CV joints

[PATRICKH]

Do the front halfshafts/cv joints turn even when the truck is in 2 wheel drive?

[HenryJ]

Yes, but they are not driven. The "free wheel". The transfercase is not engaged and the lock collar for the right axle is disengaged. The driveshaft should turn freely by hand. Each tire can turn independently without binding.
While the driven end of the shaft is free , the wheel hub is directly attached to the end of the half shaft. As the wheel turns so does the half shaft as it is driven by the tire.

[PATRICKH]

Ok, thats what I thought. I'm still chasing a vibration that kinda acts like a cv joint, but none of the usual clues are there. (no clicking in turns, no noticeable movement when i try to pull on them) The vibration is mainly above 60mph and it really does it when I let off the gas to slow down from freeway speeds. Anything under 60 and there are no issues.

I've replaced ball joints, tie rod ends, both front wheel bearings, shocks, tires (they've been rotated and balanced 2x) and all the brake parts (calipers, rotors, pads and all hardware) have been replaced.

The rear u joints were replaced in 2010, but going to look at them now. I'm stumped.

[HenryJ]

Deceleration changes the loading of the pinion bearing. Check the rear axle pinion nut to make sure it is tight. Mine was loose and sounded just as you describe. A quick search should reveal my swap, pictures and the squished pinion bearing shims. Suspect the worst if your pinion is loose. Might be time for the ZR2 rear swap?

[PATRICKH]

Yeah, think we talked about that before. Noticed that there are several at our local pick a part yard. Good Saturday project.

[killian96ss]

You could try unbolting the driveshaft, rotate it 180 degrees and reinstall. Sometimes this helps with driveline vibrations.

Steve

[PATRICKH]

Yeah, did think about that one, going to do that tomorrow and go from there.

[ApproachMedium]

Do our driveshafts have any weights stuck to them for balancing? My old 92 lost one, and boy did that take us forever to figure out... Pretty much did the same thing.

[PATRICKH]

Yeah, there are a few. depends on how out of balance they are. I checked mine and didnt see where any were missing. I tried to tighten the pinion nut but vibration was the same. I rotated the shaft 180 degrees and it seemed to change the speed at which the vibration started, but still there. I'm gonna check into getting it balanced and see what that does.

Oh yeah, gotta see about getting the drivers side top door hinge rewelded too. Never ends.

[killian96ss]

Are both u-joints still tight on the driveshaft? Even a little play will cause vibrations. If rotating the driveshaft changed when the vibration comes in, you are probably on the right track.

Be careful tightening the pinion nut as you can pretty easily exceed the recommended pre load on the pinion bearings. You must check the inch pound pre load after each 1/4 turn of the nut. The bearings are pretty durable, however too much pre load will cause them to heat up which leads to many problems.

Steve

[PATRICKH]

Yeah, learned about the pre load on here, so was aware of that. I had the u joints replaced last winter, wanted to do them myself but time off work wasnt an option so had them done. I did notice that the rear u joint has a zerk fitting and the front does not. Which makes me think it wasn't replaced. Gonna knock that out this weekend along with getting the door hinge welded.

Part of the fun driving a CC with 197,000 miles on it !

[killian96ss]

The factory u-joints do not have zerk fittings and are held in place by nylon injection. Replacement u-joints are held in place by snap rings. I prefer the greasable u-joints over the sealed type since you can flush out old grease and contaminants. The only problem is access to the zerks which sometimes requires a low profile coupler or needle extension.

Steve

[PATRICKH]

Yeah, thats what led me to believe that the front one may be original. Which would most likely be my problem. Can't wait till this weeks shift ends and I can get to it...

[Lil-j]

Did you get this resloved? I've got a similar issue, the vibration at first was only noticable at high way speeds. Now it's noticable from as soon as 20-25 mph, all the way up and down. I went the same route you did, alot of new parts on the front end, 2 new wheel bearings in the rear end. Pinion bearing is tight, I've rotated the drive shaft 180, u-joints appear fine, no play there. Not missing weights on the drive shaft......Tires would be next, but I dont want to spend the money with out really needing tires....Never ends!

[_STUCKY]

I prefer the greasable u-joints over the sealed type since you can flush out old grease and contaminants.

