Front Cvds

[Stets]

Has anyone had any issues with the front Cvds "binding" causing some serious front end wheel "wobble" when turning?
I have tried various types of lubricant, wet, dry, grease and nothing...

I think it has something to do with the pin in the cvd wearing causing slop, which then causes a bit of a lip on the slot of the shaft...
So I upgraded to sr. Irie's cryogenic Cvds and it's still happened...
Are there any other upgrade options? Maybe uni joint upgrades similar to the wraith?

[Sr.Irie]

Mine only start doing the wobble when it is time to service and there full of junk.
Try cleaning all the junk out and re-lube.

There are no other options for the Twin Hammers front CVD's

[Stets]

I've cleaned, filed the burrs, put in new pins, even on your set and still get the binding "wobble".

I'm seriously considering modifying a wraith uni axle and TH swing arms and caster plate

[Stets]

This is about 30% turn.
Brand new bearings, cleaned and silicon spray lubricant (about the smoothest lube you can find), irie Cvds, burs smoothed, I've checked wheel balance, but it happens at very low rpm too.

[XXFETTXX]

I have the same problem, Will dig into it and see what I find.

[Sr.Irie]

If you find anything do let me know what you find.
My axles are still running smooth even after I broke 1pin. I had to repolished it and put a new cross pin in but it is as smooth as ever.

If either of you would like me to try polishing them again or try a new cross pin let me know. I will stand behind my stuff and do what I can.

[iacdmac]

Mine have always done this I am not 100 percent sure, but I believe it started once I added a locker. Can any of you confirm this?

[Stets]

Irie, I don't think it's an issue with your part of the job... It's the third set that this has done it with... They all start out smooth, but end up like this after about 10 hrs of use.

Front locker isn't the cause.

I'm going to try to source a new "cross" but not sure where to get them from

[Sr.Irie]

That is what is puzzling me, I have way more hours than that on mine and like I said still running smooth. I do clean them out and relube with 100% molybdenum disulfide pretty religiously. If I do not clean my hole truck allot the volcanic soil around here will even lock up the A arms and link bars, they literally get stuck and wont move.

If your not in a hurry I can ship you some CVD cross pins the upgrade ones I use. I could put them in a regular envelope.

[Stets]

I don't think this is a problem that is going away in a hurry... So any cross joints pins or otherwise to help figure out, solve, or prevent issues would be very much appreciated.... I've been speaking to a few others and one bloke mentioned "play I the cross joint" I don't have any slop, but it's smooth and loose... And runs smoothly in hand.... It only starts to bind when I put a tyre on.... Any tyre, 1.9, 2.2, I've tried 12 wheels & tyres and it does the same..... Take the wheel off and spin freely ... All good, let it run through my fingers, all good....

[Stets]

I've tried, lithium grease, graphite dry lube, silicone lube, bearing grease, and just for trial even simple wd40..... Cleaned after every run...


I drive it pretty hard sometimes and it takes some tumbles, but I'm not convinced this is due to a bent shaft or anything as it definitely shows in the joint itself

[knightsy]

Hey Stets
This bit from two posts ago caught my eye - "It only starts to bind when I put a tyre on". I know you said you put new bearings in but I wonder of the shaft part of the stub is worn - the stub is sloppy in the bearings/knuckle. And so the mass of the wheel/tyre causes wobble and thus messes with the CVD. Just a thought.

[Stets]

Knightly, that was my first thought.... And wheel balance... The stub axle is quite snug in the bearings, no play at all... And I've tried several wheel/tyres...

[meatmonkey]

Is there any chance what you are noticing is the normal speed velocity variations that all universal type shafts exhibit? Despite their "CVD" name, all these R/C shafts still operate on a geometric principle that is the same as a U-joint (meaning two pivots at *90 to each other). This phenomenon is more noticable with a spooled diffs.

I have perhaps noticed a bit of this wobble you speak of, but I believe mine is mostly noticeable because of the horrific slop in the sliding rack that exacerbates the small amount of "shaking" coming from the "CVD"s when at full throttle and full steering lock simultaneously.

I've broken a couple pins already and, after making new slightly-oversized pins out of drill bits, the joints are still fairly smooth. Just as smooth as any MIP style driveshaft that I've fondled.

[XXFETTXX]

I'm running with the RTR kit as of now.

Stripping it down to put IRIE parts in, and new HD cups from the kit.

Wobble only on the right side now.

[photon_trap]

I think the real issue is a crap design -
other CVDs (they really are not CVDs at all) obviously have no such issues at similar angles. Something in the geometry of the joint causes radical acceleration and deceleration which results in this condition. New or old, it does not matter and lube has little effect, and locker or heavy diff oil exaggerates it but is not the cause.

They are anything but constant velocity joint.

Sr.Irie's reworked joints help but the only way around it is to reduce max steering angle till it is tolerable.

[Stets]

I just saw the new front drives for the yeti... Dogbone one end, uni joint the other....
Exactly what I was thinking to do with a wraith uni joint axle, now if it's the right length shaft, it'll make a good mod

[photon_trap]

Originally Posted by Stets

now if it's the right length shaft, it'll make a good mod

sorry bud, not even close

[Stets]

Originally Posted by photon_trap

sorry bud, not even close

Too long? Too short? If it's too long/short, maybe a cut/weld sleeve?

[fomoco]

Ihave been sitting back reading this binding issue, mine was doing the same thing, about 30percent from full lock left an right, installed brand new cvds new bearings ,then only to find the steel ring that holds the driveshaft cvd pin wasn't even on there an the pin was slowly working its way out an hitting the steering linkage, thus making it wobble when turned left an right, my 2 cents an something to check.