Your vehicle's Shop Manual Section 4 - While this is very informative and recommended reading, none of us have all of the specialty tools they recommend and most of them are unnecessary.

Be sure to watch the above Slideshow! It is the very same material as used to create the Booklet Rear Axle Overhaul and has a lot of really good pictures and explanations that will help you.

Patrick's Installation Instruction (very good if you can get it) - Patrick's instruction is almost like this one in that he does not remove the entire torque tube system from the truck but his article talks about the front bushings and removal of the connection at the transmission. It's a good read and very instructional. As far as I know, it is not available on the Internet.

Chris Sweet's Installation Instruction - This is very good especially if you are taking the entire truck apart for restoration. Chris has a good way of explaining things.

I am always looking for bargains, but I also want unparalleled quality when it comes to something that is this critical to the Driveline. I have found all the usual vendors to have good quality Gear Sets. For you 47-55 drivers, the new gear set you want has a 3.55:1 Gear Ratio. I ordered my new Gear Set from a company out of Tucson, Arizona called Mother Truckers. Joe has a large quantity of these gear sets and sells them about $100 cheaper than the closest competitor. I found the gear set was brand new, in new packaging, and secured very well for shipping. I would not hesitate to purchase from him again. I also found the quality to be very good. You can get ahold of them via email at mothertruckeraz@aol.com.

Besides the actual Gear Set, there will be select Bearings, Seals, Gaskets, etc. that you may need. If you have a local BRC Bearing, or Murdoch Supply, or any company that specializes in Bearings and Seals, you can get them cheaper by eliminating the middle man. All you need is the part number which is supplied here. My estimate on total cost is about $600 for most installations TOTAL including the Gear Set. If there is nothing wrong with your Bearings and Seals, maybe much less.

What sets you apart from the mechanic down the street who charges $80 an hour is, you have to drive this truck when you are finished. So, think HARD about your skill set. The Mechanic down the street is experienced and knows what to look for. If you decide to do it yourself, be sure to err on the safe side. For example, if there are any pits or bumps on the Axles, it may be necessary to install a Speedi-Sleeve (for seal contact area only). Take lots of pictures and really have your thinking Cap on when doing this!

Remove the bottom three bolts on the Differential Cover to drain the Gear Lube. Once it stops dripping, remove the other 7 bolts and lock washers. Clean them up and place them to the side for later re-installation. Clean up the Cover, Drain Plug, Brake Line Clip, and the ten 3/8" (24) by 13/16" and replace the 3/8" lockwashers.

Push the Axles inward and you may hear a 'tink' which is the sound of the C-Clips falling out of the axles inside the differential. Push in both axles and then with a telescoping magnet tool, probe around for these clips as shown. Pull out the Axles carefully being sure to keep the shafts centered so as not to disturb the very delicate seal at the backing plate. We haven't inspected any of this yet and there is some inspection to do! In the case of this particular truck, the Axle Bearings and Seals were in very good shape so I opted to not replace them. It is VERY possible that you will not be so lucky. So, let's discuss what to do.

Axle Inspection: First lets take a look at the Axle shafts. Clean up the smooth area where the bearings and seals ride on the Axle. In good lighting, check for pits, or ridges that could cause seal leakage or bearing damage. If you feel there are ridges and/or pits that could cause seals to not seal properly, you can get a Stainless Steel Speedi-Sleeve that goes over that area and makes everything smooth again. If there is damage in the Bearing area, you should replace the Axle. These sleeves are not cheap (about $60 each) and they are also not easy to install. The trick is to put the axles in the Freezer and get them very cold, then use a long pipe that just barely slips over that Axle area to carefully pound the sleeve into place. The option I choose, since my wife does not take kindly to my using her precious freezer for Axles is to take it to a good mechanic that does this routinely and just pay to have them installed.

Axle Housing Inspection: Look around the hole for wetness that could be caused by a leaky seal. If the area looks like gear lube has been getting past the seal, replace the seal. To get the old seal out, since it is not reuseable, I just pull it out with pliers or jamb a screwdriver into it and bend it out being careful to not disturb the bearings. With the seal out (or not), let's look at the bearings. Does the bearing race look serviceable? How about each bearing? Does everything spin freely? If there is any doubt, remove the old bearing with a 3-Jaw Slide Hammer. Clean the area where the bearings and seals go thoroughly, then spray some Lithium Grease in the area to make the new bearings and seals go in smoother. Clean the Axles and ensure the drain hole is clear of dirt and grime. Check the threads on the Studs for serviceability and replace them as needed. Brake Cleaner Spray is a good choice for cleaning these parts.

