Brushless RC18T Problems.....Need some HELP!!

smarking1212 · 02-21-2009, 03:06 PM

I just put a mamba 6800 motor in my rc18t and unlike the xray m18t pro I have w/the tekin mini rage system in it, the rc18t sounds gritty. Still has the pickup, but the gritty sounds are getting me worried. Maybe the diff's need to be upgraded or the spur needs to be changed to a metal spur. What upgrades will I need to make and will a metal spur gear just do more damage to the diff's. Thks

nutz4rcyktw · 02-21-2009, 06:43 PM

Have you checked to see if your diffs need to be tightened? When was the last time you rebuilt them? More power means more stress on diff.

helibrian · 02-22-2009, 04:30 AM

Quote:

Originally Posted by nutz4rcyktw

Have you checked to see if your diffs need to be tightened? When was the last time you rebuilt them? More power means more stress on diff.

+1

could just be the diffs slipping.

trerc · 02-22-2009, 04:38 AM

By "gritty" I assume you mean a clicking sound..? The diffs likely need shimmed, and don't waste you time with metal spur gears. They do look nice if you don't actually plan on driving the truck.

smarking1212 · 02-22-2009, 05:08 AM

I'm thinking metal input gear all the way around. Can you explain shimming? whatcha think

smarking1212 · 02-22-2009, 06:23 AM

I tried to loosen up the gear mesh and try another run. Well, the car moves but the spur and wheels feel tight to the turn. The car's diff's sound and feel like there locking up. I'll open the bad boy up tomm when I get time and see the damage. Just suprised how fast all of this happened w/ the new mamba 6800 system. Not one issue w/my xray m18t pro. If someone can shoot me pointers at what to look for when I look at the diff, that would be great.

trerc · 02-22-2009, 06:44 AM

You more than likely discover that not only did the diffs need shimmed (grinding clicky noise) but they were ran too loose and you gave melted the out-drives to the main gear (why they feel tight). Here's a link to the diff shims http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJZH4 start with 2 shims on the gear side of the diff. Properly built and shimmed diffs should have no problems standing up to a 6800kv set up.

Deves · 02-22-2009, 09:03 PM

A few years ago I built one of these trucks from the ground up with all the bling, everything that could be aluminum was , I had steel diffs installed and properly shimmed. This truck was a rocket! I also was using a Mamba 6800 in mine.
I built this truck for onroad use and won a few races before I started taking off the aluminum parts to run some off road with it.

After a fire consumed 99.8% of my garage in '07 A couple of weeks after I was rumaging around in the debris and I found a slightly melted plastic box that contained a couple of steel outdrives and a bunch of aluminum parts for the truck. I have front and rear arms and I don't remember what all was in the bag I put them in. If you guys know of anyone that might be interested in these parts have them PM me. Thanks

drperry · 02-22-2009, 11:26 PM

Diffs are probably need some work now...

I got lucky with 18MT RTR, and all the gears and diffs are still bone stock and 3-ish years old, 2.8 years running the 6800kV mamba system

Make sure your diffs aren't tightened too much... Mine did the same thing when I was doing adjustments and accidentally tightened the rear diff too much.

smarking1212 · 02-23-2009, 07:27 AM

Ok, heres the deal. I took it aparts and loosened up the diff which is a ball diff w/ the diff shims already in there. Worked out great. I am thinking about the aluminum spur gear and metal input gear. Thank god I didn't melt the diffs. I'll get pics up tonight of both of my 1/18's

drperry · 02-23-2009, 12:15 PM

Stick with the plastic spur, it'll be quieter, and lighter.

I'm still running my original spur gear.

All you need is to find or make a gear cover to keep the dust/rocks out, and it'll last, as long as your pinion/spur mesh is good.

smarking1212 · 02-23-2009, 01:49 PM

My spur gear looks like a hack job at a dollar store barber now.

Its all good. I forgot to say I'm pushing 2100 mah Thunder Power Lipo's. Its no 3 cell pack but man they got puch!

drperry · 02-23-2009, 01:59 PM

Dust and rocks will do that to the gears

I had a 2500 mAh max amps pack in mine for the longest time... Sucker moved GOOD.

smarking1212 · 02-23-2009, 04:54 PM

Here are some pics. Xray M18T pro has the tekin mini rage 6.8 system and the rc18t has the mamba 25/6800 system. Enjoy!

Deves · 02-23-2009, 07:44 PM

Here's a few of mine before it was destroyed in a fire..

All of the aluminum parts you see are for sale..
They were all removed prior to the fire..