Having Maxx Diff problems need help...

[RespirologyRC]

:D The stock diffs are pretty good up until you start using .21 engines. My problem is trying to find a better alternative other than the $300.00 Unlimited engineering Supermaxx Diffs.. I have tried using the RRP hardened diff but have had even worse luck with those. What kind of diffs are you guys running with your maxxes? Currently I have a .21 comp picco engine, and have a .30 on standby (too cold to go out). So any advice will be helpful

[metalry101]

Do you run aluminum diff housings? Not the part that holds the spider gears, but the box that holds everything and sits between the bulkheads? The stock plastic ones are fine for stock power, but big power and lotza traction will put enough stress on the ring and pinion that they try to push apart. The stock plastic gearboxes don't resist that very well, and as such, even hardened steel gears will eat each other because they're not meshing properly under load. Even a cheap aluminum diff housing (I run Integy in my E-Maxx) will help eliminate that flex and help keep the diffs alive.

Also, the screws Traxxas spec'd for the plastic diff housing (the internal one that holds the spider gears) are ridiculously small. 1.5 mm if memory serves me correctly. Maximizer and Kippster both offer aluminum diff housings with 3mm screws that are infinitely stronger than the stock setup. I believe both of those can be had with either modidfied Traxxas ring and pinions or modified Robinson Racing ring and pinions. When I say modified I mean drilled and countersunk for the 3mm hardward instead of the stock 1.5mm. For the ultimate in bargain* bombproofness, I'd suggest both of the above modifications if you haven't done them already.



*Bargain compared to 1/8 diffs

[gotspeed_2000]

You've found out the basic problem with running .21 in a 8-10 pound monster with big wheels and tires. It puts a load on your drive train. I ran kipster diffs cups with modified robinson gears, it's a little cheaper than the UE 6 gear diff kits, but in the long run, you're much better off running the UE kits. The reason why IMO is the kipsters and others still rely on the same internal spider gears as all TMaxx's. These wear and over time, they were not designed to hold up to the torque and weight of the truck. That's why they work okay for a while, but still end up failing in the end. When I bought my kipster's, they were about 30 dollars for each cup, then another 30 for each modified robinson gear. That's already $120 just for the cups and the drive gear. Add the internal gears the drive cups and you're already out about 150. You can get brand new UE 6 gear kits for around 220. And these come with machined aluminum cases as well. Gear cases from even genenic brands sell for around 20-30 dollars for each case. So add up the parts cost, you're almost right there. So, I would think about it and you can decide in the end what is more expensive, buying the UE kits and having it last longer, or running the standard diffs or some other bandaid type diff kit. I really regret not getting the UE diffs to begin with. It would've saved me a ton of money. You can also pick up some used kits from their website. There are some people who part out the supermaxx's so the diffs are available there. Also, you might want to check ebay from time to time. Good luck.

[maxxamillion]

Also take a look at the Maximizer products Ultra Diff. No spider gears at all.
Dished washer(spring) setup. It works well if it setup correctly. And get the modified RRP & 3mm screw setup also. Ultra diff(RRP w/3mm screws inc.) = $90. And a I use a Dynamite(cheap, I know) aluminum housing, and your set for $150.
Puts the power down in the rear of my P2 Maxx.
I know the setup...

[metalry101]

^^^ I remember seeing that advertised a while back. It was intriguing, but I haven't really looked into it since. Is it pretty sweet? If I remember right it's adjustable, and can act like a limited slip almost? I'd definately consider tossing one in the front of my E-Maxx (I run a spool in the rear).

[maxxamillion]

Ya, its a posi, not a locker. I have mine setup tight so you can turn the wheels opposite directions, but with much friction. Less spin outs and easier on the drive train maybe, too(than spools). If its not setup properly, all the power will go to the other diff. In my case I had it too loose and all the power went up front(irritating). I tore it all down, added a dished washer per side and viola!, instant bad a$$ diff.
I swear by it. It helps my P2 Maxx hook up.
Roost city. :D
I'm running spools f & r in my HV Trail Maxx(thread in MT forum) for a mostly crawling setup.

[RespirologyRC]

I guess I'm going in the direction of the UE gears! Although some tracks are now say that you can't run 6 and 8 spyder gears. Maybe I can get away with it? But I have aan RRP with the 3mm screws but the ring and pinion keep destroying itself. I currently have a new Kippster just waiting to go on, but if it only going to get destroyed then I'll just return it ($40.00) and buy the UE and end my headaches now.

You guys are awsome!!! I didn't know that the diff cases themselves were seperating and destroying my ring and pinion. Who knew?