The glory of this procedure is not having to remove anything at the transmission end. But to do this, we need to pry the pressed in Pinion Gear shaft along with the driveshaft out at the same time. The splined drive shaft will just nicely back out of its splines and everything will come out in once piece. We start by removing the three Set Screws surrounding the torque tube just forward of the differential assembly. These three bolts on the outside of the casing have 1/2" wrench head and a 3/4" lock nut. Loosen the lock nut first, then remove the bolt with the lock nut on it completely. Clean them up and have them ready to reinstall later.

Slide the Assembly clear out and place on a good work bench. Now is when the fun begins! First order of business is to separate the drive shaft from the pinion gear shaft. You will notice at the weld on the Pinion end of the Driveshaft (about 1/4" in to the drive shaft) is a lock pin. Both ends are peened so the pin does not come out. This pin is not salvageable and will have to be replaced. To make it easier, grind off one side of the peened area, then drill a 1/4 Inch hole on each side about 3/8" deep or so just to relieve the pressure, then with a flat punch, pound out the pin. To make a new pin, get some 5/16" rod, cut it a little longer than needed so you can peen the ends. With the pin removed, the splined pinion shaft assembly will pull right out. (Do NOT reinstall the pin yet! We need to do some adjustments to just the Pinion Shaft!)

THE hard part in this part of the procedure is getting the Pinion Nut (8) off. It is not only torqued to 240 foot pounds, but it also has been smashed near the bottom where that half-moon cutout in the threads on the shaft is located. They did not want this thing moving! First find yourself a 5/16" by about 3 inch hardened bolt to stick into the pin location so the splines will not turn in the vise. The vise does minimal or no damage to the splines if they are secured properly when clamping, however, if you plan on re-using this 4:11 Gear Set, a very good way to protect the splines is to find yourself a used U-Joint Yoke and put the splined end in the Yoke before putting it in the Vise.

I will never be using or selling a 4:11 pinion gear so I am not overly concerned for the shaft. The nut is another issue. Look over the nut carefully. You will need to pry the 'damaged' punched down part out so it is not working against you. I used a screwdriver that was just the right size for the slot to start bending it back, then slid a small tapered punch under it to finish pulling it up. In my case, this nut had two indentions, so I had a little more work to do. I then used a 36" by 1-1/2" Galv Cheater Pipe on the end of my largest Crescent Wrench. To be honest, I tried it without the Cheater banging on the Crescent with a large Hammer and got absolutely nowhere. I feel the Cheater Bar was the thing that solved the problem. With the Nut out, clean and debur it thoroughly.

Next we need to remove the (6) Front Pinion Bearing. Do not get mixed up with terminology, the front means the front of the driveshaft assembly, so we are first working on the thick (front) Bearing. This has to be pressed out. There is no better tool for this than the Shop Press. Especially if you are interested in preserving the Bearing. In this case there is nothing wrong with the Bearing, so the plan is to reuse it. With the Shop Press set up properly having the two pressure plates situated so as to balance the pressure, we just push it out. A good idea is to mark which side of the bearing faces where. You want the bearing to be oriented the way it was on the other shaft. If there is any doubt about the proper orientation, refer to film strip number 37 above.

Next the Pinion Retainer (5) just comes right off. Be sure to mark which side goes towards the front pinion bearing. This is a specially tapered item so it matters which side goes where.

Next to be removed from the old Pinion Shaft is the rear bearing shield (4). This orientation matters too. Be sure to get it so it shields the bearing. Pay careful attention to the pictures and you should be fine. Next comes the Retainer Ring (3) for the Rear Bearing. (This is the Bearing closest to the Pinion Gear). I just used a few small screwdrivers to pry the ring out and down where it can be easily slipped off. With the Retainer Ring out, the Rear Pinion Bearing (2) slips right out. Check for serviceability. Set all parts aside after cleaning.

