Rear Belt problems T3 12.

Scotty89 · **Joined:** Wed Nov 30, 2011 14:00:15 **Posts:** 12

hey,

at first sorry for my Engl. :mrgreen:

On the weekend we had a local race and i was relay god but had the problem was that the Car lost of lot of speed in the corner.
I change a lot in the setup but it would be better.
Next day at home i clean the car and search something it could be ....
all bearings are perfect and all move smoothly...

But i found some interesting thing on the rear belt.
On the picture you can see it the belt is going up and down... so it getting tighten on loosing.
the funny thing is that if you use the dif. in the front it makes no problems.
for testing i built in the spool in the rear :shock:

..... the same problem... the belt is going up an down.

I thing there must be a problem with the gearing of the belt. ?
(i test it with an old and an new belt.... and i use only original xray parts)

Sincerely

Scotty

Skiddins · **Posted:** Mon Jun 18, 2012 21:44:37

It looks like the belt is getting caught on something on the diff.

If you remove the rear belt and spin the diff does it spin nice and straight?

Is there any plastic swarf on the pulley.

Is it always happening at the same place on the pulley or the same place on the belt?

Skiddins

Matt W · **Joined:** Tue Apr 24, 2012 18:03:00 **Posts:** 82

Is that a standard spur gear or an offset one as if its an offset and you have it the wrong way around it angles the belt quite badly and does odd things!

Scotty89 · **Joined:** Wed Nov 30, 2011 14:00:15 **Posts:** 12

Skiddins · **Posted:** Tue Jun 19, 2012 10:29:53

Are you using an Xray rear belt or one from another manufacturer?

KevinBates · **Posted:** Tue Jun 19, 2012 12:41:54

Do you have both bearing holders in the same position.
Mine are usually down at the bottom for the belt tensioners not pointing backwards like yours on the photo.

Stanley Bąk · **Posted:** Tue Jun 19, 2012 15:56:31

why this belt is so loose?
tight it
as said before give it up(pitch down)

Sunnyho710 · **Joined:** Fri Mar 30, 2012 04:27:19 **Posts:** 7

I also feel that is too loosen .
Although it is new belt , no need to set
too loose like this.

Standard is the middle of bottom, I also
set in 2 point behind when it was new belt.

Scotty89 · **Joined:** Wed Nov 30, 2011 14:00:15 **Posts:** 12

hey,

it is an two race old belt (original Xray 305432) and if i tighten it, the belt will be very tight ( the car rolls no more of throttle

)

in the next days i will order an new belt for testing ...

Skiddins · **Posted:** Tue Jun 19, 2012 23:40:51

I notice from the picture that the parts that hold the pulley bearings are the wrong way around.

Part 302069
Could this be trying to push the bearing and create tension?

Skiddins

Scotty89 · **Joined:** Wed Nov 30, 2011 14:00:15 **Posts:** 12

hey,

right as i see there are wrong ... but if i install them in the right way its the same

there are no tensions

Skiddins · **Posted:** Wed Jun 20, 2012 23:28:15

Is it possible for you to take a closeup video of you slowly turning the rear diff concentrating on where the belt is being lifted?

Scotty89 · **Joined:** Wed Nov 30, 2011 14:00:15 **Posts:** 12

hey,

of course i can do at weekend.

CharlesF · **Joined:** Fri Jul 15, 2011 10:18:37 **Posts:** 35

This is a strange one!

Looking at it logically, it can only be:

1. Pulley out of line with the diff (i.e. the belt is trying to climb up the diff or pulley flange)
2. Pulley or diff wobbling - in vertical plane (up and down) or horizontal plane (side to side)

A close look and measure while spinning the respective pulleys & diff should reveal this ?

You say you have checked, but I have had intermittent belt tightening when a lump of carpet fluff has got caught in one of the pulley / diff tooth "valleys" (or less commonly in the belt). It's often black and not easy to see - maybe have another close look? Clean it out with a stiff toothbrush and brake cleaner.

Scotty89 · **Joined:** Wed Nov 30, 2011 14:00:15 **Posts:** 12

hey...

now i am at home and have an brand new belt ordered ^^

I have change the holders and install an brand new belt (in initial position), and see there it works perfectly.
Its an little bit crazy because the "old" belt is 2 races old and makes the problem....

thank you for your helps

XRAY - Model racing cars

Rear Belt problems T3 12.

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