxxas gears like you see in the Maximizer photo?

Dean

In the picture you linked, the ring gear is in the upper left next to the cup. The pinion is in the bottom right. The larger spyder gears must somehow attach to the cups in the middle right of the picture.

I see!! The gear is face down & bolted onto the cup "cap"!!

That's what threw me, it wasn't "loose"

I see!! The gear is face down & bolted onto the cup "cap"!!

That's what threw me, it wasn't "loose"

I have no idea why there is such a difference in price between part # 13540 and #13542. Maybe the $63 price tag is a typo. The only difference between the two that I can see is the diff case ($60) and 4 extra 3mm screws. Hmmm.... maybe $275 is for 2 full diffs?

It has to be for 2 full diffs. If you buy 2 #13542's for $63 each, and 2 cases for $60 each, that would be $246 total.
Part #13540 is actualy $233, scroll all the way down, it's "on sale".

So if you buy it all seperatly, for a complete truck, it'll cost $246.
So it makes sence that part #13540 is $233 for a complete truck (2 diffs).