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Replaced Front CV Axles - now there's vibration?


ascdesigns
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Hi - Looking for suggestions here. Search didn't turn up anything, or maybe I didn't search correctly - sorry if that's the case.

 

I just replaced both of my front CV axles. The originals' boots were both torn on the outside joints. It was an easy job, thanks to the write ups on this forum. The problem is that now when I engage 4-HI, there's a vibration at 35mph and at 55mph. Not shaking like the truck is going to explode, but definitely noticeable. If I disengage the 4-HI and go back to 2-HI, the vibrations cease and all seems normal.

 

Did I miss a marking of some sort on the flange mount to the front differential that's causing these vibes? The OEM axles never behaved this way. I know driveshafts are typically balanced and marked, but I didn't think the CV axles were. The CV axles are remanufactured units from NAPA.

 

Here's some basic specs on my R50 in case they have any bearing on the vibrations:

-OME HD springs up front, OEM regular springs in rear. So basically it has a 1.5" lift (I think?) so nothing to drastic for the CV axles.

-Warn Manual Hubs - yes, the cir-clip is correctly mounted in the groove on the splined axle.

-CV flange bolts were torqued according to spec in the FSM.

-Lower control arm bushings and bolts are in good shape and properly torqued (respectively).

-Wheels are balanced (it's only when in 4-HI that the vibes are there).

 

Any suggestions what I should do with these axles, assuming it's the cause? Rotate each of them on the flange side? Is it possibly because the transfer-case-to-front-diff driveshaft may be a bit more worn and the CV axles are new and tight? Ignore it and just drive :happy:;-) ?

 

Thanks in advance,

 

Al

Edited by ascdesigns
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I am having the same sort of vibration problem in 4wd, although i didnt recently replace my CV's, It just started happening a week ago and its only under acceleration that it vibes.. dunno what it is, but i definitely feel it through my seat

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Thanks Fleurys. That sounds like my issue! So how much of a pain is it to replace u-joints? And also, how much did they run you?

 

- Al

 

The job in itself is not a complicated one.... just remove the driveshaft (make sure to note with paint the two parts before removing), then push out the old, push in the new, re-install the drivehsaft...

 

It all depends on the tools and place you have... Mine were rusted and almost seized... So it happened to be a bit of a pain since I only had a vice and a hammer. A good thing is that I had my friend to help hold the part while I was banging on it with the hammer... It turned out ok but took us about 2-3 hours to change 4 ujoints.... it's too much if you ask me....

 

but then on another ujoints job for a friend of mine, I rented a portable hydrolic c-clamp... and it made all the difference in the world... No more fighting for putting out or in the joint...

 

I think the front one cost around 22$ each... the back ones were about the same.... I say for 100$, doing front and back is a pretty good investment... don't buy cheap and have to redo the job a year or 2 down the road... The're good trucks... take care of it !

S.

Edited by fleurys
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Check the torque on your wheel bearings too. I had a weird vibration, turned out to be a "loose' right wheel bearing last guy in there did not tighten it down correctly. You most likely got it right, as your issue in only in 4 wheel but never hurts to make sure.

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Well, this is frustrating. I just replaced my front u-joints and went for a ride. The vibration seems almost worse, again at 35 and 55 mph! When installing the new u-joints, I made very sure to mark the flange-to-flange and yoke-to-yoke interfaces with paint for when I reassembled everything. Also marked front and rear of the driveshaft.

 

Back to my question in my first post: is it possible or has anyone heard of CV joints being out of balance? My wheel bearings are new and snug.

 

What the heck else could it be?

 

Thanks again for all your suggestions,

 

Al

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Could be a bad remanufacturing job. Someone posted a video on this site a while ago showing how they do it... wasn't exactly very precise. I would rebuild your OEMs now that you have them out (if they aren't actually badly damaged) and then swap them back in and see if it goes away... or you could try returning the remans if that's a possibility. This is just an idea, could be something else too...

