Pinion flange (rear) making metallic noise - do I need new 3rd member? (1 Viewer)

[smalltown]

Hi All
Was hearing a metallic noise coming from under vehicle. Disconnected the rear driveshaft to start troubleshooting. Noticed the pinion flange was wonky - see video below. Maybe instead of 'wonky' I should be more specific. It appears as if side of the flange that is, I think, supposed to be tight up against the 3rd member is spinning freely. This is causing a rattle when I drive as the shaft/spline spins and the loose metal flange also spins freely. It does not make any other noise, so no whining, no grinding, etc. Just the metallic clinking of the loose flange bit.

There is no real play in the pinion bearing...though there is a little leak that I will fix.

Not sure what is happening here. Hoping not to have to replace / rebuild diff...

Is my pinion bearing shot? Is my diff ruined? Could this be somehow caused by insufficient grease in the slip yoke?

Any thoughts? Thanks so much for any advice.

 

[smalltown]

Hi All

After some searching, this part moving around is just the dust cover of the companion flange (I think). Is a loose dust cover something to worry about if there is no play in the pinion flange / bearing? Or is a loose dust cover indicative of a larger problem? Or can I just somehow affix the cover or replace it?

thanks

st

 

[SteveH]

I believe the dust cover is pressed onto the flange. You might do well to remove the flange, buy a dust cover, and install it. Your old dust cover might still fit on the flange, but prying it back on their with the flange installed will be difficult or impossible. You could also cut off the current dust cover and leave it off. But, it's there for a reason.... so replacing it is best.

 

[smalltown]

Hi @SteveH
Thanks for the reply! I've ordered a replacement dust cover. Will take off the flange, replace the seal while I'm there as well.

st

 

[SteveH]

When you remove the pinion nut, pay attention to the pinion nut tightness and retorque it to the exact same location where it started (same # of threads sticking out, location of stake on the nut, etc. You don't want to change the preload on that nut while doing this service. Also, check your axle vent (pry off the cap) and be sure the rubber disk is dry and not welded to the stub on the axle, or attach a 3/8" fuel line to the stub and run it up high. This will prevent pressure in the axle and future leaks.

 

[smalltown]

Thanks also for that! I have been wondering about diff breathers for awhile...

 

[smalltown]

Dear All

sorry it's been some time. So...because of work I had to leave the truck for a bit. Here is a video of the pinion flange once I took the dust cover and seal off to replace the seal. So much play. Is this normal?



I drained the diff oil and there was quite a metallic sludge attached to the drain plug. No 'chunks' but still metallic. Wondering if I need just to replace the third member??

If I do replace the third member, can you recommend a parts dealer?

Thanks!

st

 

[Earwigg]

Mine was/is making that noise took ages to figure out what it was. Caused by driving through long grass which got all tangled up.

 

[smalltown]

Here is a pic of the drain plug...

 

[cruisermatt]

That metal on the drain is normal. Gear mesh normally makes small particles like that. That’s why the drain plug has the magnet.
as for the play you asked about with the pinion shaft, that is normal because the flange is removed, therefore removing preload (and support) on the bearings.
When you take the seal off you can pull the outer pinion bearing with your fingers and look at it, but no immediate need for a new third member

 

[smalltown]

Thanks so much for the information @cruisermatt! Much appreciated. Will re-attach the drive shaft and give it a go.