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Automotive Powered Off Road (AKA: Buggys, Jeeps, Trucks, Etc,Etc. ) => Motor and Drivetrain => Topic started by: borris on September 14, 2008, 01:20:04 PM

Title: 930/934 cv's VS u-joint 1/2 shafts
Post by: borris on September 14, 2008, 01:20:04 PM
I prefer cv's over u-joints but a lot of people are using uj shafts now. What's your opinions and pros/cons of each?
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Odyknuck on October 22, 2008, 07:36:13 AM
I dont have any experience on the "U" joints and half shafts however I have heard that they are not as strong as a good race prepped 930 setup. I do know that a halfshaft setup is around $1200.00 versus a 930 setup taht can be had for around $700.00.
You can get more travel with the half shaft setup .
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 22, 2008, 10:12:07 AM
I dont have any experience on the "U" joints and half shafts however I have heard that they are not as strong as a good race prepped 930 setup. I do know that a halfshaft setup is around $1200.00 versus a 930 setup taht can be had for around $700.00.
You can get more travel with the half shaft setup .
I've talked to a lot of people that have run both.I feel that most peeps like the uj's because they don't need to lube them nearly as often and when needed it's a simple matter and much less messy.So the uj's get the nod due to that for a lot of people.
  As for strength I don't know if the uj's or cv's are "stronger" but IMO only they are both up to the task if properly built.There have been many POS uj shafts offered in the last couple of years tho from supposedly reputable suppliers.
   More travel? This is something that I'm not really convinced of.I'll concede a modified uj yoke can accomplish more angular misalignment. Something on the order of 25* cv max  vs 32 or so for the uj. But does that gain as much travel as many think? I'm of the opinion it does not. Why? Due to the the pivot points of the cv and uj being different the cv axle will be longer. That allows nearly the same travel with uj axles @32* as cv axles @25*. These numbers are not accurate but in general are close enough to make my point. Yes, if you run uj's you can run more angle yet but it's not really a good idea. At least not according to uj manufacturers. So to me the only question is which one will transmit torque most efficiently at normal running angles?   .
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: LiveWire on October 22, 2008, 02:10:36 PM
I'll be running CVs capable of 45 degrees at about 32.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 22, 2008, 02:57:43 PM
Non plunging with slip shafts?
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Punkur67 on October 22, 2008, 06:59:33 PM
I know the u joint setup with a plunging shaft has issues with high horsepower and heavy cars. The issue is when the car is under enough acceleration the splines in the shaft can bind up, not allowing the shaft to plunge, which in turn does not allow the suspesion to cycle down till some of the load is removed either by the tire slipping or coming off the ground or coming off the throttle. This was told to me by a big suplier of this product. He said for light cars or cars producing less than 200hp they have had no problems like this but on the big v-8 cars it has been a problem. I only know 1 guy who ran these for a season and after more u joints than you can shake a stick at he went back to 930s. He has also running a mean cast iron sbc. HEAVY!!!
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 22, 2008, 07:39:44 PM
Names?
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Punkur67 on October 22, 2008, 11:18:40 PM
The product was from extreme performance.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: 455bird on October 23, 2008, 01:30:39 AM
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: LiveWire on October 23, 2008, 08:28:58 AM
Non plunging with slip shafts?
Yes. The key when using slip shafts is to not take advantage of the amount of plunge they are capable of. If you have 3" of plunge, then it will take 6 times as much force to slide the splines as if you had 1/2" as well as produce significantly more heat.

Comparing my setup to the one pictured, the male spline is closer to the pivot point on that end. Plus as you pointed out earlier, the pivot points of the CVs are closer to the drive flanges and wheel hubs at their respective ends giving a longer shaft between the pivots. With a longer shaft and most of it being the female end, I have a larger air gap inside the female end. This reduces the pressure increase as it is compressed and therefore side load on the joints. Using a larger, thinner wall tube also increases the air gap.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 23, 2008, 09:11:37 AM
I've heard reports of serious side loads being placed on trans with slip shafts due to friction and air trapped inside and causing bearing failures usually when used with trailing arms. Do you run yours with trailing arms or a arms/5 link?
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 23, 2008, 11:06:02 AM
my drak is basicly semi trailing arms, as it is a 3 link, it plunges pretty good and the trans bearings are holding up just fine...
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 23, 2008, 03:31:52 PM
Big cars not babies.LOL!!!!!
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 23, 2008, 03:45:48 PM
I've heard reports of serious side loads being placed on trans with slip shafts due to friction and air trapped inside and causing bearing failures usually when used with trailing arms. Do you run yours with trailing arms or a arms/5 link?

well you didn't say big cars, and your asking livewire, Who in which builds the car i have, so wanna reprhase?
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 23, 2008, 04:51:23 PM
Hehehe. ;D
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 27, 2008, 07:33:54 PM
Ran across this video again, notice behind the left rear wheel?

http://www.youtube.com/watch?v=Ns6m2NfxNwo&feature=related (http://www.youtube.com/watch?v=Ns6m2NfxNwo&feature=related)
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: plkracer on October 27, 2008, 08:21:29 PM
Nice eye bug! So that is what ruptured the fuel tank!
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 27, 2008, 08:31:22 PM
Nice eye bug! So that is what ruptured the fuel tank!

