How to: Replace your rear axle assembly | Ford Explorer Forums - Serious Explorations

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How to: Replace your rear axle assembly

my pos mounty

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06 F-350
I saw this thread and thought I would go ahead and post this. I wrote this a couple of months ago, but I lost the pics I took along the way because the memory card in my camera died a horrible death.

This is how I did this. This is NOT the only way of doing it. There will be many differing opinions on what to do.

First a disclaimer:
I am not a mechanic, I do not play one online.
I used all the proper safety equipment that I felt was necessary. I am not disclosing what I used in its entirety and can not be held responsible for your actions if you choose to disregard common sense or if you fail to protect yourself. Your safety is in your hands. Working on vehicles can cause serious bodily harm, including death.
I will assume that you know how to protect yourself.
-----------------------------------------------------------------------------------------------------------
As a side note: I do not have the "air ride" suspension. If you do, there will be a few things you will have to do differently.

Ensure you get the same gear ratio that exists in your truck now. It is essential that the gear ratios match front and rear.
If you do not know what your ratio is, there is a sticker in the drivers door jamb that has a code on it that will look like this:


picture.php

http://www.explorerforum.com/forums/picture.php?albumid=294&pictureid=3739

Circled in red is what your looking for. The codes for ratio and open or limited slip diff are:

Door Code - open or limited slip - ratio
41........….…… Open 8.8"…....….... 3.27
42..…......……. Open 8.8".….…...... 4.10
43..……......…. Open 8.8"…..…...... 3.08
44..………....... Open 8.8"….…....... 3.73
45..…..…....…. Open 8.8".….…...... 3.55
46..……......…. Open 8.8".……....... 3.73
D1..……......…. L/S 8.8".…...…...... 3.27
D2...…......…… L/S 8.8".…...…...... 4.10
D4...….....……. L/S 8.8".…...…...... 3.73
D5..……......…. L/S 8.8".……......... 3.55

Forgive me for not keeping a running inventory of the tools I used, but If you are considering doing this job and have a good selection of wrenches (SAE and metric) as well as sockets (SAE and metric), breaker bars, a BFH, rubber mallet, seal remover, seal driver (pro grade or “hillbilly” grade doesn’t matter as long as it works), screwdrivers, brake tubing bender and a good selection of pliers, you should be all set.
You will need a slide hammer to remove the axle bearings if you decide to replace them, more on that later.

Before you start a shopping list:

Rotors (maybe)
Brake pads (maybe)
Synthetic diff oil- 3 qts.
Friction modifier (if you have the limited slip diff)
New axle seals and axle bearings (maybe on the bearings, your decision but a really good idea)
RTV sealant
Look at your rear shocks..replacements?
New shock mounting bolts (you might need these, I did)
U-joints for both positions on rear driveshaft (again, not vital, but a really good idea)
Brass junction block and Teflon tape as outlined below (not vital, just another good idea)
I forget what length brake line is needed to cross over the housing, measure this before you go to buy one
Tubing bender
Tubing cutter
Brake fluid
In all likelihood, you will need new parking brake shoes, they tend to fall apart
New cross-pin keeper bolt (the small bolt that holds the cross-pin that holds the spider gears in place, notorious for breaking, never re-use it)
4 new U-bolts (I am from the school where you never re-use U-bolts on leaf springs, some people will disagree)
Parking brake hardware kit (new springs, keepers and star wheel adjuster)
Brake-kleen (I used about 4 cans)
Crap-load of rags
Catch pan for old oil
Maybe even a rattle can of paint to dress up your "new-to-you" axle assembly and/or diff cover

Now, Let’s get busy:
Before doing anything, remove the fill plug on your “new to you” axle housing. It just makes sense to do this now so that you can address any problems with the plug before you need the housing. Sometimes the plugs are stuck and if you can not get it out, you will need to find a way to refill your differential.

