LS rear end grind on 2004.5 4x4

[CUMMINZ]

When I am turning sharp to left pulling my 5er... I get a hard vibration in drive train. Factory man and shop teck tells me it is a normal thing for LS rear end especially with larger tires to do this. They tell me LS in 2004. 5 does not have clutches and much room for slip.



Anyone else getting this?

 

[steved]

Umm, no.



This is a torque biasing LS unit. The more torque you put into it (as long as the wheels don't spin) the harder it tries to hold... basically, there are two "shoes" that are being pushed outward that give you your "traction".



I personally have found the tracrite very disappointing and basically not any better than an open differential (especially when compared to say a powerloc in a D70 or the factory D80 tracloc).



I would have it looked at as that is not normal at all. What your mechanic is telling you is true for a clutch style LS... one that HAS preload all the time (like a powerloc or a tracloc, and one that someone forgot to add friction modifier to)... the tracrite only applies force to the clutches as torque is inputted to the rear. It should not EVER chatter and never needs friction modifier.



If you are under warranty, that is something you should have DC check.



steved

 

[CUMMINZ]

DC checked

My first post was clear that I have already had DC check the truck. They say it is normal to chatter. What more can I do?



CUMMINZ

 

[steved]

And like I stated, the tracrite is different than the older Dana LS they are telling you it is acting like... I already went down this road with mine because of its lack of performance.



I also ran 35 inch tires for a while... it made no difference... think about it for a second... how would larger tires affect a differential? That diff doesn't know (or care) if it has 13 inch tires on it or 40s... the tires affect the diff the same way a load will... more stress... so it isn't any different than running stock tires on a loaded truck.



Are you sure you are not rubbing the lower control arm with your tire?? that makes a vibration that feels like it is in the drivetrain... my 315s on factory wheels did this from time to time. Check for a rub mark.



Drivetrain "chatter" is not normal... find another dealer or ask for a regional technician to check it.



good luck,

steved

 

[mberry]

Several people have fixed the chatter by adding friction modifier. We all know it's not supposed to make a difference, but it does in some.



Also, it may be time to change the differential lube. I put Royal Purple 80W-140 in mine and have had zero issues with it. I am going back to the 75W-90 before it gets too much colder here and it's got 23K miles on it anyway. As they say, it's cheap insurance.



Another thought. Could it be your U-joints possibly?

 

[sag2]

This is from STAR since the service manual does not have diagnostic info.



Another test for Trac-Rite is to slowly drive vehicle in an open area and completely turn wheels to one direction and accelerate hard. . The vehicle will experience tire hop or shudder. This is a normal.

 

[CUMMINZ]

rear end chatter

I added AMSOIL gear oil at 15k and just called the AMSOIL home office and they say their gear oil already has a modifier in it. I have still ordered 4oz. of their modifier to add this weekend.



I do have rub when lock to lock to leftt but that is not the issue. I can make the same turn under no power and NO noise. Can keep into the turn under power and get the shutter.



CUMMINZ