Front axle basics: Pinion seals and axle seals
Copyright © 2012 by D44Tech.com · All Rights reserved
DANA 44 FRONT AXLE TECH
On a Dana 44 there are only a few places that water/dirt can get in and oil can get out. The pinion seal behind the pinion yoke, the 2 axle seals inside the axle tube, the differential cover and the vent tube are the only ways in or out. The diff cover is simple enough to seal with either a gasket or some RTV. The vent tube can be routed up high into the engine compartment with some hose. The pinion and axle seals either work or don't work - once they have gone bad and start to let water in and oil out they need to be replaced. Here is how to do it youself.
The first step in replacing the axle seals is to remove the carrier. It is important to keep the carrier bearings on the right side - you can see that they are stamped with letters that match. On this axle they are "m"s, one side has them upright one side is sideways - keep them laid out right and you will be fine.
Once you have the carrier bearing bolts out and the caps off - you can pop the carrier out with a pry bar. Be sure and get ready to catch it when it pops.
Oopps. Looks like we let this axle seal go a little long. You can see the dirt and grim that was been working its way into the differential.
To get the inner axle seals out I use a piece of pipe or a broom stick with a flat end. Slide it into the tube and then angle it into the axle seal where it meets the axle tube. Once you have it in the 'spot' give it a whack with a hammer and the seal should start to pop out.
You can see the pipe angled into the edge of the axle seal.
Matching letter stamps - this side they are upright - the left side has them rotated 90 degrees.
Bearing cap torque for a Dana 44 is 60 ft-lbs - be sure and clean the threads and the hole before torquing. I add a drop or two of loctite for good measure.
This is what a new seal looks like - the side with the spring goes IN.
I use a big socket for my seal press tool. They make actual seal installation tools but this works fine for me.
A few taps with a hammer and you are good to go.
This is the seal correctly installed. You can see the spring.
The pinion seal works the same way - remove the pinion nut. Tap off the yoke and pry out the old seal. Press in a new one. The spring goes IN as well. Then the pinion yoke goes back on and the nut is torqued back down.
I use a large pipe wrench to hold the pinion in place when removing or installing the pinion nut. There is a torque spec and you should check for your exact make and model Dana 44. It is also wise to use a new pinion nut each time it is removed.
With all new seals in place you can drop the carrier back in. Make sure you get the bearing caps on the right sides and the bearing caps on the right side and direction. Check the Stamps! When you get it in place as seen above it might need a few taps with a rubber mallet to drop into place - do not hammer it just bump it. Once it is fully seated - reinstall the bearing caps.
And with any luck you now have a fully water/oil tight Dana 44 with all new seals.