Diff out drives tight to turn

[shortyloz]

Hello all

On my sons Granite 4x4 Mega, the rear diff out drives are very difficult to turn. I stripped the Diff, greased and all is OK until I reattach the bearing for the case as shown in the picture. Then the out drive on one side is very difficult to turn. It's like the bearing is squashing the plastic.

Is this "normal" or has somehow the diff casing become damaged?

When I then checked the front diff, it was exactly the same. Suggesting this is normal.

When the car is assembled and I try to spin the wheels in the air with my hand, they do not freely rotate. I'm sure they should spin quite freely.

Thanks
Mark

 

[Yas]

You may have overtightened the splined axle screw(s) that thread into the diff gears. They should be thread locked and hand tightened until they're snug

If the diff is tight after fitting the diff into the yoke (make sure you're fitting it the right way round), the bearings may not be seated properly. The pinion ones are usually difficult to seat as they fit very tightly on the pinion shaft

You may need to shim the diff. I found my Typhon 3S' diff pinion/ring gear mesh from factory was too tight, so I had to add my own shims. I think these were 15x18x0.2mm but I'm not sure

The only other thing I can think of is the oil you filled the diff with is thicker than the 10k cSt it comes as stock

 

[shortyloz]

Thanks for the suggestion on the tightening. I think it has the issue prior ti tightening, but will recheck. On the Mega the diff's appears use grease not oil.

 

[vader]

Make sure you haven’t over tightened the diff case , from the pic it looks like the gasket is being squeezed too much , this will make the input gear rub on the diff case

 

[biggman100]

Hello all

On my sons Granite 4x4 Mega, the rear diff out drives are very difficult to turn. I stripped the Diff, greased and all is OK until I reattach the bearing for the case as shown in the picture. Then the out drive on one side is very difficult to turn. It's like the bearing is squashing the plastic.

Is this "normal" or has somehow the diff casing become damaged?

When I then checked the front diff, it was exactly the same. Suggesting this is normal.

When the car is assembled and I try to spin the wheels in the air with my hand, they do not freely rotate. I'm sure they should spin quite freely.

Thanks
Mark

I have had the exact same issue as you, not once, but on 3 separate occasions. I always end up replacing the diff case when it happens. I haven't figured out what exactly causes it, but, this time i got a new diff, and rubber shielded bearings. Once i get it together, i will see if it does it again. I also had a V1 Mega Senton that did the exact same thing. The only thing i can think of that might cause it is heat in the bearing causes it to swell just enough to cause this to happen.

 

[shortyloz]

I have had the exact same issue as you, not once, but on 3 separate occasions. I always end up replacing the diff case when it happens. I haven't figured out what exactly causes it, but, this time i got a new diff, and rubber shielded bearings. Once i get it together, i will see if it does it again. I also had a V1 Mega Senton that did the exact same thing. The only thing i can think of that might cause it is heat in the bearing causes it to swell just enough to cause this to happen.

OK, and replacing the case has always solved your issue? Okay I will order 2 of those then.

 

[biggman100]

OK, and replacing the case has always solved your issue? Okay I will order 2 of those then.

Replacing the case only solves it short term. After awhile the problem comes back. Someone local that i know suggested upgrading to the newer V3 diffs, but i don't know if that will help it or not.

 

[Camaroboy383]

Hello all

On my sons Granite 4x4 Mega, the rear diff out drives are very difficult to turn. I stripped the Diff, greased and all is OK until I reattach the bearing for the case as shown in the picture. Then the out drive on one side is very difficult to turn. It's like the bearing is squashing the plastic.

Is this "normal" or has somehow the diff casing become damaged?

When I then checked the front diff, it was exactly the same. Suggesting this is normal.

When the car is assembled and I try to spin the wheels in the air with my hand, they do not freely rotate. I'm sure they should spin quite freely.

Thanks
Mark

View attachment 125550

I beleive there is far to much thought put into this.. they are all far from a precision machine.. run it... there will be no ill effects.. most if not all add thicker fluid to the diff internals because they are to "loose"..

Remember when the rig is assembled and the wheels are on it.. that action now has more leverage than open 8mm shafts in your fingers.. .. if the diff action is there it's fine, when it locks up full posi, then you have an issue inside, or a spool..

 

[biggman100]

I beleive there is far to much thought put into this.. they are all far from a precision machine.. run it... there will be no ill effects.. most if not all add thicker fluid to the diff internals because they are to "loose"..

Remember when the rig is assembled and the wheels are on it.. that action now has more leverage than open 8mm shafts in your fingers.. .. if the diff action is there it's fine, when it locks up full posi, then you have an issue inside, or a spool..

The Mega vehicles have grease, not oil, in the diff, and no O-rings to keep the oil in the diff. Been there, done that, and it took 2 days of disassembly and cleaning to get all the oil off everything, then it all had to be reassembled.

EDIT: After looking at the V3 Mega diagram, they do have O-Rings in the diff. My V1 doesn't though.