drive line chatter

[steveo 561]

has anyone experienced drive line chatter seems to happen at low speed, this was my first power up on my wroncho i have flipped the tranny and my axle diffs are on the opposite side so the drive shafts are at an angle with new rc 4wd cvds. i would not say that the cvd is at its limit but pretty close

does this happen with extreme drive line angles i have seen, i did not have this with stock axles with more straight line drive shafts

the drive shafts are new and i could feel some resistance when cvd was angled like some times they do

i started looking into flip flopping the front for the rear axle i know i could not do this before i got bent upper links, should i try

 

[Jus]

It's certainly possible it's the cvds being at large angles. Are they lubed at all? Are the pins lined up from trans output to axle? That can cause some issues also.

 

[Rook82]

It is most probably binding in the driveshaft joints. It is most noticeable in an rc at low speeds as the motor isn't generating enough power yet to ver come the binding. Once at a higher speed the motor may just power through it and you will not see or notice it. It is hard to explain. But when a joint is angled at all (the more angle the more the effect), you get a variance in speed as the joint spins. Having the angles of both joints on the drive shaft the same will help cancel this out. But in the case with the rc and such a small scale it is hard to do this. Often times the axle side output is angled up to help the driveshaft not hit the rocks, etc. But when you do this you change the joint angle. Looking at it from the side, front to rear the driveshaft is often strait in line with the output of the axle. But at the transfer case it is angled down. You have two very different angles. You will get vibrations or chatter (in your case). This article helps explain it.

Operation of U-Joints

As far as what all that means to rc? Well try and keep the angles to a minimum. In a full size vehicle you would get horrible vibrations at higher speeds. But that doesn't mean much for an rc. If you have too much of an angle on the rc's, you can just deal with it and run it. You may be ok. What may happen is the shafts and or the shaft joints "may" fail from wear. Some shafts can handle more of an angle then others. But your best bet for performance and reliability is to get the shafts and their joints to as small of an angle as possible.

 

[steveo 561]

thanks for the info and i know the less angle is better the axle is angled up its just the side ways angle is killing me, i figured it to be the culprit and i have seen some extrme angles on some drive shafts on a few crawlers but never read about the chatter affect which its got to have at that angle

thanks its not really a crawler anyway i think i can live with it for now or flip the tranny back and see if my upper will clear now they are bent links

 

[steveo 561]

i found the problem as i remember now one of the shafts had a tight cvd so i took it apart did a little sanding and problem solved, i think its a month or so since i put them on

 

[Rook82]

i found the problem as i remember now one of the shafts had a tight cvd so i took it apart did a little sanding and problem solved, i think its a month or so since i put them on

Ya that could contribute to it. Just like in a 1:1, the joints need lube. After runs or at least after runs with water and mud, I clean my rigs pretty well. I get rid of the dirt/mud then lube everything. I use a thing oil on the bearings that seep in pretty good. Mostly I use "Rem oil" for guns on the bearings. It is cheap and I always have it for my firearms. But for things like the shafts, I use a thicker oil or a grease. I usually just rape my gun cabinet for something. That is where I get most of my lubricants. I use regular marine grease that comes in tubs at the auto or boat store for the diffs or internal transmission gears, etc. I like the marine type greases as it seams they use additives to help it not wash away with water. not sure if that is it or not. But I have never gotten fancy with lubes or greases, just around the house stuff and have had great luck so far. I do keep things well maintained. I think that is more important then using the beast lubes. in other words, frequent changes and maintenance with basic lubes beats just using top end stuff then never touching it.

Having a tight or dry joint may be pushing the operating angles over the edge and some cleaning lubing may work for you.

I know what you are saying with the high side to side angles with the Wroncho. That is why I flipped the trans and dealt with making bent links work. Having good shaft angles was more important to me. Plus my rear shaft was a little short :roll: set up like that. If you can, take the time to do the bent link to clear the drive shaft mod. Great once you work it out. "thumbsup"

 

[steveo 561]

well i just bought the bent links will they clear i dont know, but i did see rc4wd has a center diff axles housing for the wraith which would more to scale i pondered it for a minute but for $100 nah, i to would like a more straight approach with this thing being more of a high rpm mud slinger but i think i will be ok for now. thanks for your input

 

[tamiyatim]

Hey Guys, curious... what is the bent shaft mod? does that do something to straighten out the driveshafts? Anybody got a link?
Thanks!