3.55 gears do I need a complete rebuild kit?

[SRTRICKY]

When installing 3.55's on a viper with about 750 miles on it should I be getting a complete 3.55 rebuild kit or just the ring and pinion? also any difference between the mopar and the unitrax kit? (both are about the same price for ring and pinion alone)
Ricky

 

[Paul Hawker]

Unitrax uses cryo treated parts. They also have designed and provide a hardened and specially grooved pin that is much stronger than stock. I would give them a call and ask them to explain to you the difference. They have a great track record with Vipers. You can also get the same parts from Parts Rack and save some sales taxes depending where you live.

 

[kmg99]

At a minimum, you will definitely need pinion shims, differential shims, a pinion seal and pinion nut. Generally speaking, it is cheaper and quicker just to purchase an entire rebuild kit. You should also replace the ring gear fasteners. The shimming operation is required to assure proper wear pattern between the ring and pinion and the proper backlash. All of the problems attributed to "gear noise" are because of improper set-up at installation.

I would also recommend new pinion bearings and leaving the existing bearings on your old pinion.

I used the Unitrax hardware and kit from Jon B at Parts Rack. It was top notch. I safety wired the ring gear bolts and put a little extra preload on the differential bearings to handle the shock loads. If you plan to do much in the way of hard launches at the strip make sure you put a little extra backlash in the set-up. It will run longer and cooler...at the expense of a very light potential clunk upon torque reversal.

 

[Herc]

Just bought a 2005 and have been reading alot about the 3.55 setup. The Viper
tech here in SLC tells me that after the engine sets in all I will be doing
is burning tires with the 3.55 setup, he says he's done a bunch, and recommends
sticking with the 3.07. Right now I have about 150 mi and while quick, have
to keep it under 4000 rpm, it is not earth shattering. Does this really change
after the engine "sets in" ?

 

[Andrew2KRT10]

I went with the 3.55, best mod I did. I get to use 6th.

AC

 

[DSR207]

".....................................................
Just bought a 2005 and have been reading alot about the 3.55 setup. The Viper
tech here in SLC tells me that after the engine sets in all I will be doing
is burning tires with the 3.55 setup, he says he's done a bunch, and recommends
sticking with the 3.07. Right now I have about 150 mi and while quick, have
to keep it under 4000 rpm, it is not earth shattering. Does this really change
after the engine "sets in" ?
..........................................................

You can't floor it in first as it's now and it will only get worse with the 3.55s. Unless you upgrade your tires and wheels, shocks, and do other mods to beef up the rear end you need to stick with 3.07. Some info about it here
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