GT42R, You must hve been told that by a parts guy.

Here are the part numbers for the internal parts.
ITEM NO. QTY PART NUMBER DESCRIPTION USED ON
828-006-355 Drive Unit Assembly A
410-029/R Drive Unit Assembly, Rebuilt A
828-006-459 Drive Unit Assembly B
828-006-459/R Drive Unit Assembly, Rebuilt B
1 1 828-006-460 Housing, Machined
2 1 401-175 Gear, Helical Pinion E, F
3 1 410-029/06 Gear, Helical E, F
4 1 761-870/03 Nut, Clamp E, F
5 2 410-022/19 Bearing, Cup E, F
6 2 410-022/20 Bearing, Cone E, F
7 1 410-035 Gear and Pinion Set A, E
1 410-040 Gear and Pinion Set B, F
8 1 410-022/07 Bearing, Cup C, D
9 1 410-022/08 Bearing, Cone C, D
10 1 410-022/06 Shaft, Flanged Output D
12 1 410-022/05 Spacer, Bearing, Output
13 1 410-022/11 Ring, Retaining, External
14 1 782-424 Plug, Pipe
15 12 714-143 Screw C, D
16 1 410-022/09 Bearing, Cup C, D
17 1 410-022/10 Bearing, Cone C, D
18 1 410-022/18 Seal, Lip C, D
19 1 410-022/02 Cover, Main, Machined
21 1 410-029/003 Ring, Pivot
22 2 810-017 Pin, Spiral
23 1 828-004-080 Bearing, Filler Plug G
24 2 840-037 Fitting, Grease G
25 1 828-005-540 Set, Ring G
26 70 850-017 Ball, Steel G
27 1 400-149 Ring Gear, Steering G
28 1 840-035 Fitting, Grease A
31 1 840-059 Fitting, Grease G
32 2 710-065 Screw
33 2 771-119 Washer G
34 AR 828-005-208/002 Shim C, D
35 AR 828-005-208/003 Shim C, D
36 AR 828-005-208/007 Shim C, D
37 AR 828-005-208/015 Shim C, D
38 AR 828-005-209/002 Shim, Cover C, D
39 AR 828-005-209/003 Shim, Cover C, D

That info must have come from "Wives tale Magazine"
410-029 drive unit in an easi truck is standard. No sealed units. The 7400 has similar unit 108858. You can change the seal only. No problem

Last I knew you could. Post a model and serial number of the truck and someone should be able to provide a break down.
Also most of these drive units are offered as a rebuilt from the factory and about half of what a new one is.