Premium members don't see ads. Clickhereto upgrade.

centre CVD mod

Biddie_fiddler

Well-Known Member
Messages
246
Location
Perth, WA
Been looking into potentially removing the centre driveshafts and replacing them with CVD, found one thread talking about a similar mod (see link). Nothing really came of it so I want to start a more formal and proper thread for this topic.

So to cut a long post short, I am going to be replacing the centre shafts and cups with a CVD drive. For reference, these are what are used in the standard setup:
HPI 109907 - 8x70.5mm drive shaft
HPI 86054 - 8x142mm drive shaft

I need help!

I have found one CVD that will work for the smaller dogbone:
70-80mm CVD with a 6mm internal diameter.
1574821588738.png

I am yet to find one that will fit the XL driveshaft though. If anyone can help out its greatly appreciated!

This is all a means to test it out and see if its worth it! I will keep this thread updated with any updates and research! 🙂
 

olds97_lss

Well-Known Member
Messages
2,258
Location
Dekalb, IL 60115
I ran the hot bodies center cvd on my X for a while, but kept snapping the pin inside the cvd joint. After replacing the 3rd or 4th pin, I went back to a dog bone. I think HPI had a cvd as well, which I also ran.

I used to run the cvd back when I ran an OS21RG in my savage 21 with stock or traxxas 3.2" wheels/tires, which was a relatively low powered engine. I started snapping the cvd pins when I started running the LRP 28 in it. I've snapped a bone as well with the LRP30 in it. That's with the X, which is shorter than the XL.
 

Biddie_fiddler

Well-Known Member
Messages
246
Location
Perth, WA
I ran the hot bodies center cvd on my X for a while, but kept snapping the pin inside the cvd joint. After replacing the 3rd or 4th pin, I went back to a dog bone. I think HPI had a cvd as well, which I also ran.

I used to run the cvd back when I ran an OS21RG in my savage 21 with stock or traxxas 3.2" wheels/tires, which was a relatively low powered engine. I started snapping the cvd pins when I started running the LRP 28 in it. I've snapped a bone as well with the LRP30 in it. That's with the X, which is shorter than the XL.
I assumed the weakpoint would move to the pins in CVD's like you've said.
The ball cups that hold the driveshafts in place on my rig are sloppy, they are quite old and have taken some pretty good abuse, figured I'd give these a try instead of replacing them.

The way I see it, the CVD's will remove the "slop" in the driveshafts. By the photos the pins do look quite small, but I have a centre diff in my rig so I'm hoping that helps with the stress that'll be put on the CVD's.

They're designed more for crawlers, with high torque and slow speeds. With these the torque isn't instantly applied as a shock load, but with the way you drive MT's they're gonna get some pretty hectic shock loads applied.

Either way, thought I'd give it a bash and see how it goes then report back. Call it an experiment 😂😉
 

Biddie_fiddler

Well-Known Member
Messages
246
Location
Perth, WA
Update

Ordered the CVDs that will suit the rig. The link I had in my previous post seem to be the only ones I can find that do the sizes I need with a 6mm inner diameter.

If anyone is curious, it cost me $39.82AUD delivered, I got the 70-80mm and the 110-155mm.
They will be here in about 2 weeks which is perfect seeing as I'm away in Sydney for a holiday. When I get back they should hopefully be here. Same goes for the 5mm shaft ali shocks... I managed to bend a shaft on them thicc boys!
 

BrandNewSavvy

Member
Messages
27
Call Eustace at MIP if you are having trouble with the fit. My question, however, why not run universals or stick with the dog bones
I've run all three and prefer universals over CVAs.. they have less bind (especially at the drive shaft angle), in addition to CVAs binding while under acceleration--which is the exact opposite for universals. I know you can combat the binding with joint grease but you better check after each run or the CVAs become a liability. Even kept clean (very hard to do, even with boots) , they wear much faster than the other two alternatives. Just curious what is making you want to run CVAs? From an actual performance stand-point you won't be able to tell a difference. Plus you have potential issues with the fit, etc. etc. I already had them on hand which is why I tried them out but I'd hate for you to just throw away money on something that's not going to make a difference, and possibly take the truck a step backward. Let's hope they workout for ya however, let us know how you do!
 

savagenitro

Member
Messages
5
i tried all sorts back in the day, and still think the doggone is the best setup for these trucks, but if it works out good, let us know!
 

Biddie_fiddler

Well-Known Member
Messages
246
Location
Perth, WA
I think I mentioned it in the beginning, I wanted to do it just to try it out and experiment with it 😜

I wasn't planning on getting any performance benefit from it, just wanted to see if it was possible to install CVDs and see how they perform. They might break first go but thats all part of the fun.
 

zhensofa

New Member
Messages
1
Call Eustace at MIP if you are having trouble with the fit. My question, however, why not run universals or stick with the dog bones
I've run all three and prefer universals over CVAs.. they have less bind (especially at the drive shaft angle), in addition to CVAs binding while under acceleration--which is the exact opposite for universals. I know you can combat the binding with joint grease but you better check after each run or the CVAs become a liability. Even kept clean (very hard to do, even with boots) , they wear much faster than the other two alternatives. Just curious what is making you want to run CVAs? From an actual performance stand-point you won't be able to tell a difference. Plus you have potential issues with the fit, etc. etc. I already had them on hand which is why I tried them out but I'd hate for you to just throw away money on something that's not going to make a difference, and possibly take the truck a step backward. Let's hope they workout for ya however, let us know how you do!
Do you have pictures of your universal and CVA? BTW, I am a little confused about the term "CVA" vs "CVD". Are they the same thing?

Thanks
 
Top