T-Maxx Eating traxxas Steel Shafts

[SchrodeMode]

I am getting this info for a friend and I'm not 100% sure on his set up, but I know the basics. It's an older 3.3 Maxx (short chassis had reverse) that has the wide RPM arms on it, he put the OS .21TM in it and after his stock drive shafts went he threw the steel ones from Traxxas on it (center and outer). He had the problem with the outer drive shafts falling out of the cup, it actually broke the pressed in pin on his first run, fixed that with the extended cups. Now the cups are notching the pins that the cups make contact with, the "T" part, and his center shaft is barely sitting in the cup. If he shims it, it goes too far and locks up. I've told him to adjust his slipper and he told me he did, I've also told him to never land while on the throttle and he said he doesn't. I'm not sure about the slipper but I think most of the damage is because of his jumping skills (or lack of), next time I see him I will try to check the slipper. I'm just wondering if the Traxxas steel shafts are known for being weak, I told him to try pressing a stronger pin in after they break but I think that will eat the cups. He said something about people using HPI dogbones, anyone heard of this before and if so do you know which ones? I am also going to see what his gearing is, I think he needs to up it a little. He just ordered an extended chassis Maxx roller, it will get the .21 and he is going to throw a Dynamite .19 on the short chassis.

Thanks in advance guys.

 

[Snook Man]

Usage will wear both the cup and the cross pin in the bone over time, a little dry graphite on the cup/bone will help slow the wear.
If he’s not using the dust boots, dirt/debris will increase the wear rate, running in sand without the boots the cups/pins will wear even quicker.

As for the rear center shaft not fully in the cup, what diff is he using? The stock 4909 diff input pinion shaft is longer than the extended chassis maxx 4908/7 with the sealed diffs.
Using the rear center shaft with the 4909 diff pinion there should not be a problem.

The HPI 77mm dogbone and extended revo cups work for the rear center shaft on the extended chassis but not on the standard short chassis, the short chassis uses an 70mm dog bone which are hard to find.

 

[SchrodeMode]

Thanks Snook, I know the cross pins will wear eventually but these are new (only about 5 tanks) and are worn pretty good. I think I'm going to have to check his slipper, I guess I'll tell him to look into MIP for replacements on the short chassis and the HPI for the extended.