How To Disassemble and Rebuild the Rear Differential including Seals, Bearings, and Brakes on a Ford 4000 Tractor Pt. 1

This particular model tractor is a 1962 Ford 4000 tractor 4 cylinder.  I looked down into the differential through the fill hole and saw this:




The pinion bearing on the rear of the pinion shaft had come apart and bent the hold down bracket outward scraping the carrier housing.  Also, both rear outer axle tube seals have leaked grease into the brake shoe drums ruining the drum brakes.  And finally, the rear lift is not working at all.  As there are many repairs to be made, I have tried to focus in on the most important ones and in somewhat the order I tackled each one.

First step, remove the seat assembly.  There is a lever at the front of the seat to lift the seat out of the way and allow access to the two bolts attaching the seat to the housing.  Once those are removed, the seat assembly lifts right off.








Then, to remove the rear lift assembly, first drain the fluid from the housing.  Then, remove the pin holding the draft link to the swivel bracket.  Remove the pins from the left and right rear lift arms.  Remove the bolts attaching the lift cover to the differential housing.  Because there are two sizes of bolts, I prefer to layout the bolts in cardboard in the pattern I removed them.

















Then, jack up the rear of the tractor on the center of the differential housing, and then put jack stands under the rear loader arms – or if there isn’t a loader, then place jack stands under the transmission housing.  This tractor has rear wheel weights, so I removed them first, then the wheel weight bracket, and finally the lug nuts and wheels/tires.








Next, remove the nuts from the front of the drag arms, and the bolts attaching the chains to the bracket around the PTO shaft allowing you to remove arm assemblies on both sides.  Then, remove both bolts/nuts from both fenders and lay aside.










Then, loosen both rear brake adjustments – left rear (back to front) & right rear (front to back) –  then remove both brake drums.  This one is covered in grease, filled with dirt nests, and almost void of brake linings.  Remove the brake adjuster spring, the two hold down springs, the two metal pins with clips, and the remaining springs, then pull off the brake shoes.  The pictures show the right rear then the left rear – there were a few pieces missing from the left rear when I pulled the drum off.



















Next, remove the nuts that attach the outer wheel hubs to the axle tubes.  Then, rotate the foot brake lever so that it slides out of the brake shoe backing plate.  The left side brake lever requires removing the adjusting rod pin to allow the lever to rotate to the desired position.  Then, finish pulling out the axle assembly – same on both sides.  There will be shims between the axle tube/trumpet and the wheel hub.  MAKE sure you mark which side they were on as they affect endplay and will need to be reinstalled on the same side they were removed from when reassembling later. There is a hole cut out of the side of each axle tube that the brake lever bar slides into.

I had to cut off one stud as it began to spin inside the housing not allowing the nut to be removed.











Then, remove the bolts and two nuts that hold the axle tubes to the differential housing along with the brake locking brackets on both sides.  Next,  remove both axle tubes – you may have to tap the back of the end of the axle tube to free up the axle tube.








Bottoms of axle tubes – the left and center picture below is of the left side, and the right is on the right.






Go ahead and remove the carrier bearing race and the outer axle tube seal at this time.  It is easy to use a long pry bar running down the axle tube to get to the back of the carrier bearing race to knock it out, and a seal puller to remove the seal on the small end of the axle tube.







Now, install the new carrier bearing races, and axle tube outer seals making sure the lips of the seals face inward.  Because I didn’t have a driver large enough to fit the carrier bearing race, I laid a piece of square tube steel across the face of the race and then drove it down with a mini sledge hammer – even then I had to set the old race on top of it to finish the job as the race sits slightly below the edge of the axle tube hole.





Once the axle tubes are removed, you can easily see inside the differential housing.  The carrier/ring easily slides out the left side of the housing – it’s a little heavy so you might need a second person.  Once it’s removed, you can take a chisel and hammer, and knock off the rivet heads attaching the rear bearing hold down bracket; tap what’s left of the rivets toward the front and they fall right out.













Hook up an engine hoist to the rear case/housing, unbolt the outer housing bolts attaching it to the transmission, and remove the entire assembly.  You’ll notice the intermediate shaft that slides onto the output shaft of the transmission as well as the front splines of the pinion shaft – it easily slides off as you remove the rear case.  Clean the rear of the transmission housing and remove the gasket.  At this time, it is a good idea to remove the L-pipe that is bolted to the front of the transmission and bottom side of the hydraulic pump in order to clean out the tubes that run through the transmission housing.  Also, there are 2 O-rings on the rear of the transmission housing that seal the tubes as well as 4 O-rings on the top and bottom of the L-pipe:  all of which will need to be replaced.  I use brake cleaner to clean out the hydraulic line tubes and then push a paper towel through each of them with a 3′ rod to clean them out.














Once the rear housing is removed, set it on a the ground (probably use some blocks to help it stay stationary) and begin removing the pinion shaft.  You’ll remove the six 9/16″ bolts from the cone shaped housing which will allow the entire assembly to come out.  The cone comes off first, then you can bend the tangs from the locking washer off of the outer nut and remove it followed by the inner nut, and then flat washer.  Once those are removed, the front pinion bearing slides off the shaft allowing the shaft to fall out the back of the pinion shaft steel housing.  These pinions have 3 bearings – front (slides on pinion shaft but race is pressed into the steel housing), middle (pressed on to the pinion shaft and race is pressed into the steel housing), and the rear (slides over a bushing which is pressed on the rear of the pinion shaft).












The only thing left of the rear pinion bearing was the outer race which simply slides into the cast hole in the housing.





Remove the pinion shaft end bushing and middle bearing by pressing and/or cutting them off – I had to end up cutting off the bushing due to the end of the pinion shaft slightly mushrooming because of the bearing damage (once the bushing was off, a file made quick work of the mushroomed edges).  Also, remove the carrier bearings at this time – I ended up cutting those off also.  After removing the bearings and bushing, press on the new bearings and bushing.
















The flat plate of steel I was using on top of the new carrier bearing race to press on the bearing stopped as it made contact with the carrier, so I added the old race on top to finish the job on both sides.




Then, shift your attention to the wheel bearings.  I tried to “press” them off with no luck and so had to resort to “slamming” them on a steel plate while holding force down on the wheel hubs and brake backing plate to remove the locking collar and wheel bearing.   It was definitely a good back workout but got the job done.









Once the wheel bearing and locking collar were removed, the hub slides right off the axle.  At this point, you can use a punch and hammer to remove the wheel bearing race on the inside and the seal from outside of the wheel hub.





Next, if you prefer, remove the bolt on parts including the PTO shaft from the rear housing in order to clean, prime, paint, and replace gaskets.  Another optional thing to do at this time is clean, prime, and paint removed parts from prior disassembly such as wheels, weights, weight bracket, rear case/housing, parts bolted to the rear case, steps, rear hubs, brake backing plates, brake foot levers, etc.













I used these products for priming and painting.




















Continued in How To Disassemble and Rebuild the Rear Differential including Seals, Bearings, & Brakes on a Ford 4000 Tractor Pt. 2…..