Jack up the truck, place jack stands under the leaf spring to frame connection under the rear doors.
Remove tires.
Place a catch pan under the diff cover, loosen the bolts on the diff cover, and tap a screwdriver between the diff cover and the mating surface. Allow the differential to drain.
Remove rear shocks.
Remove the rear sway bar from the axle housing, and sway bar links from rear sway bar.
Remove the "third shock" if so equipped
Remove the “anti-wrap” bars if you have the V8 model
Remove rear driveshaft (make a reference mark on the driveshaft yoke to the transfercase flange to ensure proper orientation upon re-install))
Unplug the ABS sensor
Remove brake calipers; hang them by tie-wire, not by the rubber hose
Remove the bolt holding the brake junction block on both sides of the truck (the block between the hard brakeline and rubber hose)
Remove the rotors. You might have to back off the parking brake adjustments, a very similar setup as the drum brakes of the past. Even then sometimes you will need a BFH and beat the rotors off the axles.
Remove the parking brake shoes and hardware.
Loosen the hard brake line on the drivers side CAREFULLY and remove it from the block.
I got a Brass junction block at Lowes beforehand that had the same threads as the brake line, a bolt that would thread into the junction block and some Teflon tape. Wrap the Teflon tape around the bolt; thread the bolt into one end of the junction block.
Thread the hardline into the junction block, finger tight should do it. (this will stop the brake fluid from draining out of your system)
Go over to the passenger side, disconnect the brake caliper rubber hose from cross-over brake line.
The diff should be drained by now, so take the cover off all the way.
There will still be a good puddle of diff fluid in there, clean it out (easier disposal later if its clean inside)
I am going to guess that you will need to swap over your backing plates/dustsheilds because if you’re getting a replacement from the junkyard, they usually get hammered up by the yard guys dragging the assembly. If you are one of the few fortunate ones and the backer plates are good, skip down past removing the axles and the aforementioned backer plates from your “old” axle assembly.
CAREFULLY remove the cross-pin keeper bolt. Pic of bolt:

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3308

Remove the cross-pin.

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3123

Push one axle in far enough so that you can remove the “C” clip in the differential. Pic of what a C-clip looks like in the differential

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3779

Remove the C-clip and then slide the axle out of the housing, repeat for the other side.
Unbolt the backing plates from the existing axle housing, 4 bolts per side. Set them aside. The parking brake pawl will slip out. I studied (and photographed and lost the pictures) how this all fit in the backing plate before I disassembled it, you might want to do that as well so you know how it all goes back together. (just don't lose the pictures obviously)
Loosen the 4 U-bolts that hold the housing to the leaf springs and remove them
Remove the shock mount/leaf spring clamp
Congratulations, your "old" axle assembly can be removed from the vehicle. :thumbsup:

This is a great time to replace the U-joints on your rear driveshaft. It is more of a preventative measure done now rather than having to do it later.

Now we will focus on the replacement axle housing assembly.

If you have a set of extra jack stands it would make this easier, but it is not a requirement.
Get that catch pan again
You need to disassemble this axle assembly just like your “old” one so that you can replace the backer plates and clean that thing up before hanging it.
Keep in mind that the axle shafts are different lengths. You will know which one goes where when you try to re-install them if you forget which side is which.
Once the axles are out of your “new-to-you” assembly, look very carefully at the outer axle shaft end. You can see where the bearing rode on the shaft.

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3352

You want to feel that area for any imperfections or if the axle shaft has worn down. Your fingernail is the best way to “feel” this area. If the area is clean and shiny, and you can’t feel any difference in the circumference of the axle shaft, and there are zero imperfections, it’s good!
If you can feel an imperfection with your fingernail, check the axle shaft you removed from your “old” housing.
If both sets of axle shafts show signs of wear, all is not lost...yet. You could use a set of “axle saver” bearings. They ride outboard of where the existing bearings ride. Some call them a short term “band-aid” approach, but I had a set in my axle for 6 years without issue.
Using a seal remover, remove the existing axle seals, don’t scar the seal mating surface on the housing
Check out the existing axle bearings. Some will say replace them no matter what, others will disagree.. I say its up to you. If you chose to replace them, yank them out of the axle housing using the slide-hammer.
Remove the dust shields/backer plates

