guys, ive been really enjoying my blazer, but last week i was driving home, and heard and felt somethign hitting up front. I got out and looked, and my left front axle was flopping around! it was loose as it went into the front differential. i took it to the shop the next day, and pulled the axle. The axle seal was completely shot, and there was a needle bearing that had fallen apart. Evidently, the previous owner had run the diff low-it had been leaking at the actuator? on the front of the chunk. I poured maybe 8oz of oil out of the front diff. It was rather dark, so im guessing it had probably never been changed. Well, i purchased a new needle bearing and seal and installed both, but i can still feel the axle moving as i turn sometimes, and you can stiil move it-not much mind you-as it goes into the diff. I know it is still moving a considerable bit, because it is leaking gear oil around the axle. What could be causing this? Is there anything that I might have missed? Is that seal the only thing that supports that axle?

I do have one more thing i need to ask-my truck as a 5" trailmaster susp lift installed, but i dont see any spacers on the axles-does it need some?

TIA everyone... I am truly baffled by this, and cannot figure out what would be the next thing to do to resolve this issue.

-Michael

 

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sorry about that...
if there's anything else i need to add, lemme know.

Thanks!

-Michael

 

bad race or bearing.

 

Are you sure that the axle is completely seated in the diff?
It's possible to install the axle partially, everything works, but the shaft is not installed far enough to create a positve seal at the oil seal.
Also there would be more play in the shaft if it isn't completely seated.

 

4lowlife, Which race or bearing? THe needle bearing is new, and as far as i know, thre isnt anything else that would support that axle besides that seal.

ChevyLover, I cant push it any further in than it is... i tried to pull it out and turn it a little bit, but it seems as though it wont go any further. one question-the nut that seats the needle bearing... is the bearing supposed to come flush with the face of the nut?

thanks again everyone...

-Michael

 

I just re-read your first post to refresh my memory. I'm wondering, with your 5" lift, if the angle of the axle is too extreme.
Also I've taken a diagram of a front diff to identify #1 - the needle bearing that you replaced and
#2 - the adjuster nut
I just want to be sure we're both talking about the same thing. As I say, the newest manual I have is for an '87. I haven't worked on a '99 for a couple of years.
If you're talking about how tight the nut should be....are you referring to what I have marked as #2?
#2 is the adjuster nut for the differential bearing. Turn the left differential adjuster nut sleeve in until there is a slight amount of backlash felt between the ring gear and the pinion.
In other words, tighten the nut and there should be a little play when you turn the front driveshaft back and forth by hand.
Hope I haven't made this confusing.



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from your diagram, i think we are on the same page. That unt is what holds that bearing in place, at least from what i can tell. there almost seems like there is too much play betweemn the axles, but it will not allow you to turn both axles the same way at the same time. I tightened that nut as tight as i could, and put the keeper back in its place.

I am afraid that the lift may be causing some extreme angles myself, but I dont know what i could do to change that. There is one more thing-the gear that the axle splines into, should it move at all? I can reach in with my finger and move it around, not just turn it. Is that normal?

sorry if i seem somewhat ignorant, but ive never had a 4wd truck before, so ive never had to work on a front diff like this.

thanks evryone!

-Michael

 

The only way that both axles turn the same direction is to turn the pinion (where the front driveshaft, from the transfer case attatches to the diff)
That unit (adjuster nut), that you tightened , is the left side of the backlash adjustment. There is an adjuster nut on the right side also.
Measuring backlash is a little more complicated. Backlash is the amount of play between the ring gear and the pinion. The nut that you tightened (as much as you could), should have just been tightened snug.

If your axle is not installed and you put your finger in the diff case, yes you can turn the gears....normal.

I wish I could see a picture of your axle installed....to see the angle and the stress on the seal.

 

chevylover, i will do my best to get you a pic of the axle tomorrow. There is one other thing that i did not mention.-you can curste me for it later, but i did not remember that the axle was installed sans the locking ring on the end of it. It got broken, and I asked several people about it, and they told me that it should be alright, so i installed it.

Do i need to back off the nut?

is there anything else that you would recommend?

thanks

-michael