With everything thoroughly cleaned and all parts found to be serviceable, it's time to re-assemble then a test re-install of the Pinion Shaft Assembly. At issue is the Pinion Gear Shims and if we have the right amount needed for the ring gear to travel in the center of the gear set. This is an essential step to ensure proper alignment. Let's start by putting together the new Pinion Shaft.

Use some Spray Lithium Grease, or Gear Lube, or something slick and get the shaft good and covered. Start by sliding the Rear Pinion Bearing into place in the proper orientation right up against the Pinion Gear. Put the Retainer Ring back into place. I found it easiest to use two Vise Grips with sharp edges and pull them apart so the ring expands enough to go over the groove. Do not apply excessive pressure to the ring, just what you need. Next slide the Bearing Shield in the correct orientation over the Retainer Ring and up against the Rear Bearing. Next comes the Pinion Retainer and its very important you put it on the way it was oriented on the old one in order to get the assembly back in. Finally we put the Front Bearing into place. This is pressed on the shaft. The shop press is already set up for this. Just turn everything upside down and you are set up to press the new bearing back on. Be sure to put equal pressure on the center and outside of the bearing so as not to destroy the bearing. Lastly, with everything in place, put the Pinion Nut back on.

Remember, the Pinion Nut has to be cinched down to 240 foot pounds! That wasn't even good enough for them, they also have you taking a punch and bending the bottom of the nut into that half-moon shaped indention. You want to do this because this is something they were apparently concerned about! I wouldn't knock yourself out to get to exactly 240 foot pounds, but the nut needs to be good and tight before you Peen it into place. With the Pinion Shaft put back together properly, we will put the shims on the back of the thick (Forward) Bearing and get ready for the Test Install. Do NOT put the long Drive Shaft back on yet.

Important Tip: The Pinion Retainer (that ring that slops around on the shaft) is going to give you lot of trouble when trying to get the assembly back in. Problem is, gravity and some luck in 'bouncing' it into place is how this is normally done. I prefer an easier method because it has been known to take about 10 times of replacing shim stock to get just the right pattern on your ring gear before getting this right.

In/OUT/In/OUT ad nauseum and I can't imagine having the patience for that, so... With some Super Glue, coat the edge of the retainer that mates up to the Front Bearing (the thick one) and glue the ring to the bearing. You will need to very thoroughly clean the surfaces for them to stick together. Add a little clamping force and come back in 10 minutes to try it. Do not get glue into the bearings, just to the outside. Be careful in applying this.

With the Pinion Shaft equipped with all of its parts, let's install it in the Truck first without the driveshaft. Now is when you see if your Super Glue Plan worked out or not. Before attempting to install the Pinion Shaft, be sure everything you can reach is very clean inside the hole. I like to spray Lithium Grease in there just to be sure everything is slicked up good beforehand. You can use Gear Lube for this too.

With everything assembled on the bench, let's get these new parts in the Truck. We will add a .010 shim to our Shim Pack to start. This is because Dave tells me that is a good starting point to minimize taking the Pinion in and out. Put a little grease on the shims to hold them together and to the back of the Front Bearing. Put some fresh gear oil on all of the surfaces on the inside of the cavity so things are pre-lubed, then slide the assembly into place. If luck is with you, the assembly should go all the way in without much effort.

To test to see if you got it right, shine a flashlight into each of the three set screw holes on the outside of the differential. You should see the inside edge of the Retainer Ring. The best way to proceed from here is to drop a very small screwdriver into the top two retainer holes from the outside. This is to keep that retaining ring from moving forward. THEN, using your fancy new J-4050 Pinion Gap Tool, slide the forked tool behind the Pinion Gear and be sure the Rear Bearing that is up against it, is spread away from the gear by the width of the Tool. With the tool in, install the bottom set screw first, then the top two very loosely. This is when you remove the J-4050 Tool, then tighten the 3 set screws to 30 foot pounds and lock them in place with the locknuts. Remember, you are doing all of this without the main driveshaft in place just so that we can measure and test the Backlash and Pinion Depth for accuracy before installing the Driveshaft!

