Weird noise with 3.55 gears at certain speeds

[jmt5049]

Hey guys,

Just recently had a Unitrax 3.55 installed on my '06. The car has 10k miles on it & was installed at a local shop that has done multiple gear changes on vipers. I used mobile 1 gear fluid in the diff. I broke it is as stated for 500 miles, no romping on it or aggressive driving. While driving I notice that is whines at speeds between 60-80 mph. It occurs only between those speeds, plus or minus it makes no noise at all. Has anyone else ever experienced this? Could it possibly be something wrong with the install or the fluid I am running? Any help would be appreciated.

Thanks guys

 

[JoelW]

Did you use the Mopar additive? Unitrax also suggested I use Royal Purple gear oil ( I am a Mobil 1 fan too) but the additive is a must. During my earlier muscle car days, rearends without the additive would not work right. I would suggest a change of fresh gear oil and use the additive and see if the noise goes away. By the way, mine does make some noise I notice with the top up or the hardtop on but it is right behind your seat so I suspect that is normal but I don't have a whine - except from my wife if I go too fast or drive by a rest stop.

 

[jmt5049]

Any other thoughts?

 

[v10viperbox]

My 3.55 whine's a good bit from 35-55 or so. Then above say 85 or so. But it's not really terrible, the rear end ratio changes the cruising RPM a good and it's deceptive when you try and compare the new drone with the old.

Do you have a different LSD in the back?

 

[FrgMstr]

I was instructed that if I did not break my 3.55s in correctly I would very likely have gear whine.

 

[bluesrt]

loose incorrect tolersnce of ring n pinion

Loose incorrect tolerance of ring n pinion

 

[jmt5049]

^ that's what I am afraid of. It is a factory rear with just the ring and pinon upgrade. I will attempt to change the fluid and use the mopar stuff. At this point I feel the shop that installed it may have made an error after hearing what everyone has said. Will this cause permanent damage to my rear end?

 

[bluesrt]

dont bother wasteing your time changeing the oil and all that stuff, wont help a bit- no it will not harm nothing at all,