I’ll give this article my seal of approval.
While doing about 44 other things simultaneously on the Dana 44 front axle install for my 1988 E250 van, I somehow managed to change out all the seals on the differential housing with minimal photos.
This isn’t really a fancy how-to about seals, but it’s still important that while we got all this crap apart, maybe invest in new seals. The old seals are likely from the original 1979 F250 donor truck.
So I’m starting this article with the diff already disassembled. If you are looking for how I did that, check this article out. There are some important things you need to do before ripping the differential pinion and ring gear and carrier out, like labeling things, so check out the previous article.
There are two races (for the bearings) in the sides of the housing, and they just drop out. Be careful with them, you don’t want to scratch them if you are reusing them. Behind the races, there are seals.
There is a left and right seal, but they are identical. They are just snug-fit into place. They make fancy tools for extracting and installing these seals, but you don’t need any of that. Just get all the socket extentions you have and your 1-3/16″ socket. From the wheel-end of the axle, run your 3-ft-long extension combo and fat socket. Push the socket up to the seal.
Then use a hammer to tap it into the diff housing. It shouldn’t take much effort.
My socket came in with a buttload of rust. Both old seals landed inside the diff housing and I grabbed them to check out my replacements. I bought a bunch.
The old axle shaft seal (left), Axle Shaft Seal: NATIONAL 5131 (middle) (Returned. Didn’t use), Axle Shaft Seal. WJB / INMOTION PARTS WS5131 (right). I used the orange seal.
- Axle Shaft Seal: NATIONAL 5131 Info. Front; 4WD; w/ 8.5 IN Ring Gear; w/ Spicer 44-9F Axle (Returned. Didn’t use)
- Axle Shaft Seal. WJB / INMOTION PARTS WS5131 Info. Front; 4WD; w/ 8.5 IN Ring Gear; w/ Spicer 44-9F Axle
- Axle Shaft Seal. NATIONAL 2300 . (I bought this because a certain Youtube video said this seal worked for my Dana 44. It did not.)
Winner Winner: (Orange) WJB / INMOTION PARTS WS5131
The National 5131 was way too small:
But the orange axle shaft seal from WJB / INMOTION PARTS WS5131 fit perfectly.
Installation is easy. Use all the combination socket extensions again, but from the other direction.
Here’s the empty axle shaft: (clean it up as good as possible)
You want to tap this in with a fancy tool from Summit, but a bunch of extensions and a hammer works fine.
Tap tap tap taperoo
Installed. Be sure to only tap on the metal parts of the seal. The rubber will flex and break with enough stress.
Next step, let’s replace the pinion seal.
I had a major PITA trying to get that pinion nut off. Tried heat three times, tried everything.
My impact driver wouldn’t make a dent. Even bent my closed end wrench trying to torque that off.
Finally broke down and ground off part of the nut. That made it budge.
Now, I could slide the yoke off with a steering/bearing puller.
The seal was destroyed from all the heat used on the pinion nut, with obviously transmitted to the shaft and melted the pinion seal plastic/rubber. So now it definately needed to be replaced. Slid out the pinion gear from the inside the diff housing and set it aside. I had a bunch of work to do with that pinion and its bearings. That’ll be in another blog post.
Popped out the pinion seal with a screwdriver.
While I got the seal off and the pinion shaft out, time for a new outer pinion bearing. The bearing and race came from this kit:
- Differential Rebuild Kit. MOTIVE GEAR RA28LRMK (Master Kit) Info. Front; Dana 44 Axle;
Last thing to do is replace the pinion seal with the fancy new one:
- Differential Pinion Seal. WJB / INMOTION PARTS WS5778 Nitrile Info. Front Outer; 4WD; w/ 8.5 IN Ring Gear; w/ Spicer 44-9F Axle
I tapped it on with a big rubber mallet and wooden oak board.
There is still 43 other things to do simultaneously on this, but at least the seals are brand new. Hopefully it’ll last another 47 years. On to pinion bearings. Ooooooh.
