alright, i was at my hobby shop and i picked up some 50K diff lube, the reason was because the shop owner said that you will notice a better throttle response. Now before i picked it up i was running top gearing at 31/76 with the vxl setup. then i switched to 18/90 after i replaced the tranny gears. it ran better and i noticed better throttle response which was probably because of gearing. but now tonight i switched to 31/76 and it takes DAAAAYYYSSSSS to get to top speed and my exceleration is veeeeeeery slow!! is this normal....is 50 000 weight too much?

Something must be bound up. I packed mine with grease and I can still light up the tires.

the 50k is probally leaking out causing it to stick to the gears and slow everything up, cuz i don't think those diffs are sealed so you ran run most greases fine cuz they wont' leak out or if they do they're only like 3k oil so its not big deal, but 50k is gunna slow things up and its way more sticky

the lug

the diff is not sealed, all the lube will be leaked

ok so it leaked out and went on the tranny gears? and its slowing everything down because its thick? so what do i do take all of it out and just repack with grease? would that be better?

I get my stampede diff out of the package, give it a little bit of Lucas oil, and its smooth as can be, no binding

i run red car bearing grease in my diff and it works pretty good... leaks out but it doesnt bind stuff up like 50k would

You changed the pinion/spur gear ratio from 5:1 to 2.5:1 and the acceleration is suffering by comparison? Hmm, wonder why that could be. I think you'd better check your motor temperature.

You dont need to ever gear that high to get speed, i run 50+mph all day, with 18/90 and 45 minute runs times

50+ is easy to say/think. But in reality, it's probably 40. He said he used to run it at that high of gearing, and it's alot slower acceleration than it was before using the new lube. I say check your mesh,motor temp and then maybe bust the tranny open and relube with something else.

I didn't read the bit about previously gearing the truck that high initially; the wording was a bit vague in reference to "it". Anyway, mesh and gear ratio would still be the most likely culprits. I know that a 'sticky' lube will have some drag effect, but I've never seen the level of effect the OP described. I'd still like to hear some motor temperatures at the two differing gear ratios out of curiosity. It may be that it was overgeared initially at 31/76, but the stickiness of the lube or a gear mesh issue is pushing it over the edge at the 31/76 ratio and it's heating up, especially if anything other than speed runs on pavement were involved. It seems like a ridiculously shallow gearing to me, but that's JMO.

Oh buddy i no what im running a cars speedometer isnt off by 10mph, My pede can beat my buddys Vortec 4.3 2005 astro van to 70mph just about 110kph, 50mph is 5/8th throttle

If you're Rich: http://www.rc-monster.com/proddetail.php?prod=flm20010

Definitely it's over geared for anything other than speed runs. I wouldn't run it like that for off roading. But if it's noticeably different now versus before, then I'd say whatever has been recently changed may affect it now. Unless the motor is showing it's had enough of that high gearing all of the sudden. I don't own a vxl, so I don't know what kind of low end power it has when geared that high. My mamba setup actually has pretty good torque when Im geared high, though I've never been geared that high. If you're using a 2s lipo rather than a 3s, that would be noticeably weak off the line when geared high and would make it struggle and heat up.