Dunno, it would be my guess tho, and that sure looks like a Ujoing shaft from the diameter of it...
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Yummi on October 27, 2008, 09:58:47 PM
All day long a quad can "roost" his buddies.  When the time comes - any of them coming over to toss some serious sand?  Nope. 
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: plkracer on October 27, 2008, 10:57:54 PM
Those darned quad guys. They were all in awe watching 80k burn.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: artie on edge on October 28, 2008, 05:02:54 AM
wow..thats a crap happening.

can I ask a question? Tell me to pull my head in cause its off topic...

No fire extinguisher? Also I see vids of rails doin stuff and no helmets?

Is that practise normal over there?

80k worth of machine and no fire ext? Hello???? No nearby machines had one either? Double hello???
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: fabr on October 28, 2008, 06:05:17 AM
wow..thats a crap happening.

can I ask a question? Tell me to pull my head in cause its off topic...

No fire extinguisher? Also I see vids of rails doin stuff and no helmets?

Is that practise normal over there?

80k worth of machine and no fire ext? Hello???? No nearby machines had one either? Double hello???
Unfortunately ,yes.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Carlriddle on October 28, 2008, 06:13:50 AM
I will be buying extinguisher for my "cheap" rail. 

Since its an $80K rail maybe they should get some fire suits like NASCAR.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Yummi on October 28, 2008, 09:15:57 AM
80k is only what they told the insurance adjuster.   :laugh:

I have thought about an extinguisher.  Here is the deal, way back in the day, I used to sell and service them.  Some major brands have a lot of plastic parts.  My $0.02 if you get one, make certain the important parts are all metal (Well, NOT plastic). 

The only brands that I know that were all metal were "Ansul" - they dont make small ones, or "Amerex" - they make nice ones for our application. http://www.amerex-fire.com/main.asp  There might be more, these are just the two I know. 

Stay away from Kiddee for an off road application - home use - just fine.  Lots of plastic etc.  NFG for auto use on or off road. 

Now, in the event you already have a plastic one, and you need it, and it fails to work, chances are the pressure has escaped.  If that occurs,   you can unscrew the top and shake out the powder over the fire like a salt shaker.  BE VERY CAREFUL!  If it still has pressure, it WILL HURT you if you unscrew the top.  The little gauges fail all the time - cant trust them. 

Most important thing is keep your head about you.  Rushing does not put it out - smart thinking does. 

It also helps to insure it so you can just break out the bag of marshmellows and wait for the check.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Carlriddle on October 28, 2008, 09:26:19 AM

It also helps to insure it so you can just break out the bag of marshmellows and wait for the check.

Might be the only to get my money, time, and the cost of all the beer this thing took.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 28, 2008, 05:14:17 PM
To insure my drak for just 10k was 2700.00 pr yr, multiply that by about 8, and its probbaly safe to say that most likely 1/2 the buggys are not  insured...
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Yummi on October 28, 2008, 05:24:11 PM
Serious? 

Mine is less than that.  Shop around.  Should be less than $500.00 per year depending on limits. 

As I run at the dunes, I have high UMBI (Uninsured / Under insured bodily injury limits)  limits so when one of the drunk masses hits me, I have some recourse.   Rub is, you can't have higher UMBI limit than GL limit, so I pay around $70.00 per month for "full coverage" with high limits on the UMBI and a "declared" value of 20k.   If I dropped my GL / UMBI limits to state minimum, I would be less than $50.00 per month.    Then you duke it out with the "primary auto" policy for the UMBI money.     

I am through Foremost.   

I would do some searching - better deals to be had. 
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: SPEC on October 29, 2008, 08:59:22 AM
That was a good post on the fire extingushers Yummie, I keep a crappy plastic one in the buggy but change them out pretty often, I forget the company that makes the in car ones I think bug has a link to them...We used to have to have them in the roundy round cars
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 29, 2008, 03:12:04 PM
yummi, do you have a title, and if so what does it say, I checked with foremost they were one of the most expensive ones..
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: dsrace on October 29, 2008, 10:17:54 PM
There have been many POS uj shafts offered in the last couple of years tho from supposedly reputable suppliers.
   










this is so true master fab. 

to anyone thinking of trying a pair u-joint drive shafts do not use              DRIVE SHAFT SUPERSTORE!!!!!   
 
you would be better off throwing $100 bills in a fire. these guys are getting there parts from china and the 1310 series yokes are cast. I tried 2 pair and had more problems and nightmares in 4 hours than I ever have had.  there yokes actually spread open .02".  In fact I have never had any problems with spicer or rockford products in 8 years.
 jesse at high angle builds quality products as well.
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Yummi on October 30, 2008, 09:56:34 AM
Title: Re: 930/934 cv's VS u-joint 1/2 shafts
Post by: Admin on October 31, 2008, 01:48:15 PM
Getting the title isnt the problem, its the insurance company, they don't wanna insure a assembled vehicle, which is what all of these are until the manufacturer goes threw the right steps to make them a true production vehicle...