Kyosho mp9 tki4

[Mikespaniel]

Hi everyone, could someone help me please. I've got a fairly new mp9 tki4 and have noticed that the center diff moves back and forward as in front of buggy to back back of buggy. I took out the center diff and nothing seems obviously wrong apart from it just moves in the housing that screws to the chassis. Does it need shims or something or is this normal?
Thanks Mike.

 

[cbaker65]

Hi everyone, could someone help me please. I've got a fairly new mp9 tki4 and have noticed that the center diff moves back and forward as in front of buggy to back back of buggy. I took out the center diff and nothing seems obviously wrong apart from it just moves in the housing that screws to the chassis. Does it need shims or something or is this normal?
Thanks Mike.

I have that buggy ,I just got it an only has had 2 tanks of fuel ran through it ,an I just checked
my center diff on the play!
Mine only moves just back & fourth very little ,it moves about the width of a sheet of paper ,so
if that is all yours moves ,then I wouldnt worry about it as you may need just a tad of free play
so that it allows for fluid pressure expansion ,an the diff to breath while at high speeds an loads!..

 

[Greywolf74]

If it moves more than that then yes you may want to try shimming it up

 

[Mikespaniel]

I have that buggy ,I just got it an only has had 2 tanks of fuel ran through it ,an I just checked
my center diff on the play!
Mine only moves just back & fourth very little ,it moves about the width of a sheet of paper ,so
if that is all yours moves ,then I wouldnt worry about it as you may need just a tad of free play
so that it allows for fluid pressure expansion ,an the diff to breath while at high speeds an loads!..

Mine moves more than that. It doesn't mention anything in the manual about shims and is assembled as per the manual so i can't see what else i can do. I will just keep using it as it is. Thanks for looking at yours for me.

If it moves more than that then yes you may want to try shimming it up

Can you buy the shims especially for this purpose?

 

[cbaker65]

Mine moves more than that. It doesn't mention anything in the manual about shims and is assembled as per the manual so i can't see what else i can do. I will just keep using it as it is. Thanks for looking at yours for me.

Depends on where the play is at ,is it coming from where the bearing sits in center mounts or
is the output shaft itself have the slop ,there isnt much room in between the bearing mounts for play!

Ok ,just looked an there seems to be an o-ring inside the center diff on the output shaft ,my guess
is if those are worn ,it may cause slop in the output shaft!

I didnt build my kit ,as the previous owner did ,but when I looked in the manual ,as the output shaft
goes in ,then an o-ring goes on to the shaft before the pin an gear goes into place ,if that o-ring was
not installed or if it is worn out ,then it will have slop ,so I would pull it apart an replace the o-ring or
if the o-ring seems to be good ,try a thin shim on top of o-ring to take the slop out!..

 

[Mikespaniel]

I thought it was coming from where the bearing sits in the center mount. But i will double check now you have mentioned the o ring.

 

[cbaker65]

I thought it was coming from where the bearing sits in the center mount. But i will double check now you have mentioned the o ring.

If you open that diff ,an remove the fluid to fix the issue then you better decide what weight of fluid to
use now while you have it apart!..

 

[Mikespaniel]

I've got the diff in my hand now and the problem is both bearings are moving a lot on the shaft. Thats what is causing the movement. Now i havent got a clue what to do. Chuck it in the bin and buy a new one unless someone knows the answer. Its not even that old.

 

[cbaker65]

I've got the diff in my hand now and the problem is both bearings are moving a lot on the shaft. Thats what is causing the movement. Now i havent got a clue what to do. Chuck it in the bin and buy a new one unless someone knows the answer. Its not even that old.

Is the bearings seem good ,or is the mounts wollowed out were the bearings ride ,because those are easy to be replace?
As far as the output shaft that comes out ,you would need to check for back & fourth slop in that!

But if the bearings & the bearing mounts are intact ,you can still put a shim there as well right where the output
shaft goes through the bearing an on to the mount itself to take the slop up there!

 

[Mikespaniel]

Is the bearings seem good ,or is the mounts wollowed out were the bearings ride ,because those are easy to be replace?
As far as the output shaft that comes out ,you would need to check for back & fourth slop in that!

But if the bearings & the bearing mounts are intact ,you can still put a shim there as well right where the output
shaft goes through the bearing an on to the mount itself to take the slop up there!

Ok that explains it well. I shall try exactly what you say. The bearings and mounts are good its just the bearings moving on the shaft. The front shaft has about 1- 2mm of play the rear is ok so looks like some shims are needed . May as well replace bearings whilst its out.