I prefer non greasable u joints for 1 reason.... They are solid. Arguably stronger than hollow grease able joints.

The rear u joints were replaced in 2010

I'd replace them, with Dana if you can find them. It's almost 2013!

[PATRICKH]

@Lil-j....No I have not gotten to it yet, pulling quite a bit of overtime at work. Out the door at 6am not home till 9pm for almost 3 weeks straight. Going to hit it this weekend, will post asap. I agree it never seems to end, LOL

@_STUCKY... Dana is the only way to go!

[_STUCKY]

This is why I don't care for greaseable u joints. A stress crack forms at the hole for the zerk. A greaseable u joint is only good if you grease it.

[F9K9]

..........@_STUCKY... Dana is the only way to go!

Don't you means Spicer?

[_STUCKY]

..........@_STUCKY... Dana is the only way to go!

Don't you means Spicer?

Dana. Spicer. Same thing.

Neither of the u joints in the picture above are Dana/Spicer. Both were different brands, same style, same measurements, same breakage, both were cold forged. We swapped one of those out last night for a hot forged greasable u joint with the zerks on the caps. My buddy has been popping a u joint almost every time he takes the jeep out. I guess it's not too bad though since he got the chromoly shafts. He was snapping shafts before. The only reason he finally got the chromolys was because we couldn't find anymore scout II shafts locally.

[PATRICKH]

NOW THATS NASTY! Still have not gotten to the joints, got a day off, wifes grandfather passed away..

Think I'm cursed.

[_STUCKY]

Today I noticed that my passenger side CV shaft is slinging grease....

Let the searching commence...

[ApproachMedium]

I had the same problem. Driver side went, then pass side. I think I paid $60 a piece for each half shaft at NAPA.

[_STUCKY]

After doing some reading, I'll find some hose clamps. But that's good to know that they are only about $60. Are they the same part number for both sides? Do you have the part number? I wonder how cheap I can find them...

[ApproachMedium]

They are different for both sides if I remember correctly, one is longer than the other I think. I just replaced mine because a friend told me that if any dirt etc gets inside and fouls up the grease the joints will go. So to save myself from doing the job twice, at 60 bucks I said who cares. Napa also takes back your old one and returns a core charge of like 5 or 10 bucks.

[Horsehammerr]

Today I noticed that my passenger side CV shaft is slinging grease....

Let the searching commence...

If it just slipped of it's seat , get a tube of grease and reload it. Throw a hose clamp on and go. If it's torn or split it's a bigger job to take it apart to put new boot on. Complete tear down of that side to get the axle shaft out. Mine split so I decided to do both sides, all four boots. I hose clamped all and replaced all ball joints and complete new steering linkage. Polyurathane bushings in upper control arms and both bilstein shocks.

[_STUCKY]

So I broke a non greasable u joint. I had really abused the jeep Saturday night. Sunday I pulled it off the trailer to see that my rear passenger side tire had come off the bead over night, so I just parked it by our shop, out of the way. Monday I took the tire off and fixed it and drove the jeep out into the cow pasture where we had been working. I parked it by the pond out of the way. A few hours later, I needed to run up to the shop to grab some wire. So I hopped in the jeep and went to back up. It literally sounded like a can of soda opening! "POP!"



It sheared 2 of the crosses clean off and in that picture looks as if the caps are falling out. It currently sits in shame.

That is not a Dana/Spicer u joint, probably a precision or whatever the napa house brand is. I'll be replacing it with Dana/Spicer.

That u joint took some serious abuse in its life time. It's probably been in there for 2 years, with nearly all of it being offroad, under constant abuse. I wasn't surprised when it popped, disappointed perhaps, but not surprised. I have no idea if it had any play in it before breaking.

[F9K9]

Looks like your ears are stretched on the axle shafts. Mark them when you install the new ujoints or tack weld the caps to check for movement.

[_STUCKY]

I replaced it today, I'll mark it tomorrow. A couple of the clips were gone. The caps and needles were dry as could be and rusty. The shafts looked fine, though. I've got spares

Edit: it didn't get a Dana/Spicer I had a precision non greasable u joint sitting there, so that's what it got.