'98 EXPY 4.6 rear axle flange vibration

[edmockta]

I recently (approx. 2 months ago) had a local shop change out both rear wheel seals and recently ( about a couple of weeks) I've noticed an annoying hum/whine/slight vibration only when I accelerate. When I let off the gas it doesn't make any sounds.
I jacked the rear end up removing both tires and put in drive. I noticed the sound was coming from the drive shaft end of the rear axle at the flange. Prior to this I rotated the drive shaft while in neutral and noticed some play at this same spot.
Does anyone if the flange that bolts to the drive shaft goes bad? I hope I don't have to replace the whole rear axle.
Any help (trouble shooting tips) is greatly appreciated.

 

[CaperCanadian]

It almost sounds like the bearing might be bad, do you know if they removed the pinon gear, and if they did, did they install a new crush sleve. that would cause a bit of play there and put more strain on the bearing causing it to fail.

 

[stamp11127]

You only need to pull the axles to change the wheel seals. Check that the rear end dope is at the correct level and for giggles I would grease the u-joints if they have the zerk fittings. If those are fine you can usually check the pinion bearing by unloading the rear end(on jack stands), put trans in neutral and wiggle the flange up/down & side to side. Also watch the u-joint for slop.
If the flange clunks, head to the beer cooler and toss back a few....

 

[edmockta]

It almost sounds like the bearing might be bad, do you know if they removed the pinon gear, and if they did, did they install a new crush sleve. that would cause a bit of play there and put more strain on the bearing causing it to fail.

Im not sure what was done since it was a drop it off in the am and pick it up in the PM.

 

[edmockta]

You only need to pull the axles to change the wheel seals. Check that the rear end dope is at the correct level and for giggles I would grease the u-joints if they have the zerk fittings. If those are fine you can usually check the pinion bearing by unloading the rear end(on jack stands), put trans in neutral and wiggle the flange up/down & side to side. Also watch the u-joint for slop.
If the flange clunks, head to the beer cooler and toss back a few....

I didnt find any zerk fittings and at the moment I have the drive line disconnected so the rear axle is free.
So if the flange clunks does that mean a lot of cha-ching to repair/replace the axle?

 

[stamp11127]

If you have someone else do it they usually run around $800+ depending on what is changed.

Also see if the flange has any play front to back (in or out).

A little whine doesn't mean you have to run out a fix it today. When it starts sounding like R-R-R-R-R-R and you can't talk normally it would be a good time to fix it. We had an old pos dodge van at work that should have tossed the rear end out of it years ago. It has a very loud R-R-R-R-R noise that is so bad you have to yell to carry on a conversation while driving. It is still trucking down the road today - just can't sneak up on anyone.

 

[edmockta]

You only need to pull the axles to change the wheel seals. Check that the rear end dope is at the correct level and for giggles I would grease the u-joints if they have the zerk fittings. If those are fine you can usually check the pinion bearing by unloading the rear end(on jack stands), put trans in neutral and wiggle the flange up/down & side to side. Also watch the u-joint for slop.
If the flange clunks, head to the beer cooler and toss back a few....

I now have the drive line disconnected from the rear axle and the flange does has some movement; up and down/in and out. Is this normal play or something bigger like a rear axle replacement?

 

[stamp11127]

You shouldn't have any movement that is noticeable by hand, should only show with a dial indicator.

Rebuild or boneyard replacement. I would go the rebuild route. You can do it yourself with the proper tools. Check youtube for videos so that you know what is involved.

 

[edmockta]

You shouldn't have any movement that is noticeable by hand, should only show with a dial indicator.

Rebuild or boneyard replacement. I would go the rebuild route. You can do it yourself with the proper tools. Check youtube for videos so that you know what is involved.

Good to know. Before removing the driveshaft I was able to rotate the line clockwise / counter clockwise.

Can you tell me what parts I need to buy (like rear axle differential rebuild)?

Thanks for all your help.

 

[stamp11127]

Watch the videos first then see if you want to do the rebuild.

https://www.youtube.com/watch?v=lV-n3GFOd7k

There are a few others that are worth watching, if you don't set it up correctly the gear set won't last long.