What is ticking!
 

I have been having a persistant problem with my Cen Matrix Tr. Under moderate to hard acceleration and the hardest braking something in my drivetrain clicks! I have replaced everything in the rear driveline.. Entire new diff, retightened every screw and it still clicks. Checked the center diff and its fine but it still ticks! Thought it was a stripped wheels hexes and tried other wheels still ticks.


any ideas?

Checked all the driveline pins and bearings?

Its your biological clock........

it's your front diff. shes on the way out. the ticking under hard braking is a dead giveaway.

so why does it click under acceleration!? i replaced the front 2 weeks ago- everything is new. Under low braking there is no clicking.

went through and checked bearings and everything spins free




Did i mention it reduces power to the wheels drastically under throttle

The rear end experiences greater load than the front under acceleration, and the front end is loaded up more under braking. Have you checked the bevel gears in the front diff? Maybe it needs better shimming?

I had a strange clicking on my buggy one time. It was one of the suspension mount screws, it was too long. Under light loads it was silent, but heavy loads would make the diff outdrive move (deflect) enough to contact the end of the screw sticking up.

I spend an hour just now trying to figure this thing out. re assembled the truck as is with my spare diff. Truck acted as if re entire rear driveline was disconnected from the driveline But it was quiet. Then i took the rear apart thinking that the shimmoing on the ring/pinion was too tight- removed two shims and the clicking returned. Then i quit while I was ahead and came inside.

This leads me to beleive that the case on my spare diff is slightly longer then that of the original. so it requires the pinion to be closer to the case. but when moved closer to the case it binds on the outside of the diff housing evident by the wear marks. but any less shim behind the pinion results in a loose mesh and the diff clicking.... I think.

SO. What I plan to do is order all the parts that went bad for the original diff and reinstall it into the truck... That should resolve the problem... I hope.

Well i fixed the rear diff.. shimmed and set.. checked the front diff... the internal gears had some wear so I replaced those.

AND THE DAMNED THING STILL TICKS!

I am out of options.

Please tell me whats wrong!

Here are my possible problems and solutions
- Stripped wheel hexes, tried different wheels
-Rear diff gear mesh, re shimmed, replaced unit, shimmed again
-front diff, replaced unit-twice checked mesh. still nothing
-Center diff failure- found that crospins were worn, replaced them still ticking.

whats next?

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check the outdrives where the pins from your driveshafts ride. a grove will cause binding and a tick like sound sometimes under load. its happened to every r/c ive raced. either that or i am crazy. recently this happened to my rc8, didnt notice it until it spread one of the rear diff outdives and snapped it in half..... first lap

DId your Rc8 occasionally lose drive to the front or rear?

Still sounds like a slipping diff. Are the bearings good on the diff pinions? Worn bearings can allow enough deflection for the gears to get past each other. Any cracks in diff housings? Worn housings can do the same.

Housing is new. gotta check the bearings. I really hope it is something that simple.

not sure of your trucks designs, but could it be the diff housing is flexing like the maxx?

my maxx makes the SAME noise unless im running 60% punch on low start...and im pretty convinced its the case flexing

Whenever I replace a diff, I generally just replace the whole thing (go buy a brand new diff off ebay).

This way, it solves any diff issues there may be. Because a bearing issue can even be the cause for the gears going, or a case flex issue from an old fatigued case, etc. So I just replace the whole thing to be safe.