With no binding and the Carrier Assembly smoothly rotating, with the lock washers not smashed at all, loosen just a bit more and then try to rotate the left bearing adjuster. Without a special tool available, I use a large flat screwdriver and a hammer strategically placed to move the assembly. Tap around this assembly to ensure it moves as you would expect. You want both sides to move freely so you can adjust it correctly.

Loosen the right side adjuster enough so that it does not interfere with the left sides ability to push up against the pinion gear. Tighten the left side adjuster until it gets relatively tight, then back it off a few quarter turns and check for backlash. Backlash is the term they use to describe the dead space where there is no movement of the secondary gear when you move the primary one. Since the number is so small, we use a Dial Indicator for this. We need about .005 to .007 of travel from front to back before engagement. With the Pinion Gear shaped the way it is, you get more backlash as you move it further to the left and less moving it to the right. So to get less, be sure the right side is loose enough to let you move the assembly to the right, and then turn the left adjuster. More would be loosening the left adjuster and tightening the right. This is a pretty critical adjustment, so be sure you can easily feel the slop they call backlash.

With the wear pattern ironed out, it is time to take it all apart once again so we can install the driveshaft. Take a file and run it over the splines at the front of the driveshaft to eliminate any burrs. Clean it real good and then we can turn our attention to the 5/16" pin that holds the Pinion Gear Assembly to the Driveshaft. This goes together really easy. Be sure to line the two holes for the pin up and then push the Pinion Assembly into the Driveshaft and line up the holes. I used a 5/16" Pin Punch for this. Cut yourself a piece of 5/16" steel dowel about 1/2" longer than needed to go through and hammer it in place. Place the joint on top of the vise or anvil so when you hammer it down, it creates a mushroom effect so it cannot go through the hole on one side, then turn it over and do the same on the other. See Slide 39 in the filmstrip above. If you have to cut a little more off, do so to get it just right. Peen the other end so that both sides cannot go through. With it tight and secured, that is all you need to do. There is no pressure on this pin so it is only there to keep front to back movement in check.

There are no pictures in this section because this is just a reversal of the removal. With a clean driveshaft and everything installed on the Pinion Assembly and superglued correctly, time to get under the truck and push the entire assembly into position. I installed the shims first with a little grease on them to hold them in place inside the back of the hole, then carefully (like installing a camshaft) slide the driveshaft up into place. There will be some resistance getting it through the spline at the transmission end, but nothing a hammer handle cannot persuade into position. Before driving this assembly all the way in, install your J-4050 Fork Took in between the Pinion Gear and Rear Bearing. Doing it now will be much easier. Finish driving it home then check the 3 set screw holes to make sure the Superglue held and the Retainer Ring is forward of the setscrew holes. If it is, stick a small screwdriver in one of the top holes just in case, then remove your J-4050 Fork Tool and install the 3 set screws. Torque them down to 30 foot pounds as before. This sets the Pinion Assembly and Driveshaft in the correct position. If it rotates freely (in neutral) then you probably did everything right.

All four of the spider gears are interchangeable and I like to swap positions to get a more even wear of the components. Put what was left on the right side and put what was up on the down side. These gears slide into place easily but do not smash your fingers. With the Carrier turned so you can see everything, just slide them into place. With the two left and right gears in their slots, install the Axles. Always hold something like this the same way you would a camshaft to avoid putting too much pressure on your new seals. Once they are slid all the way in, put a C-clip in each side and push the Axle out to keep the C-Clip in place. With the Axles secured, install the other two spider gears. The two free gears will need to be exactly across from each other for the Axle retaining block to go in. With the gears installed across from each other, put the Axle Retaining Block in place and put the large Pin through the hole. One end of that Pin has a locking hole that mates with the Locking Bolt so be sure to install it the right way. Once the Pin is aligned with the hole, Bolt in the Pin Locking Bolt and tighten securely. Rotate both axles to see that everything turns freely. Also rotate the Carrier (vehicle in neutral) to see that everything turns as expected.

The final check before buttoning up the Differential is to check the Carrier Ring Gear for Run-out. Run-out is basically how TRUE does the gear run? If there has never been any catastrophic damage to the Differential and you installed the Ring Gear properly, this check will pass. Install your Dial Gauge as shown to see if the needle moves when rotating the gear. You are checking for wobbling of the Gear. There should be no more than .003 difference anywhere.