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Am I just wasting money?

slvrbullet

Well-Known Member
I wanted to get some opinions on a issue I'm having. I have been blowing up rear axles in my golf cart err race utv and I think it is because of the design of the axle. Most all setups the CV joint handles the plunge, on this car the axle plunges. I know this has been tried in the past on sand cars, and the last I remember it being tested in racing was 10 years ago by either Mckenzies or Pro-Am and it failed if I remember correctly. I have included a picture of the latest generation axle and I'm wondering if I'm wasting my time with these and should just spend the $ on the more expensive option that uses dual plunging cv's? dual plunging CV The issues I'm currently having is the axle is pulling out of the cv joints both inner and outer, I have limit straps on a will be going with a shorter strap and I will be replacing the shock shaft bumps stops with either the King or Eibach as the Fox ones are supper soft and fully compress flat. I do have to wonder if the torsional load on the axle is causing the binding and causing the axle to pull apart from the CV?

new axle.jpg
 

michael.gonzalez

Well-Known Member
Sounds like the slip shaft needs a stiffer spring to keep the axle ends being pushed into the CV's. Which brand of axle is this? I know Robby Gordon swears up and down his "triple plunge" cv axles son obviously there must be a right way to do it (and presumably a wrong way also).
 

slvrbullet

Well-Known Member
This is the stock Arctic cat axle, I thought about the spring in the slip shaft but I'm wondering if that would cause issues when the axle compresses and putting stress on the cv's and the splined shaft for the cv cage. Regarding the Robby/Speed axles they look good however if possible I would like to go the stock route if it can be made to work.
 

isdtbower

Well-Known Member
Plunging CV's are made to plunge with the minimum of resistance. Which means minimal effect on the suspension springs and shocks. With too much HP or shock, a slip joint will still want to bind and affect the suspension springs and shocks. I know some shafts were made with balls for splines. They also seemed expensive and never seemed to catch on.
UntitledMA29471081-0008.jpg
 

slvrbullet

Well-Known Member
Plunging CV's are made to plunge with the minimum of resistance. Which means minimal effect on the suspension springs and shocks. With too much HP or shock, a slip joint will still want to bind and affect the suspension springs and shocks. I know some shafts were made with balls for splines. They also seemed expensive and never seemed to catch on. View attachment 205667
I'm pretty sure that's how the Arcticcat ones are made. I will cut the boot on one and take some pictures.

Did you set the axle plunge at full droop?
I have an axle alignment tool that I used and I thought it was dead on I have reached out the the manufacturer of it to verify I'm using it correctly. I limited the droop travel an inch but I'm thinking the amount of preload I have and the spring rate that it is stretching out the straps. Before I was pulling the axle out from the outer CV, after our last test it was the inner that pulled out and twisted the boot. I'm going to put on 2" shorter strap to see if that works. According to the XX FB groups limiting the travel 1' has fixed the issue for a number of people including the guys that race short course. I'm wondering if the long whoops sections and big holes that we are used to in desert racing is just pushing these axles to far?
 

Nessy

Well-Known Member
I'm pretty sure that's how the Arcticcat ones are made. I will cut the boot on one and take some pictures.



I have an axle alignment tool that I used and I thought it was dead on I have reached out the the manufacturer of it to verify I'm using it correctly. I limited the droop travel an inch but I'm thinking the amount of preload I have and the spring rate that it is stretching out the straps. Before I was pulling the axle out from the outer CV, after our last test it was the inner that pulled out and twisted the boot. I'm going to put on 2" shorter strap to see if that works. According to the XX FB groups limiting the travel 1' has fixed the issue for a number of people including the guys that race short course. I'm wondering if the long whoops sections and big holes that we are used to in desert racing is just pushing these axles to far?
The alignment tool is cool but I just jack mine up and see if there is still about a 1/4 inch of axle plunge at full droop. I am not racing mine but after 800 miles of a lot of desert and whoops I haven't had an issue. I have the 18 model and I should probably replace the inner boots. You should try the 3rd gen that they came out with that are supposed to be a ball slide axle like was mentioned above if you dont want to go the Speed UTV route. I would hate to keep taking away travel from my car by strapping the suspension down.
 

slvrbullet

Well-Known Member
So I have the 1/4" of plunge at droop and that is the frustrating part the passenger side has been fine other than just blowing a boot, The drivers side has been the PITA. I think I'm going to try this last generation of axles before giving up on the stock axles.

