Volvo Maintenance Hints for 7xx/9xx - Bill Garland's Nuclear ...

part number is 1377746-1 (small blue valve ball). [Tip from Herman] You may need gasket kit p/n 271292. Before you do the job, buy the
OEM manual: the manual number is TP 31642/1. The manual is for AW70/70L,AW71/71L, and AW72L. The L means lockup, check the tag
on the tranny before you buy your gasket kit. For detailed instructions, see Brad Wightman's excellent illustrated writeup.
AW-70/1 Valve Body and Valve Balls
In my case the 5.5 mm valve ball was worn to about 2 mm size. Note that the valve body can be accessed through the oil pan, so it's not
necessary to drop the transmission. A competent transmission shop should be able to change this ball. In my case the cost was about
$100, this includes two hours of labour, new gaskets and fluid. [More from Herman] Great care needs to be taken upon disassembly
however it's an easy job with some potential of going very wrong. I tried the wrong way first. I disassembled enthusiastically and lost one
ball of about 15, dropped a retaining pin and then wasted 2 hours scratching my head and agonising about the lost ball. A friend had a
dead AW71 and let me take it apart for reference. This time I followed the manual and compared the two valve bodies. The job was dead
simple once I went about it the right way. GET THE MANUAL and follow the steps that get you to opening the valve body up. The manual
says nothing about the balls so you need to locate them and note ON PAPER where they go. There are a lot of balls and things that can go
flying and falling into your parts cleaner. Following the steps in the manual however, takes away that risk. As in the photo on that page, my
ball was worn to half the size of the new one and was blown out from its seat and had gone somewhere else. I think I replaced about 5
maybe 6 quarts of fluid (I use only AMSOIL). Make sure you have a lot of good quality paper towel (cloth fibre won't break down should it
get into the gubbins) for the job and a large clean well-lit bench surface.
[Tip from Gary De Francesco] Rough 1 - 2 shifts are a possible sign of a worn rubber ball in the valve body that regulates how fast the
various clutches and brakes are applied. As the ball wears, the fluid flow rates in some of these regulating passages can increase which