Now comes the real cleaning. I use brake cleaner to get the "gunk" out. Clean out what you can, but be 100% sure the brake cleaner evaporates out of there.
Clean the mating surface where your diff cover will go. Get all the old RTV sealant off of it.
Clean the area where the replacement bearing will be installed.
Apply a thin film of oil to where the new bearing will be driven. Now, drive the new bearing into position. I used a socket that very closely matched the outside diameter of the bearing casing. Do not use one that will put force on the bearing cage as that will most definitely kill your new bearing. Drive the new bearing into place, use the same method for installing the seal, and drive the seal home. I used some Vaseline on the back side of the seals to help hold the little spring in place.
Pic of driving the seal home:

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3780


Repeat process for other side.
Replace backer plates/dust shields
Replace axles (if you mixed up which side is what, you will quickly realize what side goes where)
Replace axle “C” clips, then pull axle outward a little bit
Replace cross-pin
Get your new cross-pin keeper bolt out and install it. Do not over or under tighten this. I do not know the proper torque, but just "felt" it was tight enough. Perhaps someone knows the actual torque value for this bolt?
Here is where I did something out of the ordinary. I thought it was easier than trying to fill it later. I replaced the fill plug and poured in a quart of diff fluid and the friction modifier (Needed the modifier because I had the limited slip). I coated the gears, turned the pinion from the exterior of the assembly and dumped more in. I made sure that since I cleaned this out with brake cleaner, everything was going to get a bath beforehand. I even lifted up each side of the assembly to ensure some diff fluid went down into the axle tubes. This probably wasn't needed, but it gave me peace of mind knowing the wheel bearings were pre-soaked with fluid. Then I dumped the remaining diff fluid in.
Apply the RTV sealant to the mating surface of where the diff cover will go. Take a break while it sets up.
Replace the diff cover, tighten bolts
Reinstall brakes here (mount the calipers; bend the brake line that crosses over the rear end and attach to calipers, install parking brake hardware etc)

Install is the reverse of removal.
Don’t forget to pre-adjust your parking brake shoes and bleed your brakes. Start with the passenger side rear, the drivers side rear, then passenger side front and lastly drivers side front. I know that bleeding the fronts is not really necessary at this time, but it is a great time to bleed out all that old brake fluid in the system and replace it with new.


Torque Specifications (Lb-ft unless otherwise noted)

Rear sway bar mounting nuts: 30-40
Rear sway bar link nuts: 50-68
Shock absorber lower bolt: 46
Shock absorber to frame bolt: 17
Rear driveshaft flange to rear axle pinion flange: 83
Rear driveshaft to transfercase: 64-87
Rear diff cover bolts: 33
Anti-windup bar bolts (if so equipped): 83-112
U-bolts over axle through lower shock mount: 85
Brake hose junction block: 62 INCH/Lb.
Rear brake caliper bolts: 20
Rear wheel disk brake adapter bolts: 80
 



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Axle-Saver Bearings

Great write-up! I'm not swapping axles, just doing bearings, seals, and e-brake rebuild...

I can't seem to find the "axle-saver" bearings anywhere... all the online stores I've checked (napa, auto-zone, rockauto, apw) only have the standard bearings for the rear.

Does anyone know who sells the rear "axle-saver" bearings?

BTW - Stock 97 4.0 EB 4WD
 












Only one comment - I would replacee the parking brake shoes, springs, etc BEFORE I put the axles back in. That job is much easier without the axle end plate in the way.
 






rear gear oil replacement

I'm trying to replace the rear gear oil and my bf keeps saying there's a bolt. Does anyone have a pic of where exactly this is, so I can do this by myself??
 






I'm trying to replace the rear gear oil and my bf keeps saying there's a bolt. Does anyone have a pic of where exactly this is, so I can do this by myself??



There is a fill hole on the front of the rear axle. You can either suck out the old fluid or remove the diff cover and let it drip out then refill.
 






I'm trying to replace the rear gear oil and my bf keeps saying there's a bolt. Does anyone have a pic of where exactly this is, so I can do this by myself??