The only reason why I don't want to go with Speeds/Robby's is because Todd made it known that they will not support racers who make they're own long travel kit for racing only. Todd bluntly said they will not sell the extended Cv's/Axles to people who have not purchased his kit. Now granted I could buy the stock length Speed axles and have extended axles made but what a pain. So unless I'm forced to run his axles I would rather not.

At this point I'm all ears to get these things to work correctly.
 

Nessy

Well-Known Member
So I have the 1/4" of plunge at droop and that is the frustrating part the passenger side has been fine other than just blowing a boot, The drivers side has been the PITA. I think I'm going to try this last generation of axles before giving up on the stock axles.

The only reason why I don't want to go with Speeds/Robby's is because Todd made it known that they will not support racers who make they're own long travel kit for racing only. Todd bluntly said they will not sell the extended Cv's/Axles to people who have not purchased his kit. Now granted I could buy the stock length Speed axles and have extended axles made but what a pain. So unless I'm forced to run his axles I would rather not.

At this point I'm all ears to get these things to work correctly.
Gotcha on the Speed axles but you could always buy them from a Speed dealer. I am with Brad in the next post. Something seems to be going on. Also check your upper shock mounts. They are breaking on people who are racing and using them hard.
 

slvrbullet

Well-Known Member
Follow up on this:

The drivers arm was off about a 1/16". Ran the new Gen 3 AC axles with limit straps with no issues at the last race. I'm going to work with the Textron engineer that built these and see what the max angle these things can run with a decent factor of safety.
 

DGruper

Active Member
Hopefully, you’ve figured it out, but it seems be something you’ve done to modify the car that you haven’t shared. Did you build your own long travel kit or change something from stock? I’m reading through all the posts and the conversation keeps jumping around and you’re concerned that Speed won’t help you because you made some kind of modification. What modification?
The fact that you’re talking about maxed out straps, flattened bump stops, and axles that won’t stay in the car, simply suggests that you are being challenged with how to set up the suspension, or, you’ve made a change to the car. Share what you’ve done and I think you’ll get good advice,
 

slvrbullet

Well-Known Member
The car was going to have long travel suspension but Todd said no on his axles so I held off on that. The suspension minus the shocks is 100% stock, turns out the measurement in the manual was not correct and once that was corrected we have not had axles issues. Literally with the first 2 generations of axle design you had to be withing 1/32-1/16 of an inch or else you would have axle issues. The new generation 3 factory axles have some play so the adjustment of the arms doesn't have to be dead on. The car for the most part is all stock minus the welded in door bars, seat mounts and fuel cell.
 

DGruper

Active Member
Thanks for the reply. Are the shocks a longer travel than stock or did you change the springs on the stock units? I believe you when you mention the tight tolerance of the arms and one would think it shouldn’t be that for an off-road vehicle.
Where in the arm pivot points did you end up making the adjustment? Or you didn’t anything and just let the new axles take care of it?
Interested in hearing about this.
 

slvrbullet

Well-Known Member
Stock shocks, valving and piston are changed, with new springs for the added weight of the fuel cell, spare tire and my fat a$$, I was pretty amazed that a 1/16" would cause the axle to over extend. I made the adjustment to the trailing on the outer heim joint at the pivot point (picture below) I used a measurement I got from a Textron engineer and the axle alignment tool from Speedwerx. From what I do know is the new axle has an additional 1/2" of plunge at full droop to help compensate for arms that are slightly off.
 

Attachments

DGruper

Active Member
Thanks for the picture and description. Sounds like the double plunge axles are the way to go.
 

slvrbullet

Well-Known Member
Thanks for the picture and description. Sounds like the double plunge axles are the way to go.
The new gen 3 axles only plunge at the axle shaft and they are using non plunging cv joints capable of 45 degrees. I have mine apart right now that will be getting Cryoheated I will take some pictures and videos and send them your way. I will show the difference between the Gen 1 and 2 axles.
 

michael.gonzalez

Well-Known Member
The new gen 3 axles only plunge at the axle shaft and they are using non plunging cv joints capable of 45 degrees. I have mine apart right now that will be getting Cryoheated I will take some pictures and videos and send them your way. I will show the difference between the Gen 1 and 2 axles.
Can you post for all to see?
 
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