A/T - 404, 413, 470 Ring and Transfer Shaft Gears

SIL 87-20 (June)

SUBJECT: 404/413/470

Servicing Ring and Transfer Shaft Gears

When servicing ring and transfer shaft gears, many shops are replacing only the ring gear, or the transfer shaft. When replacing only one, the replacement must have the same number of teeth, and the same number of identification marks.




Look at the top of each tooth on the defective gear and the replacement. The number of identification marks indicate different pitch, or angle, of teeth on that gear. Using gears with the same number of teeth, but a different number of identification marks may lead to excessive noise from the ring and transfer shaft and/or early failure.

THE FOLLOWING IS INFORMATION ON PART NUMBERS AND RATIOS TO BE USED WHEN REPLACING FINAL DRIVE GEARS

Two combinations are found on the early units:

Ratio of 3.05 Ratio of 2.84
55 tooth ring gear 54 tooth ring gear
18 tooth transfer shaft 19 tooth transfer shaft

The replacement for both of these combinations has a 3.05 ratio. The following part numbers are available until stock is depleted. When these part numbers are depleted, use the part numbers listed at the bottom of this page -- they will retrofit, but both gears must be replaced when those gears are used on the early units.

4205868 55 tooth ring gear and 18 tooth transfer shaft with 2 groove ID mark
4131050 55 tooth ring gear and 18 tooth transfer shaft with 1 groove ID mark

IN 1983 A DECISION WAS MADE TO SERVICE GEARS SEPARATELY. THE PART NUMBERS ARE AS FOLLOWS

Ratio of 2.85 (can be used on the 2.84 ratio of the earlier models, but both gears must be replaced)

4295841 60 tooth ring gear
4295842 21 tooth transfer shaft

Ratio of 3.05 (can be used on the 3.05 ratio of the earlier models, but both gears must be replaced)

4269171 61 tooth ring gear
4269172 20 tooth transfer shaft

RATIO IS ACCOMPLISHED BY DIVIDING THE NUMBER OF RING GEAR TEETH BY THE NUMBER OF TRANSFER SHAFT TEETH