CV Axle Shudder

[drewp29]

So it doesn't shudder when in 4wd with the hubs unlocked, or at least it doesn't shudder enough to differentiate between the shudder and the road bumps. When I am in 4wd with the hubs locked it feels like the passenger tire is flopping around on the spindle. It's that bad. But only when I get the rpms up. If I drive it easy it is still there in 4wd but it doesn't feel like the wheel is going to come off at any moment.

 

I am about 90% sure it is the CV axle. It is very easily identified as the passenger tire that is experiencing the vibration. I have another axle on it's way (thanks Marty @ Raxles), so hopefully I put that one in and everything is golden.

[XPLORx4]

When you replaced the axles, did you remove the brass washer/spacers on the old CVs and move it to the new ones? The spacer I'm referring to slides onto the outer CV axle before you insert it into the hub. It's about 3/16" thick and beveled on one side.

Edited March 12, 2013 by XPLORx4

[drewp29]

Yeah, I made sure the thrust washer was there. Initially I thought I might have left it on the old CV, but I checked the old CV and the new one when I re-installed it.

[projekz]

I'm having the same issue. I think Adamzan might be right. I'll take my front driveshaft out and drive it around to see if it fixes my issue.

[drewp29]

I'm having the same issue. I think Adamzan might be right. I'll take my front driveshaft out and drive it around to see if it fixes my issue.

 

Let me know what you figure out. I am going to replace the passenger's CV axle hopefully Friday night, and if that doesn't solve it, then I guess it is time to look at u-joints. I had initially planned on replacing all of them at some point, and I guess while I am at it I might as well take care of them anyway.

Edited March 13, 2013 by drewp29

[drewp29]

I am at a loss . . . replaced the CV and the rattle is still there. Pulled the front drive shaft and the rattle is still there. My only other thought is maybe the Mile Marker hub failed and it isn't engaging properly?

 

I am going to put the drive flange back on that side and see if it goes away. Otherwise I have no freaking clue . . .

 

Edit: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGGGGGGGGHHHHHHHHHHHH

Edited March 17, 2013 by drewp29

[Rick13]

May not be any help here what-so-ever, and I realize you said it was only at a specific RPM (not vehicle speed or amount of throttle) but these are my first thoughts for a shudder-like feeling while driving...

Tires/wheels in good balance?

Are your wheel bearings in good shape or had the outers repacked recently? (Or maybe you can at least make sure they are properly seated)

New ball joints look OK? And are all front suspension and steering components properly secured/torqued?

Motor mounts in good shape?

Edited March 18, 2013 by Rick13

[drewp29]

So it isn't the manual hub. What are the odds that the SLIGHT difference between the driver and passenger side geometry is enough to cause the CV to have issues?

 

Here is what I have found:

 

When I am under the vehicle and I manually turn the CV axle on the passenger side there is a point in the rotation that is like a hump you have to get through before it is smooth again. When you go over the hump it wants to push the front differential towards the driver side. You can actually see the front diff move when this happens.

 

The vibration gets worse as the passenger wheel is unloaded while driving, and better when there is a passenger in the car and their weight is compressing the suspension.

 

Anyone have any guesses as to what is going on here?

[drewp29]

May not be any help here what-so-ever, and I realize you said it was only at a specific RPM (not vehicle speed or amount of throttle) but these are my first thoughts for a shudder-like feeling while driving...

 

Tires/wheels in good balance?

 

Are your wheel bearings in good shape or had the outers repacked recently? (Or maybe you can at least make sure they are properly seated)

 

New ball joints look OK? And are all front suspension and steering components properly secured/torqued?

 

Motor mounts in good shape?

 

 

Motor mounts look fine, and there aren't any bangs or thumps when loading the drivetrain and watching the engine shift when you gun it.

 

Wheel bearing on passenger side I repacked during this whole process, the bearings were smooth and the races didn't have any scoring. There was no play in the wheel when I checked to see if the bearings were tight. I torqued the bearing to 65 ft-lbs, backed it off and lightly tightened it before putting on the lock ring and screws, so I believe it is seated correctly.

 

I checked all the suspension bolts, etc. and everything is tight.

 

I swapped the two front wheels to eliminate tire balance/wheels, the vibration is still in the passenger side.

[projekz]

I am at a loss . . . replaced the CV and the rattle is still there. Pulled the front drive shaft and the rattle is still there. My only other thought is maybe the Mile Marker hub failed and it isn't engaging properly?

 

I am going to put the drive flange back on that side and see if it goes away. Otherwise I have no freaking clue . . .

