2nd Gen Non-Engine/Transmission driveline whine

[metal tech]

I've had the truck since new, and it's always had a whine driving down the road. When backing up I get this nasty clunk like there is something loose, just as the clutch takes the slackout of the driveline. Since the noise is getting louder I pulled the D80 cover and the only "loose" thing was one of pinion gears(the one contacting the side gears). The side & pinion gears have grooves on the tooth face, I was told this is to hold oil. Since I can't clone myself so the clone could pinpoint the noise source while driving, anyone have some ideas. The trucks got 67,000, no heavy towing, and I use RP gear oil, std open diff case.



Al

 

[CumminsPower98]

If you suspect the noise is coming from the rear you might want to get some gear marking compound and check the gear contact pattern. There is a chance it was never setup right from the factory. Just yesterday I got done rebuilding a 9. 25 rear end in a '98 Durango. It looks like to me that it might have been setup wrong from the start as I was unable to find anything loose or any bad bearings. The pinion was too deep causing it to contact at the root of the ring gear teeth plus being out toward the heel. I was able to get the pattern where it belongs and it's completely silent now. Here are some basic differential instructions: http://www.differentials.com/install.html. If you scroll down a ways there are pictures of different contact patters and what's wrong. Below is a picture of the final runout from the Durango job I just did.

 

[metal tech]

Thanks for the pic. I checked the pattern yesterday w/prussian blue. It looks just like the one in your pic. I also checked the outer axle bearings and didn't find anything loose or the locknuts broken. I've already checked the obvious, transfer case output snap ring(still there), carrier bearing(just a little flex in the rubber), u-joint caps for grease(still in there). The front transfer case output is real sloppy. There is a big difference in the movement from the front and rear output yokes. I'm just going to pull the front shaft and see if anything changes.



Al