1971 Chevy Suburban - Project SuperBurb - Part VI

Be careful when removing the idler gear, as its front bearing has shims underneath it. The same shims need to be reused upon reassembly, so make sure not to lose them. You'll need them all.

Now it was time to open up the NP205 rebuild kit from National Drivetrain. It included all the seals and gaskets we needed, along with high-quality Timken bearings to replace our tired ones.

The next step was to install new races and bearings from the rebuild kit into the idler gear.

There are also bearings underneath the gear on the rear output shaft that have to be replaced. To get to them, a snap-ring, along with a washer, must be removed. This tiny pin must also come out-be careful not to lose it. Once that is out, the gear can be slid off the shaft, but make sure to note how everything came off the shaft, as the parts need to be reassembled in the correct order. Also, be careful as the needle bearings will fall out when removing the gear, but it is OK since they are being replaced.

With the rear output shaft stripped, the bearings can be replaced with the new ones supplied in the rebuild kit from National Drivetrain. The trick is to grease the shaft so that the bearings will stick to it. Once the bearings are in place, the gear, along with its washers and snap-rings, can go back into place. Also make sure to remember to install the tiny pin.

There are also bearings on the inside of the front of the rear output shaft that need to be replaced. These are difficult because they are down in the shaft. We used plenty of grease, a magnet and lots of patience to get ours into place. After they are in place, the ring and washer must also be put back into position.

The front output shaft is similar to the rear, as there are bearings also under the gear that need to be replaced. To remove the gear, remove the snap-ring and washer first. The bearings can then be replaced by greasing the shaft and sticking the bearings on just as we did with the rear output shaft.

After thoroughly cleaning the case and all of the parts, it was time to put the idler gear assembly back in. It takes a bit of patience, as you have to support the gear, hold the bearing and make sure the shims don't fall out while you slide the shaft into position. Once the shaft is in, the nut on the front of the shaft located on the front of the transfer case can be tightened. After that is accomplished there should be no front-to-rear play in the idler-gear assembly. The end of our shaft (seen here) was below flush with the case after being slid in all the way. If it is not, there may be some play in the gear assembly, so make sure the shaft is all the way in.

Next, the new seals for the shift rods can be put into place and then the shift rods themselves can slide into position. Make sure the detents on the rods are pointed toward the center of the case as they go in.

As the shift rods are sliding into position, the smaller shift shafts (seen here) on the inside of the transfer case also need to be installed. Remember to slide one shift shaft out and the other in a bit to get the shift rod to clear. Then repeat the process with the other rod.

As the shift rods are being installed, the shift forks on both rods should be put on the rods. The hole on the back of each shift fork needs to line up with the hole on the rod and then the roll pins can be reinstalled to attach the shift fork with the shift rod. Also, remember to install the plugs over these pins, otherwise the case will leak oil. The two ball bearings that were removed before can also be installed at this time in the holes on the top of the transfer case. Make sure they drop into the detents on the shift rods, and then install their retainer bolts with their springs.

Now the front output shaft and its gears can be put into position. Make sure that the shift collar lines up with the shift fork so that the case will shift. Then install a new bearing on the front of the shaft, along with a new bearing in the rear cover. With the bearings in place, the rear cover can be put on.

The main input gear along with its smaller shaft can now be installed. Make sure that the shift collar lines up with the shift fork, as seen here.

Next, the rear output shaft can slide onto the main input gear. The front of the rear output shaft has needle bearings in it, so care must be taken so that these do not fall out, or come out of position, while putting the shaft into place.

With the rear output shaft and gears in place, the rear output bearing retainer assembly can go back on. Then the speedo-gear assembly can go back in. Make sure that its gears mesh correctly before installing a new bearing from the rebuild kit. After that, the rear output shaft seal retainer with a new seal can go back on.