 

Edit: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGGGGGGGGHHHHHHHHHHHH

Are you running OEM CVs? I've had a few bad aftermarket CVs from Napa. I'm going to rebuild the OEM CVs with Rockford boots and hope it gets better.

[Rick13]

So it isn't the manual hub. What are the odds that the SLIGHT difference between the driver and passenger side geometry is enough to cause the CV to have issues?

 

Here is what I have found:

 

When I am under the vehicle and I manually turn the CV axle on the passenger side there is a point in the rotation that is like a hump you have to get through before it is smooth again. When you go over the hump it wants to push the front differential towards the driver side. You can actually see the front diff move when this happens.

 

The vibration gets worse as the passenger wheel is unloaded while driving, and better when there is a passenger in the car and their weight is compressing the suspension.

 

Anyone have any guesses as to what is going on here?

 

Can you pull the NX4 strut spacer? If the problem is with the angles/geometry of the new axles, this might lessen the effect and narrow the search.

[drewp29]

Can you pull the NX4 strut spacer? If the problem is with the angles/geometry of the new axles, this might lessen the effect and narrow the search.

 

Yeah, that's my last resort . . . I don't want to cause I like the way it looks right now, but I may be forced to if nothing pans out. I am going to put one of my old CVs back in and see if the problem persists. If that solves it then I don't know what to do other than pull the NX4 spacer.

 

If it isn't the CV then I will look at the outboard front differential bearing. And if it isn't that then the last thing it could be is the differential, which doesn't make all that much sense given the symptoms. The bearing I suppose could be the problem . . . but it's still guess and check theory.

 

 

 

Are you running OEM CVs? I've had a few bad aftermarket CVs from Napa. I'm going to rebuild the OEM CVs with Rockford boots and hope it gets better.

 

They are Raxles which have a great reputation. I can't believe given their rep that I would get 2 in a row that are bad, but I suppose you never know.

Edited March 18, 2013 by drewp29

[Rebelord]

So it isn't the manual hub. What are the odds that the SLIGHT difference between the driver and passenger side geometry is enough to cause the CV to have issues?

 

Here is what I have found:

 

When I am under the vehicle and I manually turn the CV axle on the passenger side there is a point in the rotation that is like a hump you have to get through before it is smooth again. When you go over the hump it wants to push the front differential towards the driver side. You can actually see the front diff move when this happens.

That sounds like a binding issue. Which at speed will be pronounced. If the CV axle doing that is aftermarket one. But you have a stock one. I would put in the stock one and see if it does the same. If it doesnt, and you take a drive and no vibration is there. Then that is your issue.

You posting that makes me believe its that.

Otherwise, I was going to say the same as other, check your bearings. But if there good, they are good.

[drewp29]

That sounds like a binding issue. Which at speed will be pronounced. If the CV axle doing that is aftermarket one. But you have a stock one. I would put in the stock one and see if it does the same. If it doesnt, and you take a drive and no vibration is there. Then that is your issue.

You posting that makes me believe its that.

Otherwise, I was going to say the same as other, check your bearings. But if there good, they are good.

 

I have never really encountered a CV binding issue on other vehicles, only the telltale clicking during cornering so I don't have a point of reference. It makes me wonder though if it is binding, why only in one spot around the circumference? If this is a typical tripod joint would binding not occur at three points? The roller bearings would be in the same orientation at (3) different points over 360 degrees right? This is why it seems odd to me.

 

Unless there is one bad bearing and it is causing the issue. It's all just postulation unless I could see the joint throughout the rotation.

Edited March 18, 2013 by drewp29

[ascdesigns]

Possible suggestion to try before entirely swapping the stock units back in: while the front end is on jackstands, disassemble the NAPA units, but rebolt the CV to the diff, leaving the splined end out of the hub - probably 3 bolts is all you need. Rotate the CV by hand to see if the binding still exists. This way, you can manually adjust the CV angle and determine if it's the CV itself at a certain angle.

 

The unhappy possibility: my '98 Pathy had *exactly* the same symptoms your is exhibiting. I did the above test and found zero binding in the CV but when rotating the diff by hand there was a seizure somehere inside the pumpkin. This was causing the "hump" you refer to in a previous post. I *think* it was from one of my Warn hubs accidentally disengaging causing various non-intended gear/bearing rotations inside the diff. I certainly hope this is where your problems differ from mine. Now, on my new (old) '97 Pathy, I'm now paranoid and frequently checking that my hubs are either both locked or unlocked.

 

Best of luck! I look forward to hearing how you resolve this - hopefully it is only a defective CV!

