The whole hog

[DOGPILE]

Ok, sorry about this guys, its a repetetive problem that i can't seem to cure even with your always valuable help. Diff, need i say more.

I have Rebuilt both the front and rear with all new diff cases and bearings along with the diff gears and 4mm ofna cross pins for the spider mod.

Have also stripped the trany and found no faults.

Loosened the slipper to the point where the truck would just sit there and not move then tightened a quart at a time until i reached the bite point then added another 1/4 turn.

Replaced all the drive cups and shafts with HPI heavy duty so there is little or no slack in the drive.

Used 8000wt oil in the front and 10000wt in the rear.

Also added a new pipe.

The truck flies like s**t off a stick, its a completely different truck, its ace, i love it, BUT

Question yet again.

Why does my rear diff only last for about 5 mins everytime i take it out. HELP AGAIN PLEASE

Also i am getting very poor because of all the stuff i have to keep replacing, including wheels from my last 5 min session.

 

[alkyula]

are you running a picco? maybe the heavy oil your running in the rear is limiting the diff action alot, on top of a lot of power, and alot of traction, putting alot of stress on the rear diff. maybe next time try inferno 7.5 diff cases, I've read they are stronger than the hpi diff cases, and also use some machine screws insteadd of the stock self tapping. also did you do the 4-spider mod with hpi bevel spider gears? they seem to be of the best quality, more so than the ofna ones at least.

 

[Puffnstuff]

Ok I've had problems myself with the rear diff letting go. After I did the 4 spider mod the self tapping screws backed out ruining the holes in the cup. After I fixed that the bearing on the ring side let go allowing the pinion to skip the ring gear. Well I replaced that bearing and said that enough was enough. I ordered alloy diff cups from tower along with alloy gear boxes to there won't be any movement to allow the gears to skip and break teeth off. I've also had a problem with my wheel hexes rounding out even with the improved hpi hexes and loctited nuts. I've ordered gpm hexes and have moved to proline wheels in hopes that they'll hold up longer to the power of the mach. If they don't then I'm going to alloy wheels because swapping wheels is getting old. I used kyosho bevel shafts when I did the spider mod and the last time I filled my diff with vaseline instead of grease in hopes that it will hold up better. I'm not sure what I'm going to use in the alloy diffs because I don't want to go back in them for a very long time after I build them.