Nissan recommends 90W GL-4 gear oil for this transmission. GL-5 gear oils which are required in hypoid differentials are not used in most synchromesh transmissions. The chemicals used in the GL-5 oil that provides the extreme pressure protection can be corrosive to synchronizers, which are commonly made of brass or bronze. Typically, the use of a GL-5 lubricant in a synchromesh transmission will shorten the synchronizer life by one half.
Clutch
The CenterForce II clutch provides 60% more holding capacity over a standard OE clutch. The weights are designed to add centrifugal assist to the clutch spring and increase the clamping force as engine speed is increased.
Check the clutch pedal height and free play for proper adjustment. Break-in the new clutch before applying full engine power to properly seat the clutch disk to pressure plate and flywheel.
Driveshaft
Regardless of how the suspension is lifted, driveline angles will change and with a 2-piece rear driveshaft, the lifespan of the center (carrier) bearing will drastically shorten. If the angles are not corrected, vibration and increased wear to the bearing is eminent. To alleviate this, swap it out for a one-piece driveshaft.
Front Axles
I kept popping the inner CV joints using the wrong differential brackets from Trail Master. The R180A requires Trail Master kit #8040 to properly align the front axles with the 4" suspension lift.
Rebuilding axles is affordable and easy if using the right tools, but it is a timely and messy chore. For me, the cost of remanufactured axles far outweighs the time and mess it takes rebuilding them.
When the OE hubs started slipping, I picked up a set of SuperWinch manual locking hubs. These hubs need only 1/4-turn to engage or disengage, unlike others that need a 355 degree turn. Manual-locking hubs have better control over being locked or unlocked than automatic-locking hubs. With automatic-locking hubs, the vehicle will need to reverse 3.5 to 7 feet in order for the hubs to disengage.
Brakes
The brake calipers and rotors needed serious attention after 160,000 miles. The calipers could have been rebuilt and the rotors cut, but I like to save time and spend money so I picked up new rotors and loaded calipers from the local parts store.
There are two types of traction control differentials for these trucks: Locking and Limited Slip. Nissan has an exceptional limited slip differential (LSD) equipped from the factory. Tractech offers a Detroit automatic locker that keeps both drive wheels locked together (except when turning) to deliver maximum traction to the ground. This locking differential made a significant improvement off road over the conventional "open" differential. ARB offers a selectable air locking differential that has the advantages of being open or locked as needed.