I assume that you mean the rear differential fluid. Not sure about your 91, but in my 97 there is no drain plug. You have to remove the rear differential cover to drain the old fluid, then use RTV to form a new gasket when you replace the cover.

BUT FIRST: The fill hole is on the front side about 3/4 of the way up. the plug has a square 1/2" fitting; use the naked end of a 1/2" breaker bar to get it loose. It will probably be very tight - MAKE SURE that you can loosen it before you pull the back and drain the existing fluid. Not good to drain it, THEN find that you cant get the fill plug out!!
 






I am replacing the plate that hold the caliper in place because an arm broke off and the wheel studs on my "95 Explorer. This is my first time removing an axle from any vehicle. What seals and assembly is a must replace. I am going for the lowest possible cost. Addition to that... Do I have to have the emergency brake re-installed? The last one I kind of just beat off. Im on an extremely tight budget. How much fluid do I need to put back into the differential?
 






I saw this thread and thought I would go ahead and post this. I wrote this a couple of months ago, but I lost the pics I took along the way because the memory card in my camera died a horrible death.

This is how I did this. This is NOT the only way of doing it. There will be many differing opinions on what to do.

First a disclaimer:
I am not a mechanic, I do not play one online.
I used all the proper safety equipment that I felt was necessary. I am not disclosing what I used in its entirety and can not be held responsible for your actions if you choose to disregard common sense or if you fail to protect yourself. Your safety is in your hands. Working on vehicles can cause serious bodily harm, including death.
I will assume that you know how to protect yourself.
-----------------------------------------------------------------------------------------------------------
As a side note: I do not have the "air ride" suspension. If you do, there will be a few things you will have to do differently.

Ensure you get the same gear ratio that exists in your truck now. It is essential that the gear ratios match front and rear.
If you do not know what your ratio is, there is a sticker in the drivers door jamb that has a code on it that will look like this:


picture.php

http://www.explorerforum.com/forums/picture.php?albumid=294&pictureid=3739

Circled in red is what your looking for. The codes for ratio and open or limited slip diff are:

Door Code - open or limited slip - ratio
41........….…… Open 8.8"…....….... 3.27
42..…......……. Open 8.8".….…...... 4.10
43..……......…. Open 8.8"…..…...... 3.08
44..………....... Open 8.8"….…....... 3.73
45..…..…....…. Open 8.8".….…...... 3.55
46..……......…. Open 8.8".……....... 3.73
D1..……......…. L/S 8.8".…...…...... 3.27
D2...…......…… L/S 8.8".…...…...... 4.10
D4...….....……. L/S 8.8".…...…...... 3.73
D5..……......…. L/S 8.8".……......... 3.55

Forgive me for not keeping a running inventory of the tools I used, but If you are considering doing this job and have a good selection of wrenches (SAE and metric) as well as sockets (SAE and metric), breaker bars, a BFH, rubber mallet, seal remover, seal driver (pro grade or “hillbilly” grade doesn’t matter as long as it works), screwdrivers, brake tubing bender and a good selection of pliers, you should be all set.
You will need a slide hammer to remove the axle bearings if you decide to replace them, more on that later.

Before you start a shopping list:

Rotors (maybe)
Brake pads (maybe)
Synthetic diff oil- 3 qts.
Friction modifier (if you have the limited slip diff)
New axle seals and axle bearings (maybe on the bearings, your decision but a really good idea)
RTV sealant
Look at your rear shocks..replacements?
New shock mounting bolts (you might need these, I did)
U-joints for both positions on rear driveshaft (again, not vital, but a really good idea)
Brass junction block and Teflon tape as outlined below (not vital, just another good idea)
I forget what length brake line is needed to cross over the housing, measure this before you go to buy one
Tubing bender
Tubing cutter
Brake fluid
In all likelihood, you will need new parking brake shoes, they tend to fall apart
New cross-pin keeper bolt (the small bolt that holds the cross-pin that holds the spider gears in place, notorious for breaking, never re-use it)
4 new U-bolts (I am from the school where you never re-use U-bolts on leaf springs, some people will disagree)
Parking brake hardware kit (new springs, keepers and star wheel adjuster)
Brake-kleen (I used about 4 cans)
Crap-load of rags
Catch pan for old oil
Maybe even a rattle can of paint to dress up your "new-to-you" axle assembly and/or diff cover

Now, Let’s get busy:
Before doing anything, remove the fill plug on your “new to you” axle housing. It just makes sense to do this now so that you can address any problems with the plug before you need the housing. Sometimes the plugs are stuck and if you can not get it out, you will need to find a way to refill your differential.

