Odd Clunking Noise

[01 Dually]

Hi,
I'm new here. I have an 01 dually crew cab 4x4. 1st question is how do I enter or attach my truck photo?. 2nd,My problem is lately I have this clunk when I back up which sounds like it 's from the rear. It sounds like a bad or frozen u-joint and gives you that kind of jolting feeling but I already replaced the rears. You can hear and feel it while sitting in the truck. I'm still looking and having it checked out this weekend. It only has 46k on it and is garaged most times. Could it be calipers? The rear end ? or worse (Which I hope not) ,Has anyone had a similar problem or an area for me to check? Thanks

[super_stroke]

picture posting help------->HERE<-------

as far the clunk, i dont know.

[Lone Ranger]

Hello 01 Dually!

Look, hopefully one of the Techies will come to your rescue better than me... But I did a lot of custom work to my older 350 years ago... That rear diff is not likely to be the problem, big carrier bearings, big ring gear, huge pinion gear, that sort of thing. If your transmission is not leaking, no rear seal leak or discoloration in the fluid, the reverse clutch pack is not likely.... I would look at springs, and or calipers, it is probably something silly there. I remember years ago, I did have a caliper that the cups were a bit hard to push in, a little corrosion, possible binding up and not releasing, possible...

One more thing, there was an LSD clutch pack in most of the F-350's. If you were backing up not straight, but on a turn as it angled around, one wheel is turning more than the other, and I have seen one that made a bit of a clunk as the LSD Limited Slip Diff clutch pack broke free. But all these are vague guesses...

Hope I have been a little help.... Don't worry, it does not sound that bad and is probably something silly, but an undefined clunk one cannot here or see is a tough one to guess for anyone.... Regards, Ranger.

[Lone Ranger]

One more thing, if you did not get it from new, and it had a Detroit Locker in it, they are a mechanical locker that was famous for breaking free with a clunk as it went around corners.... Like backing in on a angle, clunk! I had one and it startled me a little once in a while... Dog teeth over riding a spring loaded cog sort of clunk. In my case perfectly normal... My

[Lone Ranger]

One last one more thing, ( I am having a slow afternoon).... Go under if you have a Crew Cab, and have a shake of the driveshaft at the mid shaft carrier bearing. Could be loose and only showing up in reverse?
all right, I'll shut up now and go to my corner, if none of these I don't have a clue... Probably true.. Ha!

[01 Dually]

Thanks ,
I think my photo is up now. I forgot to mention it is an automatic and both oil & trans pans and rear seals are good and dry. There is some moisture starting at the front of the rear axle housing,which I"ve seen other trucks with also. I had it for 3 yrs now and this noise is definately new.Well, I will start with checking the carrier bearings and also the calipers which I heard a couple times now to check. I'ts being looked at saturday for an alignment. I'll have them also check out. I'll keep you posted. Also time for tires. Any good brands to look at. I have Generals now.

[jimmy]

try filling the slip yoke on the drive shaft with greese had similar problems when pulling up to a stop