Bonneville V6-231 3.8L VIN 3 SFI (1988)
new seal, an input shaft and housing assembly, and a 3rd roller clutch. The new seal can be used in the original type input shaft and housing with the
stepped groove (Figure 2), if the shaft and housing are not damaged. If shaft and housing or the 3rd roller clutch is damaged, then the kit should be used.
INPUT SPRAG
A condition of intermittent no drive and reverse may be caused by the input sprag assembly. Dealer Technical Bulletin 86-7-53 discusses a first and
second type input sprag and their differences. The most significant difference is the width. The second type sprag is wider than the first. If you are
working on a 440-T4 built prior to April 1, 1986 which has a first type sprag and you have the transaxle apart as far as the input sprag, you should
replace it with a new first type sprag. The first type sprag you get from G.M.S.P.O. has durability improvements. You do not need to update to a second
type sprag unless the input carrier is damaged. If it is, the only new carrier available is the one used with the second type sprag. In this case the update kit
listed in 86-7-53 would be the best repair.
TRANSAXLE COOLER FLUSHING
It is very important to flush the cooler any time a transaxle is removed for repair. This would include a torque converter replacement. It is also important
to flush the cooler if the pump or valve body is removed with the transaxle in the car. Use the Kent-Moore cooler flushing tool J35944 and
Biodegradable Flushing Solution. And don't forget to do a cooler flow test as it is described in Dealer Technical Bulletin 87-7-1. Without the proper
volume of fluid (2 quarts in 30 seconds) flowing through the cooler and lines, there will not be enough cooling and lubrication capacity for the transaxle.
This of course could lead to another breakdown, unnecessary work for you, and most importantly an unsatisfied customer.
Remember to use the 440-T4/Hydra-Matic 4T60 bulletins with the following rule in mind. Unless you have the condition or damage noted in a bulletin,
you do not usually need to do the repairs or install the parts listed in that bulletin.
