Help...I have a big rear end problem😀

[GatorDoc]

Hey guys,
I have a 75 bronco that I have mostly restored. Over the past year I have been getting a terrible noise with acceleration especially right around 40 mph. I have had the transmission rebuilt ( for a different reason but no effect on the noise), the transfer case ( figured while I was at it). The output shaft on the transfer case was bad and it quieted down some but still lots of noise. Here is actually a link to a video of the noise. Notice the increase in ?metal noise? around 40mph.
https://www.youtube.com/watch?v=Rmwl-cln5zg
I have had drive shafts checked, new U joints, etc.... No change. My transmission guy, who is very good, thinks it is the rear end. We have rebuilt everything else and the noise did start about 6 months after having the rear/front gears changed to 4:11's ( he didnt do it someone else did). He thinks it may have been shimmed incorrectly. But I have been super busy therefore put it off and only driving my Bronco very little.
Fast forward to today, I was chasing a leaking brake line and stumbled upon a different type leak on the right rear wheel. It appears that the axle seal may be bad as everything ( including the brakeshoes) were covered in a thin brownish grease. I do not think I have every replaced them,so I remove everything ( luckily the axle came out very easily. The seal appeared intact, bearing looked OK, I didnt note any groove, the vent is not clogged BUT.....I found this in the gunk in the axle housing. I looked over the bearing closely and it does not appear to be from it as it is still intact. My plan is new bearings/seals/axles and brakes but looking at these metal pieces and considering the noise, would you open the rear end? I have never worked on one so am a bit leery. I would certainly appreciate all comments, input, advice, etc.. I also would appreciate any advice for upgrades to the axles, axle seals etc...
And thank you in advance.
G

 

[bronkenn]

Sorry to hear that.

 

[76BroncoPete]

Another big rear end problem

 

[ScanmanSteven]

The Ford 9” is one of the easiest to set up and work on. The pieces look like brass (?) but I don’t remember any brass parts. I would drain the fluid and pull the center out. This way you’ll be able see/hear what’s going on or throw it in your truck or trunk and take it to your mechanic, or tackle it yourself.

 

[GatorDoc]

That may be the flash making them look brass. They are more like aluminum or very thin steel, Once the axles are removed does the center come out pretty easy? I guess I need to research it more. And is the center gearing shimmed while outside of the rear end or once its back in? The reason I ask is I may have to take the entire rear end back in to the mechanic.
At first I was thinking they may be parts from a previous rear axle bearing that was busted up and removed. But we have owned it since new and I dont remember the bearings ever being changed. Also with closer look you can see the stress cracks on the metal.
Thanks to all of you for the help so far, especially those of you with your own big rear end problems. Here in South Georgia it seems to be of epidemic proportions

 

[spap]

I’m still cracking up from the title haaa

 

[SP73]

I’m still “crack”ing up from the title haaa

Fissed it for ya ^!

All joking aside, and back to the matter at hand. I’d say r&p for sure. You might want to look into a new turn signal switch too, unless you were doing 40 mph through that right hand turn!

 

[GatorDoc]

Yeah, I left the blinker on. Automatic blinkers in cars today have made me lazy. Interestingly the "metal" noise is only under load with acceleration. That always made me think tranny or transfer case not rear end. I would think the rear end would make noise anytime it was moving not just during acceleration over 40

 

[Cortez]

Just gonna say what everyone else was thinking when the video started...sweet exhaust tone brother! Good luck with the fix.

 

[Broncobowsher]

Pull the 3rd member out. Something evil is happening inside. I am thinking once you have it out you will be questioning how it was ever driving.

 

[bax]

I dont understand the brass , like scanman has said. another way to get a look at your gears is to pull just the pinion support out. Its pretty easyt to get out and its easy to put back. Only tricky part is to retain any shims on the support. make sure they go back. You can suck out the oil and get a good look at the gears. You can also check out what might be laying in the bottom of the housing. Easier than pulling the gear case. No axles have to come out to do this.

 

[Broncobowsher]

He stated they are not brass, just what the camera flash did.

If that made it into the tubes, there is a lot more in the bottom.

 

[GatorDoc]

Thanks Cortez. I am running a hopped up 302 with 351 heads, a off road H pipe and flowmasters. I am afraid I am leaving my carbon footprint and there is no sneaking up on anyone.
I have decided to take it to the mechanic and get some professional help. I will get back with everyone and let you know what I found. Thanks again
J

 

[Boss Hugg]

So let me get this straight... You're concerned about a strange noise coming from your big rear end???

What type of differential is it?

 

[jonpblewis@yaho]

Did someone Say Big Rear end Problem?https://www.youtube.com/watch?v=_JphDdGV2TU