Quantcast Changing oil in an 8.8" Rear axle - Ford Truck Club Forum








New Posts






FTC Toolbar

Social Sites

Log Out

Ford Truck Club Forum > GARAGE TALK > Garage Talk: Shop Class 101

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools Search this Thread Display Modes
Old October 26th, 2013, 01:11 AM
BigBlue79's Avatar
BigBlue79 BigBlue79 is offline

Join Date: Sep 2011
Location: Sapulpa, OK
Posts: 5,892
Images: 1113
Likes : 14
Liked 51 Times in 44 Posts
Default Changing oil in an 8.8" Rear axle

This one is for the first time truck owner's, how to change the gear oil in the 8.8" rear axle, without using a siphon pump.

So first gather your tools, you shouldn't need an impact, I used a ratchet, 1/2" 3/8" drive deep well 6pt socket, 3" extension, 3/8" drive torque wrench, drain pan, shop towels, high temperature paint, sandpaper, Black RTV Form a Gasket, something to hang the differential cover off of.

So to start, put the drain pan under the axle, in this pic I've parked my truck where the rear was pointing downhill, here is the axle:

Start by loosening the bottom bolts working up til they're all broke free, then remove the lower bolts halfway up, loosen the top bolts a bit more, pry the differential cover away from the axle, I was able to do it with just my fingers, there's enough of a lip on the cover you might be able to as well, once pulled away the oil will run out, luckily it won't be bright silver or have chunks in it.

Once its drained, remove the last of your bolts, remove the cover, your now looking at the inside of your differential, this is the "open" differential in my 1988, 3 55:1 gear ratio, open means no limited slip unit, no locker, nothing of the sorts:

Pretty nasty in there, this rearend has A LOT of slop in it, requiring a rebuild in the near future.

So, once the cover is removed, start wiping off the differential cover and the axle, wipe out the differential itself as well, we don't want old gear oil that's as black as molasses contaminating our new oil, climb out from under there with the cover.


Hopefully you either have sandpaper, or you bought some when you bought your paint, start sanding both the mating surface and outside of the cover, matun surface you want as flat as possible, remember the RTV will help fill in some, clean it all with a towel with 91% Isopropyl Alcohol on it, then fashion up something to hang the cover from, and get your paint, color I went with:


You can see it sanded as best as possible by hand in those pics, time to start laying paint, I did three coats:

First coat:

Last coat:

I sanded the axle mating surface while waiting for the cover to dry:

Then baked the cover in the sun for an hour or so:

Once the paint is dried, time to climb back under with the cover and your RTV, take a towel and some more Alcohol and give every mating surface another good wipedown, then start applying the RTV to the cover, I usually wear nitrile gloves, and once beaded around the inside part of the cover, smooth it out flat with my finger, lay down another bead around the outside and the bolt holes, smooth it as well, then install the cover and start threading the bolts back in, snug the cover down, don't torque it yet, wait an hour and torque it anywhere between 25-35ft lbs, I did 30ft lbs:

Wait 24hrs and then add the gear oil of your choice that is GL-5 rated, I went with Walmart Supertech Synthetic Blend 75w90, $5.18/qt and best oil we sell.

The reason for doing it this way is because your able to actually look everything over and see if anything looks broken, worn out, or just to familiarize yourself with a differential.

》Sorry for the photobucket pics, I've only got a phone to get on the internet witb and photobucket is faster to upload to and get the links from, once I get internet reconnected I'll add these to the gallery and replace them.《
The Following User Likes This Post:
Booba5185 (October 26th, 2013)
Old October 26th, 2013, 10:25 AM
JSoko's Avatar
JSoko JSoko is offline


Join Date: Jun 2009
Location: Northwest Georgia
Posts: 15,072
Images: 630
Likes : 36
Liked 188 Times in 170 Posts

new shed ?

For Those Who Fought For It...
Freedom Has A Taste The Protected Will Never Know.

Old October 26th, 2013, 12:49 PM
BigBlue79's Avatar
BigBlue79 BigBlue79 is offline

Join Date: Sep 2011
Location: Sapulpa, OK
Posts: 5,892
Images: 1113
Likes : 14
Liked 51 Times in 44 Posts

We've had it, just cleared it out to start insulating it.
Old October 26th, 2013, 12:55 PM
BigBlue79's Avatar
BigBlue79 BigBlue79 is offline

Join Date: Sep 2011
Location: Sapulpa, OK
Posts: 5,892
Images: 1113
Likes : 14
Liked 51 Times in 44 Posts

Forgot to mention, in order to fill the differential, on the front of the axle by the yoke/flange(1992+ trucks had flange instead of a yoke) there is a square looking hole, that is to refill the differential or check the oil level. It takes a 3/8" drive ratchet to unscrew it, you can use an extension if it is squared and doesn't have rounded corners, I've gotten away with just a ratchet to break the plug loose.
Old October 26th, 2013, 01:13 PM
glc's Avatar
glc glc is offline

Join Date: Jul 2012
Location: Joplin MO
Posts: 1,162
Likes : 2
Liked 116 Times in 112 Posts

One thing you forgot - make sure you can get the fill plug out before you pull the cover!

2003 F-150 XL RCSB 2wd 4.2 5 speed 3.55 LS

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

(View-All Members who have read this thread : 11
ASwaff400 , BigBlue79 , Booba5185 , CountryBumkin , DoubleDee , gadget , glc , JSoko , nflfreak43 , purple lady , The Frankster

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear axle codes The Frankster 1992-1996 Ford F150
7 June 24th, 2012 07:24 PM
8.8" Rear Axle Complete BigBlue79 Auto Parts For Sale
7 May 14th, 2012 05:12 PM
HOT ROD How To: Order a Strange Rear Axle for Your Car Hot Rod Magazine Hot Rod TV 0 February 9th, 2011 05:04 PM
'96 rear 8.8 axle willys5555 Auto Parts For Sale
1 May 1st, 2010 06:25 PM
rear axle The-LI-Redneck Garage Talk: Brakes & Suspension 4 April 14th, 2010 12:04 AM

axle , changing oil in an 88 , rear

Forum Jump

   Current Advertisers Privacy Policy FAQ Home Blog Archive Top

FordTruckClub.net is not authorized, endorsed or affiliated with the Ford Motor Company
or any of their subsidiaries. Ford® is a registered trademark of the Ford Motor Company

Powered by vBulletin® Version 3.8.6 Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.