# Tyco 440-X2 Drivetrain Tightness



## Grandcheapskate (Jan 5, 2006)

I was running a few of my Tyco 440x2 cars today. One car seemed a little "off" so I took a closer look. When I try to turn the rear wheels by hand, they turn very nicely in one direction and are quite tight in the other direction. Unfortunately, the drive train must turn in the direction which is tight.

I figure this must have something to do with the mesh between the pinion and crown gear. Even under a magnifying glass, the gears look in great shape. I tried a different rear axle and got the same problem - free in one direction and tight in the other.

I have no real experiance in diagnosing and tuning inline chassis. Is there another cause besides the pinion/crown mesh which would cause the drive train to be so tight in one direction? Is there a way to wear in the gears so they loosen up? Or is there another reason, like the armature may actually get "hung up" spinning in one direction?

Thanks...Joe


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## [email protected] (Jan 31, 2010)

Check the commutator. I had one delaminate on one spot and it turned fine one way but not the other. Although it did not bind as much as catch in that one spot. 

Are the motor magnets coming into contact with the armature?


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## Hittman101 (Oct 21, 2009)

The pinion might have moved and you might need to push it back some..


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## Grandcheapskate (Jan 5, 2006)

[email protected] said:


> Check the commutator. I had one delaminate on one spot and it turned fine one way but not the other. Although it did not bind as much as catch in that one spot.
> 
> Are the motor magnets coming into contact with the armature?


"Catch" is a good word to use as it does seem to catch in one spot. However, it seems to "catch" when I turn it in the loose direction. In the other direction it is just a whole lot tighter.

Do I have to disassemble the chassis to check for any delamination? From what I can see, there doesn't appear to be any problem with the arm.

I also don't see it hitting the magnets, but it's impossible to tell. I have tried moving the crown and gear saver. The pinion is positioned just right. Nothing changes for the better.

Thanks...Joe


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## jobobvideo (Jan 8, 2010)

try a lifelike rear end? change the pinion? worn comm brush?


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## 1976Cordoba (Sep 20, 2000)

My gut says you have a flat spot on a gear tooth.

You could burnish down the egdes on the comm, but I don't think you'd notice a high spot there unless it was way out of whack.


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## slotking (May 27, 2008)

do u have a 9nolt battery

turning the wheel by hand is misleading, because the wrong face of the gear teeth touch.

you have turn the arm

try a 9volt battery, listen to it, then reverse the battery so it run the other way and listen
what sounds better?

I would also inspect the teeth with a magnifier, look for bent over teeth or missing teeth.

watch the arm shaft and the axle, make sure both are straight


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## Grandcheapskate (Jan 5, 2006)

I had my mechanic look at it tonight and he believes the pinion gear may either have a high spot or be a little off center. I'll either replace it or just let it wear in - it's only a runner.

Thanks...Joe


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## Hornet (Dec 1, 2005)

Flip the magnets and the axle around and run it backwards.

Mike's right,finger spinning the tires loads the wrong side of the gears.


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## Pomfish (Oct 25, 2003)

Since it is a runner try this, run the chassis with a 9 volt battery and put a lighter flame up under the gears while they are turning.
Not for a long time mind you, you will hear the pitch change as the gear softens and resets to the other gear. As soon as you hear that pull the flame away.
Got that tip from Ed Bianchi and it has worked for me in the past.
good luck
later,
Keith


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## slotking (May 27, 2008)

afraid of fire, do the same with an soldering iron

SEE VID
http://ho-tips.net/showthread.php?tid=1630


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## LDThomas (Nov 30, 1999)

Grandcheapskate said:


> I was running a few of my Tyco 440x2 cars today. One car seemed a little "off" so I took a closer look. When I try to turn the rear wheels by hand, they turn very nicely in one direction and are quite tight in the other direction. Unfortunately, the drive train must turn in the direction which is tight.
> 
> Thanks...Joe


Remember, when rotating the wheels by hand, rotating them backwards meshes the gears with the same faces that mesh when the pinion drives them forward. If the friction is in the gears, the situation described above is OK.


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## Grandcheapskate (Jan 5, 2006)

Guys....thanks for all the tips.

Joe


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## slotking (May 27, 2008)

> Remember, when rotating the wheels by hand, rotating them backwards meshes the gears with the same faces that mesh when the pinion drives them forward. If the friction is in the gears, the situation described above is OK


yes, but the torque is from the wrong side (crown pushing the pinion) to really see it has to be the other way around from my testing gears


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## Bill Hall (Jan 6, 2007)

Joe,

Pretty normal, the gears get worn-in in the primary direction of travel. As stated, your contacting the gear teeth on the backlash side when you finger roll the tires. You may have to ease the lash a little... or/and 

1 lighter trick
2 toothpaste lap in reverse
3 toothpaste lap in forward
4 clean up
5 go racing

Lapping the backside is frequently over looked, but makes for a smoother chassis off throttle/decel.


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## slotking (May 27, 2008)

or put in fresh gears:wave:

But you can add a few spacer behind the crown gear to to reduce how far the crown travel away from the pinion or if it has the gear boss, use that to reduce how far the crown can pull away.

or try new gears from Slottech or the other companies


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## alpink (Aug 22, 2010)

wondering why the world's most interesting and biggest TYCO fan hasn't weighed in here with his expert advice on how to solve this dilemma?
stay thirsty friend


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## LeeRoy98 (Jul 8, 2005)

alpink said:


> wondering why the world's most interesting and biggest TYCO fan hasn't weighed in here with his expert advice on how to solve this dilemma?
> stay thirsty friend


ROFLMAO... yeah, maybe he is out quenching his thirst??


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