Aargh!!! Driveline Noise???

:?
On the drive to work today, got off the highway and was coasting down the exit ramp, shifted to neutral and released the clutch had a rotational knocking type sound coming from what sounds like the right side going forward down front drive shaft. Did some more driving at lunch found noise to be present both when in gear and coasting but also when shifted to neutral, clutch in or out noise still continues. Anyone heard of, or experienced this? Gonna get it up in the air on a lift either tonight or 1st thing in the morning.
It's a rotational knocking/thudding like sound the at changes with vehicle speed not engine rpms.

 

Could just be a wheel bearing gone south.

 

Check ujoints, noise resonates thru the shaft.

 

We got it up in the air, nailed the noise down the t-case. In the process of draining the full synthetic fluid, pulling the inspection cover to check out the internals then re-filling with good old standard gear oil. This may be all my fault for putting in synthetic fluid. We'll see.

 

It's official. 2 broken teeth on the main shaft gear. 26 tooth 10 spline imprinted 18-8-49. Now off to the parts hunt. THanks for the input

 

What about the rest of the gears? You don't usually bust the teeth off of just one. If you get stuck for parts, try: http://www.jwjeep.com/ They are a Jeep dismantler here in N. Cal.

 

No other broken teeth in it. Got about 125 miles on it since getting it back on the road. Had some surface rust on a few of the gears think that may have been it, but not sure if one was cracked before. Didn't find any teeth in the case today just a bunch of shiny flakes in the oil. This gear maybe a pain in the arse to find. Not seeing any 26 tooth 10 spline gears yet.... Thanks for the link to check out.

 

Pics of the broken gear, plus another question..... How does the Mainshaft gear in my Dana 18, manage to be the correct part # from a Dana 20

 

yikes. would email herm about the gear as well.

 

Finally found the new part listed online last night. They used the 18-8-49 in both the dana 18 and dana 20 depending on the engine. The V6 with a T14 called for this gear supposedly from what I have been informed this morning after 5 parts request emails last night. Might have a line on a used one for 60.00 bucks but, if you have a box of gears to look thru Chuck I might be taking you up on that offer after work this week if possible.