Conversation Between Kajtek1 and trialnterror

I think you should take it to the forum for better exposure. Sounds like you have something going inside differential, but pictures would be really helpful. Good luck

Hey I see your knowledgeable on rear ends! I had 456 gears put in from 373 in a 99 ford f250 SD it had a vibration at 70 bad rumble! Then I hear ringing so the guy tells me it the driveline! So I see wetness where the rear drive line goes into the rear axle (rear axle bearing?) so I go to jiffy lube and tell them to check the level! When they take the nut out it has shavings all over it and in the fluid! My question to u if u don't mind is- 1 I'm assuming this is not right! It's only been about 800 miles and 2 months so what should I tell the installer at six states? Demand new gears new axles? He wanted to change the driveline but it's a 3 1/2 tube and I think the problem is in the rear?