Center diff spur gear rubbing on the chassis

[-Dusty-]

Yep ended up blowing a bearing. Going to put stock bearings back in and see if it helps

 

[bicketybam]

Yep ended up blowing a bearing. Going to put stock bearings back in and see if it helpsView attachment 21797

If whatever’s caused that isn’t rectified, the stock bearing will be toast even quicker. That bearing looks annihilated.

 

[-Dusty-]

I just want to see if there is any play. It was way too tight and I just want to see if the stock bearings are slightly thinner.

Im not sure though. There are a couple things I think that might be wrong. Could be one of the holes in the chassis that is causing this problem (from that time i had to drill out the motor mount screw) or if the chassis is slightly bent in the middle.

Could also be that HR diff mount, who knows. I'll figure it out.

 

[bicketybam]

I just want to see if there is any play. It was way too tight and I just want to see if the stock bearings are slightly thinner.

Im not sure though. There are a couple things I think that might be wrong. Could be one of the holes in the chassis that is causing this problem (from that time i had to drill out the motor mount screw) or if the chassis is slightly bent in the middle.

Could also be that HR diff mount, who knows. I'll figure it out.

I have them HR diff mount and their motor mount. Even with a sealed bearing there was a ton of play. I actually shimmed it out. No way it should be tight like that. Something’s up.

 

[-Dusty-]

Its gotta be that hole where I drilled out the screw that I stripped one time. Cuz I did catch a part of the chassis screw hole when I was drilling.

Probably making the motor mount offset or something

 

[olds97_lss]

That blows. I sacrifice the chassis and cut slots in screw heads with a dremel, then use a standard screwdriver to get them out. Then at most, I have a mild slot cut into the pan. I'd only drill them as a last ditch effort, but usually, if it's that far gone, the head twisted off anyway...

 

[-Dusty-]

Hey olds, off topic question. What does your Outcast LV cutoff at?? Been running the outcast today and it seems like the LVC is a lot lower than my kraton

 

[-Dusty-]

So this is the screw hole. Looking from the top and bottom. Looking from the top it looks bad. I didnt think it would have made much of a difference but I guess I was wrong.

I also was looking at the chassis and it has a slight bend in it. Is this normal or no?

 

[joostin420]

No the bend is not normal

 

[-Dusty-]

No the bend is not normal

This makes sense then.. I will try to bend it back, but I will order a new chassis tomorrow. Thanks!

I should also look into getting a tower to tower as well. don't want this happening again

 

[olds97_lss]

Hey olds, off topic question. What does your Outcast LV cutoff at?? Been running the outcast today and it seems like the LVC is a lot lower than my kraton

I haven't really checked. I just plug them into my charger and either fill them back up or set to storage charge. I can take one of those balance testers with me when I go bash next and see where it's at when I hit LVC. I bought 4 or 5 of them just so I could check packs at my house and never threw one in my pit bag.

 

[-Dusty-]

I also remember you posting about your outcast overheating, have you figured that out yet? I got my outcast running mostly on stock and its really running hot. Haven't thermal'd out yet but my outcast was running quite hot yesterday

 

[olds97_lss]

I also remember you posting about your outcast overheating, have you figured that out yet? I got my outcast running mostly on stock and its really running hot. Haven't thermal'd out yet but my outcast was running quite hot yesterday

I think I got it sorted. I replaced my pro-line trencher 3.8's with traxxas 3.8 emaxx tires/wheels which are smaller in diameter and lighter.
Stock tires: 12.5oz
Trencher 3.8: 13.4oz
3.8" emaxx: 11.5oz
3.8" traxxas talons: 9.1oz

The emaxx tires:

Vs proline trenchers:

Trenchers vs backflips:

I never ran the stock backflip tires because I run at a concrete skatepark most of the time and I'm pretty sure it would just grind those down to nothing. So, they are new and untouched on a shelf.

Before the tire swap, I tried gearing down from 16 to 15, then 14, but it still would overheat in the grass when it was 85F outside. Granted, that was after 15 minutes of fairly hard running, but still, I don't want to have to stop and stand there for 20 minutes while the thing cools down enough to run again. When I'm able to get out and bash, I want to bash. Not wrench on cars or wait for things to cool or charge.

Last time I ran, I had the smaller wheels/tires on there. I ran one pack with the 14T. It did fine, but was a bit slow and didn't like doing back flips, not enough wheel speed/rotational mass. Then I replaced the pinion with a 15T and ran 2 sets of packs hard through it with little downtime. One set at the skate park, but a lot of hard pulls in the grass after landings to try to push it, then one set after a 15 minute drive to a dirt pile where I ran it very hard. It didn't overheat on me once and it was 87F outside. For once, I gave in before the truck did. One of the downsides of the traxxas tires are the sidewalls are thin and prone to tearing. They are also horribly balanced. I bought a balancer and a bunch of clay, spent 2 hours spinning/balancing them. They still weren't perfect on the balancer, but seem to spin very well/smooth at WOT.

I was thinking of throwing a 16T pinion on to pick up a bit more wheel speed for easier flips and see how that does.

I bought a set of used kraton tires off the arrma facebook page. They have more tread contacting the ground than the stock tires, but I have no idea how big they are or how much they weigh. Figured I'd try them out anyway, for $40. If they don't work well on this, I have 5 other MT's they will work on. I think they are 1/2" offset whereas the stock/trenchers/emaxx tires are all 0 offset. At least they look like they are 1/2" offset in the photo's. So, that will add more leverage to the arms/knuckles for breakage.

Was also contemplating getting a set of traxxas erevo 2.0 talon ext tires. Guessing they may be a bit heaver than the emaxx tires though. They are a more gnarly talon tread with more rubber. I'm not sure if the sidewalls are any thicker, but they are also 1/2" offset.

 

[Armarookie43]

So this is the screw hole. Looking from the top and bottom. Looking from the top it looks bad. I didnt think it would have made much of a difference but I guess I was wrong.


View attachment 21798
View attachment 21799

I also was looking at the chassis and it has a slight bend in it. Is this normal or no? View attachment 21800

I know it's an old post, but did you ever figure out why your spur gear was all the way forward? I have an issue where my spur gear hex bolts hits the motor mount.