 

- Al

Edited March 19, 2013 by ascdesigns

[drewp29]

Best of luck! I look forward to hearing how you resolve this - hopefully it is only a defective CV!

 

- Al

 

 

Actually at this point in time I am hoping it is something other than the CV - Raxles have a stellar reputation and the possibility that I received (2) bad CVs in a row from them is slim. If it is the CV binding then it most likely means something is amiss in the suspension geometry. Given that the angles on both the driver and passenger side appear to be about 20 degrees (you can't really get a magnetic protractor on the axle with the freakin control arm, strut, and sway bar cramming everything up) it has to be a weird anomaly that I believe will not be able to be corrected. I might be able to correct it for now by removing the NX4 spacer, but in all likelihood I'll still have the issue when the tire is unloaded during cornering and wheeling.

 

If it is differential or bearing related I can deal with that, and replace the applicable parts. It just means my refresher of all things drive train related will happen sooner rather than later. If I have to replace gearing I might look into replacing the rear gearing at the same time to account for the larger tires. I have to go through the H233b rear diff eventually due to the excess amount of metal that came out when I drained it and replaced the fluid. It will have to be done at some point.

 

Anyway, what exactly was wrong with your differential?

Edited March 19, 2013 by drewp29

[ascdesigns]

Hey Drew,

 

Honestly, I never took it much beyond diagnosing something was wrong inside the front diff. There was a domino-effect that impacted (literally) my transfer case as a result of whatever was seizing in the diff to the point I couldn't engage 4hi anymore.

 

Since I had paid <$1600 for the '98 and it had the rusted strut towers along with massive trans shifting flares, I wound up scrapping it. But I liked the Pathy so much I bought a '97 a few months later. Sorry, not much help for ya with the problem.

 

- Al

[drewp29]

Al,

 

No worries! I have enough into mine that I will fix the issue no matter what, so hopefully it isn't anything major. I have shifted into 4hi recently and it didn't seem to have any issues, so the transfer case should be fine.

 

Thanks for the tips though!

[drewp29]

So I think I can safely say that it is indeed the angle of the cv on that side. I put the stock cv back in the vehicle and the vibration is still there, but it is much less pronounced. Also, with the wheel at full droop there are 3 spots where the axle binds. When the vehicle weight is on the suspension there is only one spot.

 

So, here is my plan. I don't want to lose the added height of the NX4 spacer, but I absolutely need to pull it. So, I am going to take some 1" thk. plate and drop the front subframe, and pull the NX4 spacer as well. That way, I drop the differential 1" as well as raise the outboard CV 1", which should negate 1" of gain (at least in the CV angle) from the AC coils and leave the truck level front to back.

 

Solving the issue this way will also allow the stock brake lines to remain in place. The only thing I will have to do over the subframe/engine blocks is space out the steering rack.

 

What do you guys think?

Edited March 20, 2013 by drewp29

[Rick13]

Well, at first, I was like, "Welcome" (to the SFD world).

 

But then, I was thinking...you should NOT be having that type of problem with only a few inches of additional height/change in angles. If it were me, I might actually try a Advance Auto/Orielly CV just to see if the raxles (sp?) have something that's just plain unique to them. But don't do it just because I said that, I'm quite unique in my approach to stuff.

[drewp29]

I was considering biting the bullet and doing a full on SFD, but since the AC coils are brand spanking new I would like to run the rears a little while before I get the itch to go big. I guess I could build a spring perch for them, but welding the perch on might make it difficult to go with longer springs/dampers later.

 

The reason I put the stock CV back was to determine whether it was the Raxles CV or something else in the drive train. Since the stock CV has the same issue just less pronounced it very well could be that the Raxles CV is unique and cannot handle the angle increase.

 

However, since the stock CV does have the same issue, I feel that there is something different about the suspension geometry on that side. That is why I think adding a 1" sub frame spacer will solve the issue entirely.

[drewp29]

My plan might be incorrect.

 

The distance from the strut mounting point (engine bay) to the center of the hub needs to remain the same in order for the body to remain the same height. So in order to lower the inboard CV to where I intend I need to block the sub frame 2", correct?

 

That way I can leave the NX4 spacer and the body will remain level where it is.

 

The crappy thing about that is I effectively lose 1" of ground clearance from where I am now.

[mel.d]

I just installed two new CV axles today and had the same issue with binding on the passenger side. I ended up having to adjust my camber kit so that I have 1 degree of positive camber to resolve the binding issue.

 

I think the new axles have tight tolerances and the lift is causing too much angle for the axles to handle. I'm hoping after a few thousand miles, they should break-in enough for me to adjust the camber back.