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At that point, I would remove the cv axles and do a road test... this way you will confirm if it is them.... Then you can re-install 1 at a time and do another road test before putting the second one.... you'll eventually end up with the culprit...

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Fleurys - good point/suggestion. I guess it's OK to run with just one CV axle? Do I need to be in 4-HI *before* I start moving or will the transfer case be able to sync with just one CV spinning?

 

Thanks,

 

Al

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Start on 2hi, then shift on the fly like you would do nornally... all tests needs to be done on a straight line to prevent binding... obviously not an issue when you have no cvs, but important when both are there..

 

You can run on 4 hi with no cvs... it makes no difference... The transfer case will still engage and transfer the power to the diff through the driveshaft and turn the 2 cv flanges.... so you will know right away if it has anything to do with your driveshaft (ujoints) or cv axles...

 

Personnally, I would remove both to start and rule out for good the driveshaft-ujoints... if it still does it, then you know it`s not your cvs..etc...

 

running with one cv will not change or break anything... The open diff you have will simply send the power to the least resistance side, which on that case will be the side with no cv... so the flange will rotate faster than your underside but will still turn at the same speed as your rear wheels.. (like if you had your front wheel in the air or on a patch of ice)

Edited by fleurys
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Sounds like a loose wheel bearing to me. Jack up one wheel and grab the top of the tire and the bottom of the tire and push in and out and see if there is any play.

 

Now, just for clairification, this is from the owners manual....

 

2H — (2WD, high range) Only the rear wheels

are driven. Use when driving under the same

conditions as standard 2WD vehicle.

 

4H — (4WD, high range) Four wheels are

driven. Use when driving on roads where it is

difficult to drive in the 2H position (i.e., driving

at normal speeds on snow covered, icy, wet,

muddy or sandy roads).

The 4H position provides maximum power

and traction. Avoid excessive speed, as it

will cause loss of traction. Speed over 50

MPH (80 km/h) in 4H is not recommend.

4L — (4WD, low range) Four wheels are

driven. Use when climbing or descending

steep hills, or during hard driving in sand, mud

or deep snow. The 4L position provides maximum

power and traction. Avoid raising vehicle

speed excessively, as the maximum speed is

approximately 30 MPH (50 km/h).

N — No wheels are driven. Always keep the

transfer lever out of the N position. Shift the

lever quickly and smoothly when moving

across the N position with the vehicle stopped.

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Thanks 5523. As I mentioned earlier, I've checked that as other posts have suggested that may be an issue. Both my front wheel bearings are new and snug. No movement when grasping/rocking the wheel at 12-6 o'clock.

 

Thanks,

 

Al

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If you really want to confirm that the wheel bearings are OK and have no play, you need to take the drive flange off and use a dial indicator to see motion between the stub axle that holds the hub, and the hub. I once had my front left brake rotor grinding when making left turns. Ended up being that the bearings had just enough slack to allow the rotor to change angle slightly, and rub on the partially-sticky caliper.

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Well, I've found the issue or issues. I think I've been mistaking driveline vibrations for CV joint binding. With my Old Man Emu HD springs and the 9/16th spacer it seems my CV angles are high enough that the joint was binding when accelerating (front end lifts a bit), feeling like a vibration. For now, I've removed the 9/16th spacer to reduce the angle slightly. Reassembling was fine until...

 

I saw that the passenger side diff/axle-to-chassis mount was wobbling. The bushings on this mount are shot. That meant that if the mount allowed upward play of the diff it would then create an even more extreme angle for the CV.

 

Which brings me to my next (and hopefully final) question that I couldn't find an answer using "search": Does anyone know what this mount is called? And how much of a pain is it to remove/replace? I'll try to describe it. The mount sits perpendicular above the passenger side diff-axle and has two rubber bushings with metal-sleeves at each fore/aft mounting point to the chassis. It has four smaller bolts that connect to the top and rear flanges on the diff-axle. The FSM doesn't show this bracket in any exploded view.

 

Thanks again!

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