Bearing questions

[graewulf]

Ok, here's the scenario:

95 ZJ

I have a growl from the front end that sounds like tires. I rotated the tires and the growl is still in the front end. I just replaced the brakes (while I was rotating the tires, saw they were about gone). I am figuring its a bearing going. I tried spinning the tires with the front end on stands and can't hear anything at all. When i hit a good bump on the road, it will go away for a second as the load is off the suspension.

I can see that the bearing assembly should be simple enough to remove. Is there also a bearing on the axle tube that I should be concerned with, or is it just the bearing assembly that un-bolts?

Any info or advice would be appreciated. I plan on taking it apart to replace the bearings on Sunday.

 

[dingus]

gee i thought i'd be asking YOU these types of questions! haha...

 

[xjpioneer]

Well there are the unit bearings which are the hub assembly which go bad and if that is the case then, yeah they are not that easy to replace. You have to unbolt them and you might want to spray them down with a good penetrating lube before you try to loosen, not required but it will be alot easier to pull them off and no broken bolts. It is a 12point socket MAKE SURE YOU DONT USE ANYTHING ELSE, or you will round it off. They hubs are an assembly with the bearings all in one so it makes it kind of easy to installed and they come prepacked with grease. They about 100 bucks each at the local parts store. If its not that then the only other bearings it the front axle is your bearings on the carrier in the differential. So check the hubs and if it not one then it the other. My bet is on the hubs, I had the same problem and thats what it ended up being.

 

[graewulf]

gee i thought i'd be asking YOU these types of questions! haha...

I may know quite a bit about cars in general, and Jeeps, but this is the first time I've had this part of a Jeep apart. I've done thses on other vehicles, but they used regular bearings, and had manual hubs, a whole different animal. Its awlays good to double check..

 

[graewulf]

Well there are the unit bearings which are the hub assembly which go bad and if that is the case then, yeah they are not that easy to replace. You have to unbolt them and you might want to spray them down with a good penetrating lube before you try to loosen, not required but it will be alot easier to pull them off and no broken bolts. It is a 12point socket MAKE SURE YOU DONT USE ANYTHING ELSE, or you will round it off. They hubs are an assembly with the bearings all in one so it makes it kind of easy to installed and they come prepacked with grease. They about 100 bucks each at the local parts store. If its not that then the only other bearings it the front axle is your bearings on the carrier in the differential. So check the hubs and if it not one then it the other. My bet is on the hubs, I had the same problem and thats what it ended up being.

Thanks, that is what I thought I would be in for.. 100 bucks? I wish... $209 each for the ZJ.. ouch. If one is bad, I might as well replace both since I'm pushing 172k... I'll spray them down tomorrow just to make sure the bolts will come loose on Sunday

 

[graewulf]

FYI: for anyone who may not have done this job yet. It really helps to remove the axle nut, loosen (but not remove) the 3 bolts holding the hub assy, then pry against the bolt heads (use a socket to keep from damaging the bolts) to loosen the rust first. The first hub we put the slide hammer on came loose with some effort, and left the inside half of the hub assy still attached to the Jeep. We pried against the bolts on the second one befoe using the puller and the whole assembly came out intact. Made it much easier to change.

 

[TwistedCU]

So, did that take care of the noise?

 

[graewulf]

Yup. the driver side bearing was on its way out. I could feel the flat spot once I had the assy out of the jeep. Much quieter now - apparently it was getting louder over time and I didn't notice it over the whine from the rear. I pulled the axles & checked the U-joints while I was in there, I figured if they showed any slop at all I was replacing them while I was there, but they were fine.

 

[bchcky]

i've replaced too many hub assemblies in my day. my method usually consists of:
- general prep (break lugs, jack up, put on stands, remove wheel)
- next thing i do is remove the cotter pin and crown piece and washer. have someone step on the brakes for you and remove the axle nut (a decent breaker bar is def helpful)
- remove brakes and support caliper (2 bolts)
- take bolts out of hub assembly (3) and hope that sucker comes free. if not, various methods work, the slide hammer as grae elected to use is a good choice, a hub puller works, but sometimes the assembly will separate into two pieces, which in the end wouldnt matter if you're replacing it anyways.
- swap and replace parts!
- this is also the method used to replace axle shafts, or get to u-joints in the shafts if you dont have cv's.

 

[Bounty__Hunter]

I've always had luck backing the three 13mm hub bolts out 1/8" at a time and hitting them with a hammer, being sure to protect the head of the bolt with a socket.

I wouldn't recommend slide hammers if you plan on reusing the hub.