Jack up the truck, place jack stands under the leaf spring to frame connection under the rear doors.
Remove tires.
Place a catch pan under the diff cover, loosen the bolts on the diff cover, and tap a screwdriver between the diff cover and the mating surface. Allow the differential to drain.
Remove rear shocks.
Remove the rear sway bar from the axle housing, and sway bar links from rear sway bar.
Remove the "third shock" if so equipped
Remove the “anti-wrap” bars if you have the V8 model
Remove rear driveshaft (make a reference mark on the driveshaft yoke to the transfercase flange to ensure proper orientation upon re-install))
Unplug the ABS sensor
Remove brake calipers; hang them by tie-wire, not by the rubber hose
Remove the bolt holding the brake junction block on both sides of the truck (the block between the hard brakeline and rubber hose)
Remove the rotors. You might have to back off the parking brake adjustments, a very similar setup as the drum brakes of the past. Even then sometimes you will need a BFH and beat the rotors off the axles.
Remove the parking brake shoes and hardware.
Loosen the hard brake line on the drivers side CAREFULLY and remove it from the block.
I got a Brass junction block at Lowes beforehand that had the same threads as the brake line, a bolt that would thread into the junction block and some Teflon tape. Wrap the Teflon tape around the bolt; thread the bolt into one end of the junction block.
Thread the hardline into the junction block, finger tight should do it. (this will stop the brake fluid from draining out of your system)
Go over to the passenger side, disconnect the brake caliper rubber hose from cross-over brake line.
The diff should be drained by now, so take the cover off all the way.
There will still be a good puddle of diff fluid in there, clean it out (easier disposal later if its clean inside)
I am going to guess that you will need to swap over your backing plates/dustsheilds because if you’re getting a replacement from the junkyard, they usually get hammered up by the yard guys dragging the assembly. If you are one of the few fortunate ones and the backer plates are good, skip down past removing the axles and the aforementioned backer plates from your “old” axle assembly.
CAREFULLY remove the cross-pin keeper bolt. Pic of bolt:

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3308

Remove the cross-pin.

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3123

Push one axle in far enough so that you can remove the “C” clip in the differential. Pic of what a C-clip looks like in the differential

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3779

Remove the C-clip and then slide the axle out of the housing, repeat for the other side.
Unbolt the backing plates from the existing axle housing, 4 bolts per side. Set them aside. The parking brake pawl will slip out. I studied (and photographed and lost the pictures) how this all fit in the backing plate before I disassembled it, you might want to do that as well so you know how it all goes back together. (just don't lose the pictures obviously)
Loosen the 4 U-bolts that hold the housing to the leaf springs and remove them
Remove the shock mount/leaf spring clamp
Congratulations, your "old" axle assembly can be removed from the vehicle. :thumbsup:

This is a great time to replace the U-joints on your rear driveshaft. It is more of a preventative measure done now rather than having to do it later.

Now we will focus on the replacement axle housing assembly.

If you have a set of extra jack stands it would make this easier, but it is not a requirement.
Get that catch pan again
You need to disassemble this axle assembly just like your “old” one so that you can replace the backer plates and clean that thing up before hanging it.
Keep in mind that the axle shafts are different lengths. You will know which one goes where when you try to re-install them if you forget which side is which.
Once the axles are out of your “new-to-you” assembly, look very carefully at the outer axle shaft end. You can see where the bearing rode on the shaft.

