URGENT! Ring and Pinion - moving on from Motive...who's next? HELP!

[64dartgt]

So I had the 8.75 sure grip (489) totally rebuilt by a very experienced local dif shop. Even spent the extra $130 to upgrade to a fine spline yoke so he could put the "quiter" Motive 3.55 gears in vs. Richmonds.

Long story short.  The Motives suck.  Efforts to quite the loud whine (like when you let off the gas driving a large Uhaul truck) on the glide side only made it louder.    I can barely hear the roar of my freshly built 340.  I didn't pay $1500 to have the rear totally done and then more money to have it installed to listen to this.

The 489 seems to limit options.  The only other vendors I have found are Nitro ($240) and Yukon ($357).

Help me please my Mopar brothers!   

Anyone have any luck with either?  Other suggestions?  I would like to order them this week.

I also have a loud grumbling vibration that starts at 60mph and them becomes louder and cyclical (louder and softer).  I can feel it through the whole car.  Didn't have the problem with the old engine with the old 8.25 rear and rebuilt tranny at all.  When you put it in neutral, it is still present, so I don't think its the engine balance.  The tires are new, and I had them rebalanced and there is no issue with alignment.  I also had the drive shaft tested for balance and it was perfect.

Ideas?  The diff guy said it is definitley the rear end (rebuilt with new green bearings...etc...etc...changed everything but the axles and housings), drive shaft (balanced perfectly) or tranny (just rebuilt and fine with the old engine / rear end).

Any chance the pinion angle could cause something like this if it was off a bit?  I have air shocks but the rear isn't jacked up significantly.  Perhaps I got a bad set of U-joints (they are new).

Thanks a lot guys!   

Bob

[tatrick2me]

The rear end is set up wrong. And it sounds like the pinon nut is loose. In the beginning the wine in cost was a pinion set to shallow.

[heal0048]

I agree that the pinion depth is likely incorrect... I would check your pattern again before you do anything else.  I just dropped in a set of Richmond 4.10s and they are quiet (I spent the time setting up a good pattern). 

[RGA]

Rear end is deffinatly set up wrong, the 489 is a good case, just need to set the backlash and pattern right.

[Charger_Dart]

I setup my 489 with Richmond gears myself, and had some noise afterwards. Took it back apart and rechecked everything. Found I needed an additional .010 shim on the pinion (using a solid spacer). Put it back together and its been nice and quite since. It really surprised me how much of a difference a small adjustment can make.   

[Challenger340]

I've always just stayed with Richmond.......dunno what to say, never had a problem, so never changed

[Budnicks]

I've always just stayed with Richmond.......dunno what to say, never had a problem, so never changed

Me too  , Richmond all the way & their softer stronger Pro Gears on the race cars, "if it ain't broken, you don't have to fix it"...