Topic: Dual cause hum/howl

[Nimyad]

Ok, I just got done putting in my duals, stock gears in both cases. Both cases were in working order. But now above like 20 mph either the crawl box or transfer case starts to do a howl, it's the worst around 30 mph then it gets quieter but can still be heard up to free way speeds, doesn't get louder at freeway speeds though. Any ideas where the howl is coming from?

[twistedtoy92]

is it fullllll of oil?

[Nimyad [OP]]

Yeah filled, started and let spin for about 5 minutes checked and filled again, then hooked up driveline, drove about 10 miles then checked and filled again

[Nimyad [OP]]

Ok so drove it some more. The sound is like when you spin metal inside of another metal sleeve, that high pitched weird noise. It mostly does it when decelerating

[crazykooter]

It could be your output bearing on rear case.  You can pull the rear part of tcase, then remove the lock ball, then the 2 speedo drive gears.  After that the output bearing will come off.  May take a few a little prying but it will come off.

[79coyotefrg]

sounds like a thrust washer didnt get a snap ring

[Nimyad [OP]]

Well I was thinking it was a bearing but there's no consistency to it. It'll be there one minute then go away for about 10 seconds then come back, sometimes it's quieter sometimes it's louder.
All snap rings were installed, the rear case is 100% factory never been opened, less then 100k miles. The crawl box has 170k miles on it, bearings were fine. The only thing I could think is that I had to switch the flanges on the rear case, could putting them on to tight cause this?
Also I finally decided what it sounds like, it's the same sound and pitch as when your ears are ringing

[PhantomD aka Zach]

main bearing...

had a very similar issue, check the double row bearing, probably ate the cage and is creating all sorts of havoc...

but seriously, pull the cases apart until you cause more damage.

[Nimyad [OP]]

Ok lifted up the rear tires and took it up to speed. Found out it's the rear ring and pinion not the t case thankfully. So I'll tear into that this week sometime

[Japjeep]

r u running a rear cv driveline?

[Nimyad [OP]]

Nope

[Japjeep]

i just did the same thing and my cases sounded like they were going to grenade (but only after installing duals)when i let off the accelerator after 40 50 mph. after info, replaced ujoint with cv and noises all gone! weird! but actualy turns out pretty comon.