i just got an MT2 yesterday. im new to the RC car thing, so i figured it would be a good car to start with.

break in went well, but after only 30 minutes of total drive time, i noticed it wasnt steering very well or braking well. i read on this board about the braking adjustments i can make, but the steering had me worried. it made a clicking sound as the servo operated.

i opened the servo and sure enough, the smallest gear was half stripped. i dont know what i did to trash the gear, but either way its broke. do i replace this with another stock one, or should i get a different kind of servo? i just want something i can drop in and start driving the car again with. what do i do?

DONT GET THE STOCK ONE!!!!! they always break they are crap. get a high torque futaba or hitec...they are so much better. i would get a whole new radio too.

Im using a Protech B515 BB MG, cost me £25, and it turns tmaxx wheels fine. I have heard of the hitec ones having probs with centering, and also loosing teeth from the gears. My 2p....

Hitec 645mg on mine with no problems other than it is a little slow which ins't necessarily a bad thing. Steering servos are usually one of the first upgrades that should be done. If the truck is still under warranty send the broke servo back to CEN and get it replaced and use it for a spare for the throttle/brake servo. It's always good to have extra servo's kicking around.



rolland

CEN has 10kg servos with metal gears which are available from your local CEN dealer. As with ALL standard servos which have plastic gears, hitting objects or landing with the wheels in a position that will apply pressure to the servo can eat teeth. Send your problem servo to

CEN/GTC
Customer Service
1800 E Miraloma Ave. Suite F
Placentia, CA. 92870

Discribe what the problem is, and if they determine that the problem was with the servo, they will warranty it. I personally use the CEN 10kg servo for throttle and break, and aftermarket for steering, but hey I race a Genesis.

it sounds like the higher torque servos are the way to go. the only question i have now is this -- which ones are direct drop-ins?

is the 645mg a direct drop in? do i need to get a different plug or anything? which throttle servo should i use?

The 645 will replace the stock steering servo. Just make sure that you use one of the screws that come with the servo. The worse that can happen is that you might have to flip the servo reversing switch on your transmitter. I use the stock CEN servo for the throttle and the bake and have had no problems with it at all.
The 645 will drain your batteries slightly faster so you should upgrade to a rechargeable 6volt pack.


rolland

well, i got the hitec 645mg servo today, put it in, and it did well. after about a half a quart of fuel, however, i split a differential cup.

i was driving it in the grass at WOT, and i never hit anything at all. that design is piss poor. i guess ill order some more. what is the best online place to order them from, and what part number are they listed under?

GX 12 try here http://www.rcmodels.com/parts-depot-cen.html or here http://www.toyhaus.com/ . Do a search for the diff cup mod here in the CEN forum. This mod is almost mandatory and greatly increases the life of your diff cup.



rolland

The Goat... if you are WOT in tall grass you will put too much strain on the diff cups as well as the engine eventually.. The diff cups are meant to be the weak link in the system so they will break before more expensive components fail.. I have forund that the best way to keep them longer is to make sure that the dog bones and cvd are in correctly and to the right depth.. also, I lowered the ride height of the truck and guess what, no more broken cups.... I now break cvd pins instead, but thats another story..

what is the proper depth, and how do i lower the truck cost effectively? the grass i was running in wasnt high, it was freshly cut. still, it took alot of throttle to get the truck moving in it. once it was moving though, it was really doing well. i still have to get the tune right.

i read about the mod in another thread. id rather not use brass or (or the soft ferules used in compression fittings). ill probably put a piece of stainless steel in the lathe to knock down the o.d. and use a drill for the i.d.

btw, since im going to run it in the grass more than anything, would the larger cooling head help? i know how to tune an engine (i build engines on the side and my day job is rebuilding industrial diesels), so id just like to keep the temps down, but i heard somewhere that the oversize heads dont allow ENOUGH heat to build in the engine.

the oversize heads will help... my nt-16 in tall grass would easily peak over 300 on a warm day... this won't necessarily hurt the engine as long as your not leaning it out... make sure for good smoke... I run an oversized head on one of my trucks with a .21 nitro star in tall grass and it is fairly cool... mid 260's WOT, but it is more of a hassle to tune... the cen oversized purple head looks good and runs well but tuning is a bit more difficult to set... I now run the os .18 cv and temps in med to low grass only 240-250 with wheels pointed to the sky...
as far as a cost effective way to lower chassis, try using small piece of fuel tubing inside the shock to limit the length.. i used about 1/3 inch and lowered the height to where the dog bones and cvd's were parallel to the ground... (control arms were straight out) keep in mind this limits jumping unless you change to a stiffer spring and or change shock piston rate and fluid... I experimented and found that a #1 shock valve and 30 weight oil with a med spring works for the best balance overall... just don't sky the truck off huge ramps...
Per Cen Racings advice, I stopped using the diff cup mod and spent more time adjusting the suspension geometry and found that I don't break anymore diff cups and also, the dog bones and cvd's are lasting longer.. I was breaking cvd and dog bones with the diff mod... The diff cups are designed to break before the more expensive dog bones and cvd's even though they should last longer... hopefully they will eventually come up with a stronger cup design...

i appreciate all the help, bud. im new to this, so bear with me.

since i primarily drive the truck in grass, id like to maintain a little ground clearance, but i want to reduce the angularity of the drive axles to save the cups. ill put the spacers on the shocks, but if i step up my tire size get my ground clearance back, is there an approriate drive gear out there to give me my final drive ratio back?

btw, what head do you suggest?

your not losing enough clearance to need larger diameter tires besides you will find out you can't easily get different tires for the mt2... it is one of the only mt with 2.2 rims.... I am working on an adapter to fit t-maxx tires on larger hexes and poor judgement has a thread with an exle change which looks good.. I run mine in grass all the time and no problems with clearance... If you are really going to run in the grass exclusively, change to a larger engine... .18 to .21... you will kill the nt-16 eventually.... If you want a larger head, Cen racing makes a Purple Head which is much taller for more cooling.... Hope this helps

CEN posted somewhere that the new diff cups a supposedly stronger than the old ones.

I use the diff cup mod and have never broken a diff cup, dog bone, or cvd. Here is what I did for the mod. I used some brass tubing the same diameter as the diff cup, heated it up and resized it so that I had to press it on and used a screw driver and some more heat to re-open the gap in the cup because during the pressing process it closed slightly. But I probably would have done something different if I had access to a lathe.



rolland