project 3905 e maxx

[Rivermaxx]

You really think going 40 mph puts more stress on a tranny than gearing it to go 80mph? Yea that 80 mph pass upside down I hit a road reflector and it sent the truck flipping. Did you see the 75mph wheely? If any thing puts alot of stress on a tranny that should of done it.
I haven't tried those ti gears out yet and I only have about $40 invested in them (got them off ebay). I figured I would try them out when my others failed but havent come to that point yet. Your steel gears will most likely wear the same as those titaniums gears if they are not case hardened unless they have constant lube to prevent failure. Any thin light weight synthetic oil would probably be best. The thick sticky stuff will probably just slow you down and burn up your esc because of the trans acting like a hydralic pump.The biggest problem with those stock trannys is the shifting causes failures. Gorillamaxx saw this and adressed it with the single speed G1 conversion which pretty much make the trans bullet proof. With brushless power you dont need the 1st gear and its not really low enough to do real crawling anyhow. My other g-4maxx creeps pretty good while in second with the lower geared 1/8 scale diffs and 3905 revo tranny but I built it as a racer not a crawler.

These are my custom titanium gears( I believe only 5 sets ever made) with one UE gear(top left) that is in use now. Quite a bit weight difference between those and steel. Aluminum is the worst material to use for gears as you found out but the ultramaxx gears are made from a harder 7075 billet aluminum with a brass alloy idler and last forever with proper maintenence.


As far as the diffs failing do yourself a favor and put some 1/8 scale diffs in(like UE or FLM) and never look back. I broke stock diffs with nitro power all the time.

hi all...sorry guys i did not make myself clear, i have not just poured this thick lube in the box, i have just coated the cogs on all meeting faces with a few drops of the lube as thinner oil will not stay in the box.

rivermaxx, i agree with the rear pinion weakness but then again this truck is not designed for 5-6hp, the weakness is because the rear crown wheel and pinion are not cut correctly, if you magnify the rear pinion you will see the contact marks are on the outside edge only so the tourqe is taken by just a few mm of tooth, i am still using my original front pinion but my rear has been changed out for the newer 3906 due to failure. i weighed my truck and its 11.3lb not too bad seeing as its extended by 40mm . and yer there is alot of free play in the bearing even when they are new.

redshift, yes when you reduce the gearing you amplify the torque, thats how come i smash cogs and you dont, the problem i have is with the smaller 20 tooth cog. but seeing as i was splashing out on gear cutters, for another £40.00 i could make the 31 and 36 tooth cogs from steel as well. i dont crawl with my truck as id loose the will to live at that speed but i climb the biggest hill i can find and my truck is geared down with the spur so 1st gear is good to climb. those ti gears look wicked tho, i allways dip the throttle when i change gear to prevent damage, it tells you to do that in the manual.

sum pics of my latest venture to margate beach, bent a rear drive shaft and poped a front shock




bye all...

redshift...hows the mutant going these dayz? ment to ask, any new developments? just been watching some of your videos all you need now is some sort of self-righting thingy-ma-bob, maybe a hydrualic ram on the top hinge robot warz style, so it flips the truck up in the air and onto the wheels haha. oh and do you shim your rear crown wheel over in the diff? that will make it last a bit longer