Axle questions

[meatmonkey]

New to the TF2 and RC4wd, well acquainted with Axial and Vaterra products.

I'm assembling my TF2 and had couple questions regarding the axles.

I normally shim the space between the pinion bearings to help the bearing share side loads from impacts to the driveshaft and such.

I found that a 5x10x4 bearing fits snugly between the bearings, but holds the outer pinion bearing about .2mm from fully seated in the 3rd member. So I figured that I could use a 5x10x3 bearing and approx. .7mm worth of shims. Does anyone see any downsides to adding a 3rd pinion bearing?

I already can't stand the miserable max. steering angle. It seems that the dogbones can "fall" into the slots on the cups and in doing such offer much more steering angle than the rest of the rotation when the outer perimeter of the cup rubs on the inner shaft of the ball. Is it feasible to use a carbide bit to slightly shorten the cups to allow for more angle? I'm concerned that the pin might come out of the opposing slot when at full lock if the cup is shortened. The closed knuckle design makes it hard to tell if this is allowable.

I see that the "upgraded' rc4wd cvds claim more steering angle. But are they actually any stronger?

On my particular axle the front carrier kind of floats around inside the housing like the bearings aren't actually tight in their lands. I don't seem to be having much luck convincing RC4wd that 1.5mm is not acceptable play for such a critical part, and I can't find a housing in stock anywhere. I'm trying not to purchase an entire front axle to get out of my dilemma. Any ideas?

I've found a couple people who've swapped over to XR knuckles and shafts, and while that seems like it might be the best solution it also seems to require more precision machining than I'm capable of.

 

[new2rocks]

Wow...lots to unpack in there. I'll try to help as much as I can, and hopefully others will chime in.

First, regarding adding an extra bearing between the pinion bearings, it strikes me as a lot of effort for questionable benefit on these rigs. You aren't going to need/want to run the kind of power through these rigs that a lot of folks (myself included) run through Axial-based rigs, and the aluminum axle housings are much more rigid than the Axial plastic housings. Those two factors would place the pinion bearings under less stress than you might be used to in an Axial rig. The biggest thing you have to be careful about with the pinions is getting the right pinion/ring mesh. The combination of relatively small ring/pinion gears and shallow teeth make these very sensitive to proper mesh - if it's off by a bit, they will strip. So if you are going to try to add a 3rd bearing between the pinion bearings, make sure you can still get a good ring/pinion mesh.

As far as the steering is concerned, I believe that NorthernBill has had some success improving the steering by shaving the dog bone cups without sacrificing durability. I don't look for the kind of steering in my TF2s that I get out of my Ascender, Wraith or 4WS CR-01. So I've run the XVDs with the stock axles and am quite pleased for my purposes without even having done the shock relocation mod that we discuss in the TF2 guide. And the XVDs have been very durable on a truck with which I've been nowhere near gentle. The Axial steering mod that Winnerone23 and Szczerba have done is certainly impressive, but I don't see it as worth the effort given what I'm trying to get out of my TF2.

As far as the knuckle play is concerned, I'm having a hard time visualizing what you're describing. Perhaps some pix or a video would help?