I'm really disappointed in the RPM Rear Axle Carriers and front Spindle Blocks

[i_r_beej]

Last night I was cleaning my Boost buggy after running in the dirt over the weekend. I noticed that BOTH camber link ballstuds mounted to the axle carriers were loose. Again.

Attempting to screw them in did nothing... turn, turn, turn. Trying to back them out... turn, turn, turn. So the threads are completely stripped. I have to PUSH the ballstuds out. This is terrible. I've already switched to Hot Racing's front spindle carriers and the shoulder screws have stayed in!

I inserted new ballstuds and secured them with 4-40 nuts. Boom, done. I hope. But what a frustrating experience. Either the material is too soft or the thread bores are a tiny bit too large and don't let the ballstud thread in securely.

 

[WoodiE]

That sucks @i_r_beej and actually very surprising. I've not had any major issues with anything I've bought from RPM so far.

Have you contacted RPM about getting them replaced?

 

[i_r_beej]

Yes, it is surprising. I really like the design of the components and the fact that they allowed the use of larger bearings.

However, from the moment that I installed them, screwing in the ballstuds seemed really easy. Too easy. I was worried about sufficient friction to retain the ballstuds! And within just a few hours of track time they were working themselves visibly loose (1-2mm under the shoulder of the ballstud). The shoulder screws that mount the spindle carriers in the caster blocks also started working themselves loose. And, as evidenced by posts elsewhere on this forum, that wasn't just me experiencing the issue.

I'm not going to bother trying to get RPM to replace them- they've been well used and I'd feel like I was scamming RPM. Really, just securing the ballstud with a 4-40 nut permanently solved the problem and I still get to use the stronger rear axle carriers.

 

[X]

I'm not going to bother trying to get RPM to replace them- they've been well used and I'd feel like I was scamming RPM. Really, just securing the ballstud with a 4-40 nut permanently solved the problem and I still get to use the stronger rear axle carriers.

@WoodiE and @i_r_beej. Unfortunately RPM's warranty policy seems to explicitly state no warranty for stripped threads.



http://www.rpmrcproducts.com/faq/rpm-warranty-policy/

Still, RPM is a great company. I wouldn't be terribly surprised if they helped you out anyway.

 

[WoodiE]

Well you learn something new everyday. I personally can't say I've ever had a problem with stripped threads using RPM products, but I never knew they had this in their policy. Makes sense though.

 

[i_r_beej]

The stripped holes was a bit of a surprise since I'm always very careful about threading screws into plastic. As I mentioned earlier, upon initial installation the ECX ballstuds threaded in with very little resistance leading me to believe that the bore holes were slightly too large a diameter. And very likely the reason why the ballstuds would work their way out. I contacted RPM about this and their reply was to use CA as a threadlocker.

I think that when I tried to remove the ballstuds, the glued screw shaft destroyed the shallow threads cut into the plastic and effectively reamed out the bore hole. (The ballstuds working themselves loose probably caused plenty of damage too.)

I honestly have no interest in contacting RPM about this. The original fitment of the ballstuds was suspect and I should have just secured them with a 4-40 nut in the first place.

I'm still running the rear axle carriers and all is good for now.

 

[skipper]

I have a similar problem with RPM steering knuckles on my Ruckus. They're actually the Blitz ones as I've converted to Blitz camber blocks & knuckles, but are obviously the same material. Basically, the little cap head screws keep backing out, as you can never seem to get them tight without locking up the whole knuckle. The softer / stronger plastic, combined with the tiny threads of the M3 cap head screws, mean they're forever coming loose... Will be ordering some ali STRC bits for the Ruckus so I can use a drop of locktite, and to will make use of the RPM bits on my son's Torment, after moding them with some 1/8 scale flange tubes & cap head screws, which should be more up to the job.