Pro Tek R/C
Tru Torque 4-in-1
Nitro guys, you need one of these.
;ere’s an 8mm socket for glow plugs,
10mm socket for clutch nuts, 5mm
hex wrench to fit suspension pivot
balls, and 3mm hex for 3mm fasteners
(duh). ;ese socket and hex sizes are
also useful for working on quite a few
bicycle parts too, if that’s your thing.
The Diff-erence Between Oil and Grease
Can you explain why an oil-filled di;erential “unloads” less than a
grease-filled di;erential? Grease is thicker than di; fluid, after all.
For those unfamiliar with the term, “unloading” is the tendency for
a di;erential to send power to the wheel with the least traction. In a
grease-filled di;erential, the gears displace the grease, leaving
only a film on the gear teeth. ;e gears turn
very freely, so there’s little resistance to
unloading. Unlike grease, which stays
put once displaced by the gears, silicone
oil constantly flows back into the gear
mesh as the di;erential operates, so resistance
is consistent. So why aren’t all gear di;erentials
silicone-filled? One reason is the precision fit and seals required to
prevent oil from leaking from the di; increases cost and complexity.
;is is particularly true on an RTR assembly line, where properly assembling and filling a sealed di; is much more time-consuming. ;is is why
some RTRs have greased di;s even when equipped with di;s capable
of holding oil.
An oil-filled di; is less
prone to unloading, and
how freely it operates
can be tuned by changing fluid viscosity.
My transmitter’s steering wheel has no tension and no longer
centers itself. ;e car still steers fine, but I can’t believe how hard it
is to drive without that centering ability. Is there a fix?
You’ve got a broken spring inside the transmitter, and thankfully
it’s an easy fix. ;e only hard part is getting a replacement spring.
Contact the transmitter’s manufacturer to see if they have a
replacement. If not, you can substitute an orthodontic rubber band
or a craft store band. ;e precise steps to install the spring will vary
with your transmitter’s brand and model, but the basics are easy.
1. Remove the steering wheel and batteries.
2. Remove the screws from the back of the transmitter and open
3. Remove the circuit board to access the wheel mechanism. If you
can’t see the spring yet…
4. Remove the screws that hold the wheel mechanism.
Once you’ve accessed the wheel mechanism, all you have to do is
remove the broken spring (if it hasn’t already fallen o;) and slip the
new one (or a rubber band) over the spring posts.
Above: With the transmitter open and circuit boards out of the way, we can see the
trigger mechanism ( which has a spring of its
own) and the wheel mechanism—four more
screws will let us get to its spring.
Right: ;ere’s the steering wheel spring. An
orthodontic or craft rubber band can replace
a broken spring.