C 1500 1/2 Ton Pickup 2WD V8-305 5.0L VIN F 4-bbl (1983)
Governor: All Technical Service Bulletins
A/T - THM 700-R4 Erratic or No Upshifts
Number:
84-13
Section:
7A (VIIc)
Date:
Oct., 1983
Subject:
ERRATIC OR NO UPSHIFTS
Model and Year:
THM 700-R4
TO:
ALL CHEVROLET DEALERS
In diagnosing any THM 700-R4 transmissions for erratic or no upshifts, the cause may be from a worn governor gear. The cause of the worn governor
gear may be from one or more of the following conditions:
1.
The output shaft to input carrier assembly snap ring came off.
2.
Metal scale on the output shaft gear.
3.
The governor dowel pin dimension may be incorrect.
4.
An incorrect governor gear may have been installed.
When servicing any THM 700-R4 transmission for an erratic or no upshift condition, refer to the following diagnosis chart.
Follow guidelines given in your service manual for servicing the transmission governor gear.
FIGURE 1 - GEAR WEAR "APPLECORED"
CONDITION
CAUSE
CORRECTION
1.
Governor gear 1. Flash, scale or 1. Replace governor is worn in an nicks on the gear (P/N "Apple Core" output shaft
8642928) wire
shape (refer
gear.
brush output
to Figure 1).
shaft gear to
2.
Incorrect goverremove scale of nor gear (THM flash. Replace 350C type). output shaft if
nicked.
2.
Replace governor gear (P/N 8642928). Do not use THM 350C type as replacement.
FIGURE 2 - GEAR WEAR IN THE MIDDLE, ON ONE SIDE ONLY