How to Replace Toyota Pinion Oil Seal in Rear Differential/3rd Member


Welcome back to the 6th Gear Garage. If you’re new to the channel, let me introduce
my 1985 Toyota Xtra Cab. Today I’m going to replace the rear differential
pinion oil seal. Every once in a while I’d have a little
drip of gear oil, right here, after driving. During driving, the wind will actually blow
the drip back So you can see the underside of the 3rd member is also wet with gear oil. Those are signs of a leaking pinion oil seal. I bought a new one, from Toyota. This seal is used on a lot of different Yotas. I’ll put the part number, as well as all
of the tools I use today down in the description. Before I take anything apart, I want to be
sure the driveshaft is marked in line with the flange. The driveshaft is balanced from the factory
this way and re-installing it 90 or 180° off can cause vibrations. I had this marked from a previous video where
I changed the center carrier bearing, but let’s put a fresh mark on there. If you look over here, you can see one of
those factory weights on the driveshaft. Now I’m removing the 4 driveshaft bolts. On this 4WD Pickup, the bolts are 14mm. It’s stuck on the flange, so I’ll give
it some taps with a mallet. There we go… Now just angle the driveshaft off to the side,
out of the way. Alright, now I have a full view of the companion
flange and the shiny nut that holds it on. It’s staked to prevent it from coming loose,
so I’ll need to punch that out with a small punch or a little chisel. Now I need to block the wheels And Set the Parking Brake I’m also going to put it in 4wd And lock the front hubs. That’s to prevent the truck from rolling. Or you can have someone stand on the brake
pedal for this next step. Get a 30mm socket to remove the nut. When I turn this counter clockwise, it’s
going to make the truck roll backwards. So keeping the truck from rolling is the only
way to get this loose by hand, unless you have a good impact. Mine is on its last leg. There we go. Important note: count the number of turns
it takes to remove the nut. Some trucks, including this one, use a crush
sleeve on the pinion, some older models use a solid spacer. Rather than take the entire 3rd member apart
to replace the crush sleeve and adjust the preload & re-torque everything to 253 ft lbs…
counting the turns will let me get the nut back to where it was and then I’ll just
torque it back to 90 ft lbs. That should leave the crush sleeve and preload
as it was, saving a lot of time and labor. I’ve read about this method on numerous
forums over the years and it keeps me from tearing apart the entire rear diff. If you want the full instructions for replacing
the crush sleeve, I’ll put a link to the factory service manual in the description. Notice there’s a washer behind the nut. Don’t forget to put that guy back on later. You’re going to need a puller to get the
companion flange out. I’m sure They make a special one for this
job and I don’t have it, but I have this old steering wheel puller that will do. Here’s the backside of the companion flange…
pretty gross. I’ll clean this up later. There’s the leaking pinion oil seal, also
covered in grime. Looking it from the side, you can see it’s
almost flush with the housing. It’s really close, probably sticking out
about 1 mm. So I’ll be sure to take note of that when
I’m driving in the new seal… stop just before it’s flush. Be sure the new seal is the same as the old
one because it’s not too late to re-assemble and go get the right one. We’re about to cross the point of no turning
back when I pull out this old seal. I’m using a big flathead screwdriver for
this. I have a couple of seal pullers but none of
them fit here. So if you’re using a flathead, just be sure
not to press on the splines of the pinion with the side of the screwdriver. Starting to get some movement… I’m mangling this seal with the screwdriver… You see why there’s no turning back now. If I was rich, I’d buy all the Toyota Special
Service Tools they talk about in the service manual, just to see how much easier they make
these jobs. Cmon… There it is! But when you’re on a budget, a craftsman
flathead will have to do. That’s the oil slinger right there. I don’t need to mess with that though. I’m just going to wipe the inside of the
housing down here and that will give me a clean surface to install the new oil seal. Sometimes I put these in the freezer to slightly
contract the seal and help it go in easier, but it’s winter in Ohio now and my garage
isn’t heated, so no point in doing that today. I wiped some grease around the edge first
to help it slide in. If you have a 4wd Toyota Pickup, you should
already have one of these 54mm sockets for the front axle nut. Turns out it’s just the right diameter to
drive in the oil seal. I’m using a rubber mallet – not a hammer. Making sure to hit the socket square on so
the seal goes in evenly. Right side is out a little further, so I’ll
work on that side more. Remember I want this to be about 1mm away
from flush, so I have a ways to go yet. I’m getting closer now. Almost there… only a couple mm to go. Alright, that’s perfect. I should have put a little grease or oil on
the inside of the seal before I installed it. Now there’s not enough room to get my finger
in there. So I’m using this little tip on this pressurized
grease can to squirt some on the edge of the seal. That way it’s not dry rubber on the companion
flange. And here is the companion flange, now cleaned
up thanks to some rags and brake cleaner. I’ll put a little bit of grease on the outside
of it too, where it meets the oil seal. Get it lined up… and press it on. I’m just going to give it a few taps with
the mallet and socket to get it started here… Ok now I have the Washer and nut. Now here’s where I have to pay attention. Earlier when I removed the nut, it was about
8 and a half turns to take it off. So I’m going to hand tighten it with the
socket so I can count the turns. 3 4 5 6 7 and that’s almost 8. This hole in the socket is a good way to count
the number of turns. I have my ‘ol torque wrench here and we’re
going to do 90 ft lbs. That’s enough to tighten the nut and not
crush the sleeve any further. I read the sleeve doesn’t start to crush
until like 130 ft lbs. As I mentioned earlier, you can follow the
manual and tear apart the whole diff, replace the crush sleeve, check the preload, torque
to 253 ft lbs, my torque wrench only does 150…. and re-torque… I’ll put a link to the whole process in
the description if you’re interested in that. Now I’m turning the pinion clockwise, so
I need to chock the wheels from the other direction because it’s going to want to roll forward. So here I’m going from hand tight to 90
ft lbs. I’d say that’s another half turn…. and
then some. Alright it’s getting pretty tight. You can see the pinion is turning with the
wrench a little. This is where it would be ideal to have someone
stand on the brakes. I see the edge of the nut that was staked
and it’s almost at the notch in the pinion. There’s 90 ft lbs. And there is the old stake, lining back up
with the notch. Perfect! By the way, you’re supposed to replace these
nuts once they’ve been staked. I usually use them a couple of times if the
edge doesn’t get too beat up from staking it. Now I’m just going to re-stake the nut at
the notch. Being sure that my marks lined up, I re-installed
the driveshaft with the four 14mm nuts and bolts. If your marks or holes don’t line up, just
put the truck in 2wd and roll it forward or backwards. Those driveshaft bolts get torqued down to
54 ft lbs. Now let’s check the fluid. If you had a leaking oil seal, it’s a good
time to top off the gear oil. The fill plug is 24mm and the fluid should
be filled right to the bottom of the fill plug opening. It’s hard to tell with this light, but it’s
a tad low. I have some 75w-90 to top it off. You probably can’t tell, but that’s the
level it should be filled to. Any more fluid and it would start to run out
of the fill hole. Well that’s it for this job. Do me a favor and give this a thumbs up if
you found it helpful. That really helps the channel grow. Consider subscribing for more how-to videos
and project vehicle updates, here at the 6th Gear Garage. Thanks for watching today’s video all the
way to the end. I have a 6th Gear Garage sticker, ready to
mail to the first person who correctly guesses the tire size on my truck. Good luck!

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