GRU help?

[Jeepiac]

I put a set of Trepadors on my Mog, and you already know the chain effect that created. Pretty sure I'll end up putting a gru on it, but I can't find a HPI anywhere. Does anyone know who sells them, or if the RC4WD gru is any good?


As you can see, these tires are a bit on the tall side, but I like em
And they're a little closer to scale imo, but with bigger tires as you know the already high gearing really shows it's ugly head!

[Absurd]

I own a 2:1 and a 4:1, as well as a few planetary trans none have failed me, however I know others have had issues, over the time reading for which g.r.u. to pick a 4:1 is great with a 35 - 55T

[fla_cracker]

I use the HPI unit that I got off of amazon. It was only like 25 bucks. I have been using it for a couple of months now with no problems.

The only down side to the hpi unit is the noise. It is a little loud but kinda sounds like a turbo winding up, or a vacuum cleaner. Just depends on your ears....lol

But it crawls like no other!! Control like you wouldn't believe. I run a 17 turn brushed and it does slow walking speed. Which is fine for me.

Good luck...

[Jeepiac]

Awesome! Thanks for the help, guys. Just found a HPI on Amazon for just a few cent shy of 25 bucks. As for the noise, the CC-01 gear train is to damn quiet anyway. With a little bit better gearing this thing may become my favorite crawler!

[Jeepiac]

Alright, I got the GRU put in today and with a 27T motor it runs about 4-5 miles and hour with a 16 tooth pinion. A little slow, but the torque is awesome. Now for my new problem... The gear that hooks to the rear drive shaft is slipping under a heavy load. I pulled the top off the tranny and all looked good. I made sure the cover is completely seated, and I pulled the cover off the bottom and found nothing there either. Gears look fine and seem to be meshing pretty good. I had heard a pop once before and had forgotten about it till today, so it's nothing new, just amplified 10x over now that it's making tons of torque.
Is this a common problem, or just my chitty luck!?
Also, at this time the gears look fine. Not showing any signs of stripping.