K 1500 Truck 4WD V8-350 5.7L (1986)
1.
After October 6, 1986 (Julian date 279) all THM 700 R4's have an auxiliary accumulator valve body. It is bolted to the case adjacent to the main
valve body. (See Figure 1) The auxiliary accumulator valve body is diecast aluminum and contains a forward clutch accumulator, an abuse shuttle
valve, and a low overrun valve (See Figure 2) to provide smooth neutral to drive shifts, increased forward durability, and smooth manual 2-1
downshifts. The number 5 checkball is in the auxiliary accumulator valve body, instead of its usual spot in the valve body (See Figure 3). A tube
feeding the forward clutch extends from the auxiliary accumulator accumulator valve body to the pump. The forward feed cup plug in the pump
has been omitted so the tube can fit in. ( See Figure 4)
2.
Since the auxiliary valve body has been added, the valve body gaskets are as follows: 8667232 upper gasket and 8663583 for the lower gasket.
The use of earlier model gaskets on the 1987 THM 700 R4 covers a 3rd clutch hole on the separator plate.
3.
The separator plate is stamped with two letter codes for identification. If the first letter stamped is "A", that plate is used with the auxiliary valve
body.
4.
The case has a window cut out of it to make room for the tube as it goes into the pump. Many 1986 THM 700 R4 cases have this provision. A
bleed orifice lube hole has been added to the governor bore. To find this, look through the back of the case where the extension housing is bolted.
5.
The transmission oil pan for the 1987 THM 700 R4 is slightly deeper to accommodate the auxiliary accumulator valve body. The 1987 models use
part number 8663618. The 1982-1986 models use part number 8654700.
