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NP242 front output bearing replace in jeep?
- Thread starter Desert4x4
- Start date
- Location
- Southern Maryland
yes but its a pain. Not sure its any easier on the bench though. From memory:
use pipe wrench to immobilize front yoke, and impact to remove lock nut on the yoke
open the case, remove the pump, yadda yadda
when you get to the main half, remove the lock ring on the front output gear, then pull it and the main shaft out together (while still on the chain)
at this point you should be able to pull the front output shaft out of the bearing
there is another lock ring holding the bearing into the front case half, which needs to come out
use pipe wrench to immobilize front yoke, and impact to remove lock nut on the yoke
open the case, remove the pump, yadda yadda
when you get to the main half, remove the lock ring on the front output gear, then pull it and the main shaft out together (while still on the chain)
at this point you should be able to pull the front output shaft out of the bearing
there is another lock ring holding the bearing into the front case half, which needs to come out
wizardPC
NAXJA Forum User
- Location
- Nolensville, TN
Any special tools required?
- Location
- Southern Maryland
decent set of lock ring pliers (not snap ring pliers)
The transfer case usually has one 10 or 13mm 12 point bolt up top in center. If you are changing it because you feel some play in the bearing, keep in mind replacement may turn out the same way. I have two Jeeps and in both the front output shaft has a bit of play at the bearing. When I installed a SYE in one of them I changed that bearing and found that the play is from how the bearing sits in the housing, not because the bearing had any play. It did have some roughness.
Oh interesting, thanks for the responses and help.
I'm trying to get rid of a high frequency pulsing vibration that occurs at 65+. Usually it is most noticeable starting at 75 mph. It is not related to engine speed or load. Definately only speed related. When the front driveshaft is removed, the vibration is gone. I replaced the driveshaft with a brand new one and new ujoints, also replaced the front pinion u joint straps. I'm wondering if a slight pinion angle misalignment can cause vibrations like this. The pinion looks perfectly straight, however according to my cell phone level, it appears that the axle pinion maybe be angled about .8 degrees above the driveshaft. I have adjustable uppers.
I'm trying to get rid of a high frequency pulsing vibration that occurs at 65+. Usually it is most noticeable starting at 75 mph. It is not related to engine speed or load. Definately only speed related. When the front driveshaft is removed, the vibration is gone. I replaced the driveshaft with a brand new one and new ujoints, also replaced the front pinion u joint straps. I'm wondering if a slight pinion angle misalignment can cause vibrations like this. The pinion looks perfectly straight, however according to my cell phone level, it appears that the axle pinion maybe be angled about .8 degrees above the driveshaft. I have adjustable uppers.
dan1977p
NAXJA Forum User
- Location
- Virginia Beach, VA
Since you have adjustable uppers, it's easy to test your angle theory. Just keep notes and adjust the length in small increments until you make it worse or better.
Good idea. Also, it is BS the idea of flipping the driveshaft 180 degrees to eliminate vibes right?I hear that a lot and can't imagine how it would ever help anything.
Ok thabks, I'll give it a shot also.
Is it possible there's a vibration on the axle or wheels that the front driveshaft transmits ?
Ok, so I flipped the driveshaft 180 degrees and no change.
Is it possible that mud tires, while humming on freeway, can also cause a pulsing vibration like this? Maybe the knobs on the tires just make the jeep vibrate? It might have gotten worse when I inflated the tires more. But removing the driveshaft made the problem go away.
Is it possible that mud tires, while humming on freeway, can also cause a pulsing vibration like this? Maybe the knobs on the tires just make the jeep vibrate? It might have gotten worse when I inflated the tires more. But removing the driveshaft made the problem go away.
- Location
- Southern Maryland
turn the front output yoke by hand and feel for slop and grit. You might be able to re-torque the nut and eliminate the slop but if its been able to move around it has probably damaged the balls and race
Thanks. It does have a slight bit of up-down movement. I tried to tighten the nut, but it's on there quite tightly. I'm mostly concerned if this is cause of the pulsing vibration.
- Location
- Southern Maryland
if you can figure out a way to mount a camera down there you can record a video of it at different speeds and look for vibration
Good idea. I did that with a rear pinion angle problem.
I just lowered the front tire pressure substantially to see if the vibration changed. Nothing. Maybe I'll mess with the front pinion angle tomorrow.
How sensitive is the front pinion as far as angles go? I suppose I should just accept that the proble, has to be the loose front output bearing.
- Location
- Southern Maryland
pinion angle is very sensitive, the double-cardan shaft essentially requires the driveshaft to be directly inline with the pinion or very near to it. If you're more than 3 degrees off its almost certainly the problem
- Location
- Southern Maryland
grab the slip joint where the two halves meet and try to rattle it with your hand. If the joint has any slop, it will cause vibrations. Probably the 2nd most common source after pinion angle. You might be able to pack it with grease and make the vibes go away but if it has run dry it is going to be worn and the whole shaft needs replaced.
- Location
- Southern Maryland
That kind of points to the bearing
The front output is only under load by the chain when one of the 4WD modes is selected. In 2WD the front output is disengaged from the mainshaft, still connected to the chain and spinning from the driveshaft, but not under load.
The front output is only under load by the chain when one of the 4WD modes is selected. In 2WD the front output is disengaged from the mainshaft, still connected to the chain and spinning from the driveshaft, but not under load.