Broke my CVD..

[FinCrawler]

Originally Posted by Jeepiac

I don't know how you're getting the same steering with dog bones as you are cv's? After reworking my knuckles and c-hubs the dog bones would catch on the cups and bind. I'm even running R1 gears in the front Of my Sawback and not a problem one. Why 3s in a Sawback? You run some type of G6 style speed events?

Well i have dremeled the knuckles and c-hubs also and i dont have any problems getting the maximum steering with dog bones.

You know, Sawback with the stock 12t pinion is far from fast attack vehicle with 3S lipos. Actually, i was on a safari comp yesterday and needed a winch help at some trail ports because i was lacking wheelspeed and with decent wheelspeed, ive could run those spots without problems.
Im just considering 27T motor and at least 16t pinion to get some more speed.
The fact that the speed is there doesnt mean that im using it all the time, just good to have a bit in the reserves when needed.

BTW, just curious, how R1 gears differ from Sawback gears?

[Jeepiac]

They both have the same number of teeth on the diff gear, but R1 pinion is 3 teeth bigger. With some grinding on the end of the diff gear and clearancing of the inside of the diff housing to make room for the bigger pinion it'll work. Not a big change in gearing, but every little bit helps. If you know your rig, as I'm sure you do, you'll notice a tighter turning radius. I have noticed any improvement in climbing ability or anything else, just better steering.

[FinCrawler]

Originally Posted by Jeepiac

They both have the same number of teeth on the diff gear, but R1 pinion is 3 teeth bigger. With some grinding on the end of the diff gear and clearancing of the inside of the diff housing to make room for the bigger pinion it'll work. Not a big change in gearing, but every little bit helps. If you know your rig, as I'm sure you do, you'll notice a tighter turning radius. I have noticed any improvement in climbing ability or anything else, just better steering.

Ah, the old gearing trick. Didnt know R1 gears has more teeth.
I think i have to try that also..

[Jeepiac]

It's worth the time, and it's really not hard to do. Don't know why I never hear of anyone else doing it.

[FinCrawler]

Funny, i sent email to Junfac about the quality of those CVD's and they answered that they have sold a lot of those and only 5 reclamations so far.
If thats true, my reclamations cover two of those five, so i find it quite hard to believe..
Oh well, still not going to buy those no more.

Sent from Sony Xperia Z1 Compact

[FinCrawler]

Was on a safari comp again last weekend and one fellow competitor had Sawback with CVA's installed.
No surprise when he was one of the first with dnf as his axles broke.

Now, IF anyone has broken cva axles and they break, please make a reclamation to Junfac as its the only way to get Junfac to do something about this issue.


Sent from Sony Xperia Z1 Compact

[chopfather]

I have a couple runs on mine and so far they are holding up. I'll definitely post here if they do break though.

[Jeepiac]

I have beat the living SHIT out of mine and no problems yet. I'm wondering if some people are modifying the steering to far and it's causing the joints to bind? I'm taking the Sawback to Crawlapalooza this coming weekend and I'm thinking this should be a good test (like I haven't tested it already) If anything fails I'll let y'all know.

[PSH72]

Iven if they were " modifying the steering to far and it's causing the joints to bind? " wouldn't they brake the stock ones too?

Fincrawler says he went with the dogbones and had no issues, if it was modifying the steering it would brake the dogbones, but since they still are holding up, that leds me to think that there is a problem with the CVA's

[Jeepiac]

Originally Posted by PSH72

Iven if they were " modifying the steering to far and it's causing the joints to bind? " wouldn't they brake the stock ones too?

Fincrawler says he went with the dogbones and had no issues, if it was modifying the steering it would brake the dogbones, but since they still are holding up, that leds me to think that there is a problem with the CVA's

Good point. I wonder if there are different variances of these shafts and maybe I got lucky and ended up with a good set. Mine have been going for 9 month in a 7 pound sawback. So far so good.

[FinCrawler]

Originally Posted by PSH72

Iven if they were " modifying the steering to far and it's causing the joints to bind? " wouldn't they brake the stock ones too?

Fincrawler says he went with the dogbones and had no issues, if it was modifying the steering it would brake the dogbones, but since they still are holding up, that leds me to think that there is a problem with the CVA's

Exactly. And in this recent case, the axles snapped when he was driving straight and both axles snapped simultaneously after a little bump.

So far no probs with dog bones, not even when i have dremeled the knuckles and hubs.

Too bad that there most likely will not be any other manufacturer CVDs coming to market..

[Jeepiac]

I'm starting get scared to run my Sawback, and my main crawler has R1 axles with Junfac cv's and they look kind of weak. Thinking I may change my driving style lol

[chopfather]

I just added some weight to my wheels and tires and plan to build some bumpers and a cage. Maybe the added weight will result in some carnage !

[Jeepiac]

I really think there must be a power difference between the rigs that might quicken the failure rate. Mine is at 7 lbs and I run heavily weighted high mass aluminum wheels, but I run a 35T can motor and 2s Lipo. After a day of crawling I clean and grease all the CV's on my crawlers. Maybe since I run on the lower end of the power scale and keep everything lubed is why I'm having good luck so far? Not sure, but I'm going to keep doing everything I've been doing and maybe start saying a little prayer before each crawl

[Natedog]

Originally Posted by Jeepiac

Good point. I wonder if there are different variances of these shafts and maybe I got lucky and ended up with a good set. Mine have been going for 9 month in a 7 pound sawback. So far so good.

Good luck, have fun and let us know how it went!

Originally Posted by Jeepiac

I really think there must be a power difference between the rigs that might quicken the failure rate. Mine is at 7 lbs and I run heavily weighted high mass aluminum wheels, but I run a 35T can motor and 2s Lipo. After a day of crawling I clean and grease all the CV's on my crawlers. Maybe since I run on the lower end of the power scale and keep everything lubed is why I'm having good luck so far? Not sure, but I'm going to keep doing everything I've been doing and maybe start saying a little prayer before each crawl

I think this is the main difference, the other guys are running 3s (one with sensored brushless, the other with brushed) but this is significantly more torque than your 2s and 35T brushed motor.

[scaled]

Broke a CVA today and I was just trail driving, no big drama. Second run 35T, 2s.

[nbr4]

Originally Posted by FinCrawler

After a year i would like to know if im the only one who broke those CVD´s or is the quality just plain poor?

A year late I know. Wish I would have read this long ago. I have bought two cvd packs from junfac the first I bought cause the dog bone ends broke off. Tumbled with the first cvd and broke got the second pack and a few weeks ago approaching a rock with the front tire the second set broke. I run a 17.5t 2 pole brushless motor with a 2s battery. Very lame. What do I get now?

[malickie]

The CVD's seem to suck from Junfac, even the ones from GPM I managed to break. Starting to think I either need to swap over to an entirely different axle or go back to dog bones, as they seem to have better build quality. I think the inherent problem with the CVD's is that they are using a little pin to go through the hole and the hole is not nearly thick enough on either end to deal with what it is supposed to handle, let alone the small pin size and than the stupid ring that goes around it.