BigDrizzle
NAXJA Forum User
- Location
- Fort Worth
My 94 2wd has a "whirring" sound coming from the rear. In suspecting that it's a bad pinion bearing. I'm having trouble finding part numbers for replacement. Any ideas or tips?
-
Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.
Bad pinion bearing? Need help, new XJ owner
- Thread starter BigDrizzle
- Start date
8Mud
NAXJA Forum User
- Location
- Central Germany
Pinion bearings can be kind of iffy to change. I wouldn't do it on a hunch.
First off most times when they go bad the seal leaks, is your seal leaking?
I wiggle the yoke side to side, slap the yoke with the palm of my hand. You can feel the play if the bearings are very worn. Sometime it even clicks.
You can take the drive shaft out, the tires and drums off and slowly turn the yoke by hand. You may be able to feel the rumble.
While you have the drive shaft out you can inspect the u-joints.
Pop the cover off of the differential and inspect the gears (ring gear and pinion), the spider gears and the thrust washers.
Try prying up on the carrier (a rag and a pry bar), if it moves at all it is likely the carrier bearings are worn.
Try moving the axle shafts up with the drums off, check the seals for seepage. The axle bearings, in my experience are relatively loose anyways (more than the common few thousandths of play in other bearings), it can be hard for a novice to tell normal loose, from too loose. In and out play on the axles doesn't mean much in my experience.
Sound in the drive train can fool you. As often as not where you think you hear it and where it actually is aren't the same place. I've known veteran mechanics to change the wrong bearings, believing the sound to be coming from someplace it wasn't. I've gone down the wrong path many times chasing a noise in the drive train.
First off most times when they go bad the seal leaks, is your seal leaking?
I wiggle the yoke side to side, slap the yoke with the palm of my hand. You can feel the play if the bearings are very worn. Sometime it even clicks.
You can take the drive shaft out, the tires and drums off and slowly turn the yoke by hand. You may be able to feel the rumble.
While you have the drive shaft out you can inspect the u-joints.
Pop the cover off of the differential and inspect the gears (ring gear and pinion), the spider gears and the thrust washers.
Try prying up on the carrier (a rag and a pry bar), if it moves at all it is likely the carrier bearings are worn.
Try moving the axle shafts up with the drums off, check the seals for seepage. The axle bearings, in my experience are relatively loose anyways (more than the common few thousandths of play in other bearings), it can be hard for a novice to tell normal loose, from too loose. In and out play on the axles doesn't mean much in my experience.
Sound in the drive train can fool you. As often as not where you think you hear it and where it actually is aren't the same place. I've known veteran mechanics to change the wrong bearings, believing the sound to be coming from someplace it wasn't. I've gone down the wrong path many times chasing a noise in the drive train.
8Mud is spot on here.
You have to take the whole differential apart to change the pinion bearings. And if you're going that far into it, its often a good idea to change all the bearings. Parts depend on which axle you have, D35, 8.25, D44 all take different bearings. Many times its easiest to buy a rebuild kit for your axle. You would need tools to pull the carrier and inner pinion bearing off, dial indicator for backlash, driving them back on, beam type or Torqometer torque wrench for measuring rolling torque, and if a 8.25 a tool to set the side adjusters. Setup bearings may come in handy too. I would google "setting up a <insert your axle type> differential" to see if ts something you want to do the first time or just pay someone to do it.
I have been dealing with some driveline noises that are actually driveshaft related. Its amazing what a rebuilt driveshaft that has been balanced feels like compared to one that is out of balance.
You have to take the whole differential apart to change the pinion bearings. And if you're going that far into it, its often a good idea to change all the bearings. Parts depend on which axle you have, D35, 8.25, D44 all take different bearings. Many times its easiest to buy a rebuild kit for your axle. You would need tools to pull the carrier and inner pinion bearing off, dial indicator for backlash, driving them back on, beam type or Torqometer torque wrench for measuring rolling torque, and if a 8.25 a tool to set the side adjusters. Setup bearings may come in handy too. I would google "setting up a <insert your axle type> differential" to see if ts something you want to do the first time or just pay someone to do it.
I have been dealing with some driveline noises that are actually driveshaft related. Its amazing what a rebuilt driveshaft that has been balanced feels like compared to one that is out of balance.
