So it begins (Frog Noises)

[Kowalski86 3034]

While running my Frog one of the rear axles has started to make some awful noises on acceleration, I can only guess this means that the hex end on that side has given up. Is it advised to replace them with dogbones or universal joints? The difference is just $10 so I don't mind going with universals if thats the better pick. Other than that the cars held up well all things considered.

[Frog Jumper 3662]

I've had good luck with the Frog Dogbones and use them on a couple of my ORVs.

But that clicking sound is likely your trans gears slipping?  Do you have a transmission brace???

Terry

 

[Kowalski86 3034]

15 minutes ago, Frog Jumper said:

I've had good luck with the Frog Dogbones and use them on a couple of my ORVs.

But that clicking sound is likely your trans gears slipping?  Do you have a transmission brace???

Terry

 

I have a brace and I tightened it down carefully as to not over tighten. My gearbox was very warm at the time.

For a time I was running a Sport Tuned and a Nimh, but it started to act up after I installed an old (slower) "Twister" motor. I could go back to a silver can to be safe.

[alvinlwh 5895]

On my brand new rere Frog, it spit the dog bones out within its first 20m. Your chassis is probably older and looser so I am not sure if they will be any better. There are various mods/adjustments that one can make to prevent the dog bones from popping out but what I found that fixed it is to use the very expensive CVD set.

[Kowalski86 3034]

@Frog Jumper

I tightened the brace down, went back to a silver can, and installed one of those fiber discs between the transmission and the motor.

So far no transmission trouble, I need to tightened up the front drivers side hub but everything else is good.

I've theorized that both the vibrations from the motor and heat contribute to the transmission not holding together well, the motor side aluminum basically acting as a heat sink.

1 hour ago, alvinlwh said:

what I found that fixed it is to use the very expensive CVD set.

Hopefully it won't come to that, it is expensive but not much more than new dog bones (for some reason).

[Saito2 6686]

My findings over the years mostly corelate with  Frog Jumper's. Despite their infamous reputation in US RC print media BITD, skipping/clicking diff gears tended to be more of and issue rather than the hex-headed half shafts RC Car Action often bemoaned. I have had better overall luck with re-re Frog dogbones than the uni shaft set. I noted this when I went through a Blackfoot build:

 

"The right rear uni shaft is much closer to the edge of the drive cup/outdrive. With trailing arm flex and the increased leverage provided by the larger monster tires, that shaft can pop out. I never read about complaints from those who used the uni shafts with Frogs (the uni shafts were originally a hop-up for the re-re Frog) so perhaps the tires are much to blame. I tried everything to get them to work. Shimming the backside of the stub axle inward can only go so far before the pinned wheel adapter starts thrust loading the outer bearing  in the trailing arm."

 

 

Now, like I said in the earlier thread, the uni shafts might work better in the smaller-tired Frog. I will say, I never spit out dogbones on my re-re Frog when using the rather stiff, stock oil shocks. When I installed some more compliant, properly damped CVA shocks as a test, the dogbones did pop out almost immediately like alvinlwh experienced.

[Kowalski86 3034]

5 hours ago, Saito2 said:

My findings over the years mostly corelate with  Frog Jumper's. Despite their infamous reputation in US RC print media BITD, skipping/clicking diff gears tended to be more of and issue rather than the hex-headed half shafts RC Car Action often bemoaned. I have had better overall luck with re-re Frog dogbones than the uni shaft set. I noted this when I went through a Blackfoot build:

I'll keep that in mind then should the hex shafts wear out, I plan on sticking with the stock shocks and sticking to a silver can so hopefully everything will hold together!

[Toolmaker72 507]

Just to add my experience.  Using a gearbox brace and original hex drive shafts I’ve been running a 3930kv motor with 3s lipo and nothing slips or clicks.  I then built another car using a lower powered 2s battery motor combo and the dog bones pop out instantly over bumpy ground.  To also note the hex drives are hardened steel and last a very long time if kept clean and well lubricated.  Picture of hex drive car below.

 

 

[Kowalski86 3034]

5 hours ago, Toolmaker72 said:

To also note the hex drives are hardened steel and last a very long time if kept clean and well lubricated. 

Good to know, a part of the reason why I chose an original model was to avoid the dogbone/universal stuff.