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3352

You want to feel that area for any imperfections or if the axle shaft has worn down. Your fingernail is the best way to “feel” this area. If the area is clean and shiny, and you can’t feel any difference in the circumference of the axle shaft, and there are zero imperfections, it’s good!
If you can feel an imperfection with your fingernail, check the axle shaft you removed from your “old” housing.
If both sets of axle shafts show signs of wear, all is not lost...yet. You could use a set of “axle saver” bearings. They ride outboard of where the existing bearings ride. Some call them a short term “band-aid” approach, but I had a set in my axle for 6 years without issue.
Using a seal remover, remove the existing axle seals, don’t scar the seal mating surface on the housing
Check out the existing axle bearings. Some will say replace them no matter what, others will disagree.. I say its up to you. If you chose to replace them, yank them out of the axle housing using the slide-hammer.
Remove the dust shields/backer plates

Now comes the real cleaning. I use brake cleaner to get the "gunk" out. Clean out what you can, but be 100% sure the brake cleaner evaporates out of there.
Clean the mating surface where your diff cover will go. Get all the old RTV sealant off of it.
Clean the area where the replacement bearing will be installed.
Apply a thin film of oil to where the new bearing will be driven. Now, drive the new bearing into position. I used a socket that very closely matched the outside diameter of the bearing casing. Do not use one that will put force on the bearing cage as that will most definitely kill your new bearing. Drive the new bearing into place, use the same method for installing the seal, and drive the seal home. I used some Vaseline on the back side of the seals to help hold the little spring in place.
Pic of driving the seal home:

picture.php

http://www.explorerforum.com/forums/picture.php?albumid=286&pictureid=3780


Repeat process for other side.
Replace backer plates/dust shields
Replace axles (if you mixed up which side is what, you will quickly realize what side goes where)
Replace axle “C” clips, then pull axle outward a little bit
Replace cross-pin
Get your new cross-pin keeper bolt out and install it. Do not over or under tighten this. I do not know the proper torque, but just "felt" it was tight enough. Perhaps someone knows the actual torque value for this bolt?
Here is where I did something out of the ordinary. I thought it was easier than trying to fill it later. I replaced the fill plug and poured in a quart of diff fluid and the friction modifier (Needed the modifier because I had the limited slip). I coated the gears, turned the pinion from the exterior of the assembly and dumped more in. I made sure that since I cleaned this out with brake cleaner, everything was going to get a bath beforehand. I even lifted up each side of the assembly to ensure some diff fluid went down into the axle tubes. This probably wasn't needed, but it gave me peace of mind knowing the wheel bearings were pre-soaked with fluid. Then I dumped the remaining diff fluid in.
Apply the RTV sealant to the mating surface of where the diff cover will go. Take a break while it sets up.
Replace the diff cover, tighten bolts
Reinstall brakes here (mount the calipers; bend the brake line that crosses over the rear end and attach to calipers, install parking brake hardware etc)

Install is the reverse of removal.
Don’t forget to pre-adjust your parking brake shoes and bleed your brakes. Start with the passenger side rear, the drivers side rear, then passenger side front and lastly drivers side front. I know that bleeding the fronts is not really necessary at this time, but it is a great time to bleed out all that old brake fluid in the system and replace it with new.


Torque Specifications (Lb-ft unless otherwise noted)

Rear sway bar mounting nuts: 30-40
Rear sway bar link nuts: 50-68
Shock absorber lower bolt: 46
Shock absorber to frame bolt: 17
Rear driveshaft flange to rear axle pinion flange: 83
Rear driveshaft to transfercase: 64-87
Rear diff cover bolts: 33
Anti-windup bar bolts (if so equipped): 83-112
U-bolts over axle through lower shock mount: 85
Brake hose junction block: 62 INCH/Lb.
Rear brake caliper bolts: 20
Rear wheel disk brake adapter bolts: 80
 






This is an awesome write up. I was nervous about swapping axles. My 95 XLT sat for 3 yes with a 2 in play in the pinion flange. I found a similar yet newer recycled 3.55. I followed these directions slowly over a weekend . No more loud hum/whine. I learned a lot as I went and gained some personal confidence. Now on to the next vehicle. Thank you My Posts Mounty.
 






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