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Eaton 2-speed rear axle hub on a 2-ton 350 COE 24' bed

Replacement of the rear-wheel bearings

First: here are a few photos before disassembly.
- before starting the disassembly;
- before removing the dual wheels (ten, 1 1/16" hex-head Marsden nuts), and
- before removing the rear-axle cover-plate (five, 1/2" hex-head bolts).

Left: dual-wheels on the axle
Middle: rear-end & springs
Right: GMC embossed on cover

differentialdifferential close-up

 

The cover plate comes off quite easily, and the floating hub and axle is exposed.

To remove the axle, a puller-bolt was screwed into the threaded center of the axle.

 

The axle is then simply pulled out of the the axle housing. Pull about 2" and the axle shaft is loose.

 

The axle is then pulled out of the shaft.

 

This is what the rear axle hub looks like from the top.
The two wheels have been removed and the brake drum has been removed
(note that during this job the two rear wheel brake cylinders have been replaced - the old ones are good and will be kept as "traveling spares").

 

The rear axle hub contains are the bearings, races, and a rear seal.
The hub pulls right off the axle and travelled to the bench for disassembly, cleaning, and re-assembly (new races, bearings, and seal).

It is hard so see, but the forward tab/finger on the lock had been bent into the notch at about 7 o'clock.

 

A closer-up photo of the outer nut - a better view of the lock's fingers.

 

The outer nut is held on the left; the lock is still in place (with the inner nut behind the lock).
There is a tab on the inside of the lock ring (it goes in the slot at the bottom of the axle housing)

 

The lock-ring ("ring") is being held on the left; the inner ring-nut ("nut") is still in place.

 

The inner nut has been removed;
there is a thick washer now viewable, outside of the outer bearing
(this washer also has a tab on the inside (that goes in the slot at the bottom of the axle housing).

 

For some reason (greasy hands?), I did not take many photos of installing the races and bearings.
The procedure is clearly described in the Maintenance Manual and is not much different than installing the bearings and seals in a light truck front wheel.
One difference is that the bearing sets are both punched-out from the rear side of the hub.

The old bearings and seals were punched-out using steel drifts and a little persuasion.
(hooray for the 20 piece Harbor Freight drift set that I bought years ago - for $10).

- The inner bearing/race/seal are punched out first.

- There is a spring clip that sits in a groove and holds the outer bearing in place (seems odd) - see the installed races in the pictures below.
I grabbed one of the tanged-ends of the spring and pulled it out slightly.
A screw driver was then slipped between the spring and the hub body. I was then able to "screw out" the spring.

- The outer race is then punched out.
There is not much of a lip to hit the drift against (I ground a good clean edge on the drift and was able to catch the edge on the race).

The new races went in quite easily, using the old races to hit against with a small hammer
(I froze the races - I guess this helps). Both races are already in place in the three photos, below.

- The outer race is pressed in first (it is deep inside the hub - the spring lock is already in place).

- The outer race stop-spring in pushed down into place inside the hub.

- The inner race is pushed into place.

 

On the axle is a hub backing plate that has a "race" and a seal.
The rear bearing seal rides on the race and there is a thin seal on the lower/forward edge of the "race"
(the arrow is pointing at the black seal - sorry about the quality of the picture).
This seal was in good shape - a good thing, because I bet a replacement would be hard to find.

 

The hub is installed on the axle and seated into place.

 

Here's a look again at the hub from the top.

 

The flat washer is installed (the tab goes into the slot in the axle housing at 6 o'clock).

 

The first axle nut is installed and "torqued" to 30-50 ft-lbs :rolleyes:

 

The lock (washer) in put into place; and,
by trial-and-error (removal and replacing) the nut is tightened until a finger in the lock is over a notch in the nut (at about 7 o'clock).
The lock has a tab at 6 o'clock that goes into the slot at the bottom of the axle housing.

 

The finger is punched down into the notch.

 

The outer nut is spun into place and then punched firmly (100 ft-lbs) until a finger lines up
(at about 10 o'clock - the finger tip is still pointing outwards)

 

The finger is then bent into the notch and everything is now locked into place.
The wheel still spins smoothly but there is no looseness in the bearings.
We bent all the unused fingers a little bit inwards towards the axle housing
(it looks like this step had been neglected in the past - the inner surface of the axle housing had been well-scoured by fingers that were spread too far outward).

 

The next two photos are of the lock on the other side of the axle.

- This shows once again how the lock has a finger punched back into a notch in the rear nut (11 o'clock).

- And then, the outer nut is installed and a finger is bent over a notch in the front nut (9 o'clock).

 

The cleaned axle is then put back into the axle shaft.

When the axle reaches the differential gears, it has to be moved around until the splines line up and the axle slides in until the outer teeth drop into the axle housing.

 

The floating axle is now seated.

 

We used RTV seal on the outer cover.

 

The rear axles are now ready for a test ride.

 

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