Ok gents I need to know what I'm looking at here. Every time I turn my wheel all the way left and left off the brake to start moving slowly I feel a bad vibration. I had a buddy follow along listening and it is coming from the rear end differential... i know my wheel can fly off so I parked it. I recently changed all fluids 75/90 royal purple. I want to know worse case scenario so I know to open her up or not.. I'm looking at getting layed off so I don't want to open a can of worms with my truck up in the air and not be able to move it . I am mechanically inclined but not with diffs.... thnx in advance fellas.

Do you have a limited slip differential? Reason I ask is since you recently changed oil if you didn't add friction modifier to the oil this will make your clutches chatter and do exactly what you describe, it will not hurt anything but it is annoying but if you do not have a limited slip diff then start by checking u-joints, physically try to move pinion shaft in and out or up and down to see if a pinion bearing has failed usually the input seal will be leaking, jack it up put rear end on jack stands put in neutral rotate driveshaft by hand to feel if you hear any grinding clunking ect, pull plug from diff check oil for metal by dipping your finger in and see what it looks like make sure you listen to outer wheel bearings and brakes while turning the driveshaft. then pull the diff cover and physically look for big chunks of debris. Take pics if possible and post up.

 

If you are not sure if you have a limited slip or not easy way to check is to jack up the rear end and with it in neutral rotate one rear wheel, if it is a limited slip both wheels will turn the same direction, if it is an open differential the wheels will turn opposite of each other.

Or leave it in park while jacked up and if you can not turn one rear wheel you have a limited slip and if you can easily turn the wheel and the other turns opposite you have an open diff.

I don't have limited slip I know that. I will jack it up here in next couple of days and start moving stuff around. Thnx for ur input I will check back in.

Oh.. Wait scratch that. It might just be limited slip. Just reread the last part.

You can also check for metal in the fluid by sticking a 'magnet on a stick' in the fill hole.

Oh.. Wait scratch that. It might just be limited slip. Just reread the last part.

 

lol.............I like to reread my own posts and then edit to add a lot of things after I post, sometimes I do it several times just to see if anyone is paying attention.

Mopar friction modifier from the dealer, at least one bottle. May need to or three. Start with one and see if your noise goes away

I will get on it as soon as I can.... but I will note that it not just a noise it vibrates with its noise to go with it ...  ...  but I must know, could there be a lubrication issue causing that much vibration...  i mean, I would think that "royal purple " would be plenty ...  unless of course my diff was on its way out prior to servicing 

lol................No matter what lube you run you need limited slip additive to make the clutch discs happy. You can not believe how hard they chatter in corners without it. It will do just exactly what you describe and then some in some cases depending on the oil. I am an Amsoil dealer and have always run and built and custom built my own clutch type limited slip units and I have tried most of the different types and weights of Amsoils gear lubes and clutch type units like the regular old 80-w90 the best, the best severe gear oils were the worst as far as clutch chatter went. I called and talked to both eaton and Amsoil and they said that the clutch disc manufacturers have not kept up with the synthetic oil market and still make the same old clutches and both recommended to stay with the regular grades of synthetic oils, This is why factory limited slip units are so weak but better than an open diff, if they stacked the clutches too tight then they get too many warranty claims from disc chatter and related drivability issues from people who don't know any better.

When my differential went south, the driveshaft was hopping in and out of the housing and shaking and grinding. Certainly a lot more fierce than a little chatter going around a corner.

Add the modifier then do some slow figure 8's in a parking lot.  You should feel it clear up in a few minutes. Check your glove box door for the limited slip tag. 

I've talked with Sadler Power Train in town, and they said that it's common on these doges for limited slip to go out and make noise. No matter how much stuff you add, it needs to be serviced. Ether clutches need to be reshimmed or new clutches put in. Last time I checked if I brought my center section in it would be around $150 for new clutch pack installed.

I've talked with Sadler Power Train in town, and they said that it's common on these doges for limited slip to go out and make noise. No matter how much stuff you add, it needs to be serviced. Ether clutches need to be reshimmed or new clutches put in. Last time I checked if I brought my center section in it would be around $150 for new clutch pack installed.

Having worked in a gear shop for 4 years and doing it for over 20 years on all types of other equipment and doing literally hundreds of them I have to call BS on that shops general info on the Dodge LS units "Going out". The same unit has been used in other rigs with dana axles  the last 20+ years, it hasn't changed. There are 2 types of dana eaton clutch type LS units, one is a trac lock and one is a power lock the power lock has a V shape on one side on the cross shaft and in the case and uses a torsion action to actually put more pressure on the discs if it tries to slip and is a stronger better unit and heavier case than the trac lock which is the most common and has a round cross shaft for the side gears. I hve seen where the light pressure of the trac lock stack the OEMs require to prevent chatter can still one wheel in some situations and if done regularly will glaze the clutch discs and cause little to no LS action and can chatter after the plates and discs warp but it is rare other than that there is little in them to "Go out". An eaton friction Disc kit is about 40 bucks last time I bought one and it takes about half hour to install if the carrier is on a bench already.

 

Power lock picture to see what the cross shaft looks like.

 

Regular trac lock will look similar to this, notice the cross shaft and case differences.

Having worked in a gear shop for 4 years and doing it for over 20 years on all types of other equipment and doing literally hundreds of them I have to call BS on that shops general info on the Dodge LS units "Going out". The same unit has been used in other rigs with dana axles the last 20+ years, it hasn't changed. There are 2 types of dana eaton clutch type LS units, one is a trac lock and one is a power lock the power lock has a V shape on one side on the cross shaft and in the case and uses a torsion action to actually put more pressure on the discs if it tries to slip and is a stronger better unit and heavier case than the trac lock which is the most common and has a round cross shaft for the side gears. I hve seen where the light pressure of the trac lock stack the OEMs require to prevent chatter can still one wheel in some situations and if done regularly will glaze the clutch discs and cause little to no LS action and can chatter after the plates and discs warp but it is rare other than that there is little in them to "Go out". An eaton friction Disc kit is about 40 bucks last time I bought one and it takes about half hour to install if the carrier is on a bench already.

Power lock picture to see what the cross shaft looks like.

Regular trac lock will look similar to this, notice the cross shaft and case differences.

I think they were talking about trac lock and said that they only last so long and then need to be re shimmied or replaced or it can Granade if not taken care on time. You might be right though I'm only saying what I heard.

Speaking of  LS  additives,    Mopar's      used to be   whale  oil/blubber  ..    At least up  into the late 70's!

Well I'm amazed at how much difference a bottle of friction modifier made.  Threw a bottle in and semis to be 80% better.  Maybe I throw in another bottle.   Thanks alot for the help guys.  I will look into getting a service done on it.    At the same time I did this I installed a DTT noise filter for my Trans gear searching issue....  another 80% difference.  Night and day.  Also fuel mileage noticeably  up.   Thnx for all ur help fellas.  I will try update that other post. 

At the same time I did this I installed a DTT noise filter for my Trans gear searching issue....  another 80% difference.  Night and day.  Also fuel mileage noticeably  up.

 

I highly suggest you pull that noise filter out and replace the alternator. If you leave the noise filter in you will most likely destroy the ECM, PCM and VP44 next.

Daaaamn.... i knew was too good to be true. Moparman, thnx for the advice. I wanted to replace my alternator anyways..

More here...

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/28-transmission-systems/260-torque-converter-lock-unlock-issues

 

And here

http://forum.mopar1973man.com/index.php?/topic/4988-torque-converter-lock-unlock-issues/