StudeM15A-20: November 2012

Tuesday, November 27, 2012

T9 Tranny Fun

While the tranny is out of the truck to replace the rear engine oil seal and clutch disc I thought I would upgrade it with new gears and some modifications. This modification is to seal the end of the shift rods so they don't weep oil all over the tranny case. Basically, it is a plate attached to the end of the shift rod bores that seals the end. There are two channels cut into the plate to allow the oil and air to pass to the adjacent bore to relieve pressure when the shift rod travels to the end of the bore. The plate is made from 1/4" thick, 1" wide stainless steel bar. The countersunk bores are 0.625" in diameter, centered on the plate, and spaced to match the the bores on the shift tower. The gasket is made from thin neoprene rubber.

Here is the block off plate, gasket, and attachment screws

(I have subsequently moved the channel between the bores to the other side of the screw holes)

Other side of the plate

Assembled, ready for installation

Hold plate in position and mark where the mounting holes are with a fine point Sharpi

Note: To get correct positioning, move 1st/2nd shift rod into second gear where it protrudes and position the plate over the shift rod.

Mounting holes marked

Center punch mounting hole location

Drill mounting holes. 0.159 for #10-32 screws

Tap mounting holes and mount plate

Oil drain back holes drilled just inside the gasket surface

Three holes, one for each shift rod

I also hogged out a channel for the oil to pass the shift rod with
a Dremel tool

Bell housing protrusion

Bell housing protrusion ground down to clear plate

Transmission shift tower attached
(Yellow arrow points to where the hole was drilled and taped for the vent tube)
The pipe coming out the side is the added reverse backup light switch. There is a rod inside the pipe that contacts the reverse shift rod and extends out to the push button switch mounted on the end of the pipe.