Grease Section of front Driveshaft.

Grease Section of front Driveshaft. and popping sound.

Sorry i dont have any pics right now as im at work, and i dont feel like going out there to get some with my camera phone. I can provide them in about an hour and a half when i get home if need be.

Stock height 90 XJ 4.0 NP231 dana 30F/35R.

My question is this:

The front driveshaft on my XJ has a zerk fitting on a "ring" that is for the slip-joint (sorry im a drivetrain newb).

I remember awhile back that i went to grease it, and the fitting came loose. I was able to get by with just holding it tight, and greasing it again, but if i grease it more it will come loose again. Last time i looked (the other day) it hasnt moved...
How can i fix this? Get a front drive shaft at the junkyard?

Thanks

EDIT:

The biggest reason why im looking into fixing this is because right now when braking, i get a small "popping" sound that seems to be right below me towards the engine bay. I only hear it when braking, and not every single time i brake. So im trying to fix something that "could" be causing it.. although i doubt its that. Any ideas what the popping sound could be also?

Thanks again!

Ok i know my explanation skills suck most of the time .. so anyway here is a clear pic of what im talking about:


Its not from my Jeep, just found it searching around.

If your fitting is loose and you get a noise comming from that area,most likley your slip yoke is worn out.

it's just a rubber boot to keep the grease in.
if the shaft doesn't wobble side to side at the slip I wouldn't worry about it.

the popping noise under braking is morelikely control arm bushings, or the trackbar mount.
do you feel it in the floor?
if so I would be worn out control arm bushings.

87manche said:

it's just a rubber boot to keep the grease in.
if the shaft doesn't wobble side to side at the slip I wouldn't worry about it.

the popping noise under braking is morelikely control arm bushings, or the trackbar mount.
do you feel it in the floor?
if so I would be worn out control arm bushings.

Click to expand...

No i dont feel it in the floor .. but i "think" that i feel it in the brake pedal. I dont know if my mind is making me think that i feel it because i hear it.. or if i actually feel it. If i am actually feeling it, its hard to feel.. you can hear it much more then you can feel it...

Ill check to see if my "shaft" wobbles (pun intended).
Is there a easy way to check the control arm bushings and/or the trackbar mount? Can you help me identify these things ... im pretty sure i know what the control arm is (goes from the frame to the axle right?) but the trackbar.. what does that look like? Again im sorry, im just a newb when it comes too drivetrain components.
Thanks for the info...

you are correct about the control arms.
They hold the axle to the Jeep. You have upper and lower control arms for a total of 4. To check the bushings you need to jack the jeep up so that the axle is hanging with no weight on it, then see if you can move the axle by hand, looking for any slop or movement.

The trackbar is that big bar that comes from the drivers side frame rail to the passenger side of the axle, it locates the axle side to side. Same procedure to check that, and make sure that you check the torque on the frame side bracket that holds it. They tend to come loose and make all sorts of pops and cracks.

87manche said:

you are correct about the control arms.
They hold the axle to the Jeep. You have upper and lower control arms for a total of 4. To check the bushings you need to jack the jeep up so that the axle is hanging with no weight on it, then see if you can move the axle by hand, looking for any slop or movement.

The trackbar is that big bar that comes from the drivers side frame rail to the passenger side of the axle, it locates the axle side to side. Same procedure to check that, and make sure that you check the torque on the frame side bracket that holds it. They tend to come loose and make all sorts of pops and cracks.

Click to expand...

Thanks... When i have my axle drooping to replace the oil pan gasket (again!) that should be a good time to check these things right?

Another thing to check is the u joints in the axle and front/rear drive shafts. I had a similar problem a while back and would only make the noise when braking hard it was a bad u joint in the rear shaft. All of the needle bearings had come out and it was moving around inside the cap.

Well when i had the axle hanging, there was absolutely no movement. The UCA / LCA bushings looked cracked, so i bet they could be replaced. The Track bar bolts were all tight to spec except for the two that are accessed via the fender well. They turned about 1/4 of a turn tighter till they reached the proper torque. While i was down there this weekend, i also broke out my grease gun and lubed every zerk i could find. I also used my needle adapter to shoot some grease in the double cardan. I'm still having the problem with the popping. Could it really be the bushings in the control arms?

How hard are they to replace? What else could i check for? Could loose bolts in the steering box cause this popping also?

Thanks for your time.

Muad'Dib said:

Well when i had the axle hanging, there was absolutely no movement. The UCA / LCA bushings looked cracked, so i bet they could be replaced. The Track bar bolts were all tight to spec except for the two that are accessed via the fender well. They turned about 1/4 of a turn tighter till they reached the proper torque. While i was down there this weekend, i also broke out my grease gun and lubed every zerk i could find. I also used my needle adapter to shoot some grease in the double cardan. I'm still having the problem with the popping. Could it really be the bushings in the control arms?

How hard are they to replace? What else could i check for? Could loose bolts in the steering box cause this popping also?

Thanks for your time.

Click to expand...

For shits and giggles i tightened up the bolts for the steering box last night. So far it seems to have stoped that popping while braking.
Thanks for all the help.