Breaking driveshafts in an awkward location... ideas?

Just broke my second driveshaft in this exact same fashion. Not a result of any sort of big impact, as far as I could see. The wheel just popped off while the truck was going in a straight line. They're nearly brand new shafts, each seeing less than 45 minutes of runtime.

These pictures should do most of the rest of the talking:



Something tells me this may be related:


Any ideas?

seems to be binding prehaps at the wheel area, it seems to be pretty strong though that would be stronger than the torque of the driveline

Yeah. I'm able to turn the wheel with very little effort with my hands. I wonder if it isn't so strong, but the binding happens often enough to produce a sort of recurring strain.

[jayjay283]

what kind of knuckles are those ?

They're the normal white RPM knuckles dyed purple.

[jayjay283]

I dunno man, I use the stock sliders on a vtwin for months and never broke 1, I put a Neu 1515/1y on 6s doing donuts and they didnt break. Maybe your hubs have play ? I used the ofna ones but they didnt work well with HPI or proline wheels, only the axials, so i witched to the new traxxas revo ones LINK no play at all. If those are 23mm you got me, maybe just time for cvds LINK thats my 2 cents lol

[suicideneil]

Someone just had a similar issue on beatyourtruck...

Only thing I could suggest is to try the traxxas cvds, but then they have an issue with the pin snapping in the diff output cups sometimes... meh...

the stock drivelines should not do this...you have an issue somewhere in the wheel area and if you get the CVDs and dont fix the problem I believe the problem will come back it will just take longer

Well I finally got around to a deeper investigation of the breaks. I found this on the bearing on the inside of the knuckle:


The bearing is seized. It looks like there was either some rubbing or something got in there to cause some rubbing. I took the bearing on the outside of the knuckle out of the wheel, and found it's pretty much seized as well. So I've replaced both and put a new end of the driveshaft. We'll see how it works out.

its amazing what a seized bearing will do, I inspect my all my bearing on a regular basis and replace as needed they are not very expensive...anybody remember before they had bearings in RC cars and they had bushings?

[What's_nitro?]

Originally Posted by azjc

its amazing what a seized bearing will do, I inspect my all my bearing on a regular basis and replace as needed they are not very expensive...anybody remember before they had bearings in RC cars and they had bushings?

8 years ago when I got my Rustler it had bushings. That lasted all of 2 weeks. Now-a-days it has a full compliment of Acer ceramic bearings.

Sort of off topic but if you think ceramic bearings are expensive, just know that they are worth every penny. They make regular bearings look like bushings!

[mothman]

Originally Posted by What's_nitro?

8 years ago when I got my Rustler it had bushings. That lasted all of 2 weeks. Now-a-days it has a full compliment of Acer ceramic bearings.

Sort of off topic but if you think ceramic bearings are expensive, just know that they are worth every penny. They make regular bearings look like bushings!

hey, how long you have been using the cer ceramics bearing? Are they really good.. in terms of durability? I'm really interested to get some from acer but not sure if they are good..

[jayjay283]

I use STRC knuckles, they have the larger 6x15 bearing like the RPM but no flex and are very light link
and 2 of these bearings for the inside link , the TRX blue seal bearings fell apart after a month, havent had a problem since

[What's_nitro?]

Originally Posted by mothman

hey, how long you have been using the cer ceramics bearing? Are they really good.. in terms of durability? I'm really interested to get some from acer but not sure if they are good..

Mothman, the Acer bearings carry an ABEC-5 rating (1,3,5,7,9). For all intents and purposes related to RC, you won't find a better bearing. Any ABEC rated bearing at all would be very good. I've had mine for about 6 months doing WOT sprints up and down my street. I haven't noticed any wear at all.

Originally Posted by What's_nitro?

Mothman, the Acer bearings carry an ABEC-5 rating (1,3,5,7,9). For all intents and purposes related to RC, you won't find a better bearing. Any ABEC rated bearing at all would be very good. I've had mine for about 6 months doing WOT sprints up and down my street. I haven't noticed any wear at all.

I dont mean to hijack the thread but Whats Nitro avatar looks just like an album cover that 80s rock band Bullet Boys had