Clunk/shudder from Rear when starting turning from stopped

[James Vellenga]

I have been fixing various things on my 2005 Ram. After doing some front-end work, the rear u-joint which was probably going for a while started producing a lot of vibrations at highway speeds. I replace the u-joints, and the last thing I have left is a shudder or clunkiness when starting from a stopped position while turning. It doesn't happen when going straight or when turning while moving only from a stop or very near complete stop. My guess is it is the locking rear diff, although when I did the rear u-joint it was the first one I ever did, and I did struggle with it far more than the front one on the driveshaft. I am wondering about people's thoughts on possible causes.

My plan is to check the driveshaft to make sure the u-joints have no play and are moving freely as that will at least set my mind at ease about them. If the rear one which I did first is binding at all, I will deal with that. If everything looks and feels good. I will drain the diff and replace the fluid and friction modifier using the one from Mopar since when I did it when I purchase the truck two years back I didn't use the Mopar friction modified, and reading around today people say that may be an issue. I would like to figure it out before heading out camping in a few weeks.

 

[kdoublep]

I would start with the fluid and modifier. I'm not sure how truck ran without it unless you're saying you used a different manufacturer's modifier when you first changed it?

 

[nlambert182]

My 2012 2500, 2016 3500, and my current 2018 1500 all have a similar clunk when taking off from a stop. I've never found anything wrong with them and have just assumed that it is normal operation for the Rams. It's annoying, but it has never caused me any problems. I would like to know what it is, though.

 

[Daw14]

Does your truck have a carrier bearing ? If so ,may be worth a look over .

 

[James Vellenga]

I would start with the fluid and modifier. I'm not sure how truck ran without it unless you're saying you used a different manufacturer's modifier when you first changed it?

Yes, I used a different manufacturers friction modifier. My work schedule is such that getting into the Chrysler dealership when they are open basically means I would need to take time off work. Carquest had another friction modifier in stock and are open later than my end of work time, so I got it there.

 

[James Vellenga]

Does your truck have a carrier bearing ? If so ,may be worth a look over .

I don't actually know. I will have to look into that.

 

[FabricGATOR]

I just bought my 4oz Mopar Limited Slip Additive p/n 4318060AD from Summit Racing online

 

[CoachK23]

Have you opened up your differential? Mine was doing the same thing. Differential was shot, I learned this....DO NOT OVER LOAD! I believe doing that was the cause.