1970 Ford Bronco - Swiss-Watch-Precision C4

To complete the first subassembly, Mike installed the sun gear, thrust washer No. 5, and the input shell (a.k.a. sun-gear shell).

Mike placed the input shaft in the just-completed subas-sembly.

Focusing on the output shaft, Mike installed the governor and applied assembly oil. The output shaft is comprised of governor valves and a distributor.

Mike applied LOTF to the governor distributor sleeve, since the opening would be receiving the governor-equipped output shaft, imminently.

With the trans case standing on end, Mike carefully installed the one-way clutch-equipped output shaft in the governor distributor sleeve.

As seen from the top of the trans case, he inserted the low and reverse drum into the output shaft, within the trans case.

A Tru-Arc snap ring was installed--this holds the output shaft and the low/reverse ring gears in place.

After soaking the low/reverse band in Mercon Transmission Fluid for at least 10 minutes, it was nested over the low/reverse drum.

Mike installed the band struts, which will clamp the low/reverse band tight to the low/ reverse drum when under hydraulic pressure. After installing the bands, he checked that they were working properly with compressed air (not shown).

To prevent any hydraulic transmission-fluid leakage, Gasgacinch gasket sealant was applied to the purple anodized billet- aluminum housing that houses the Sonnax Industries Second-gear servo piston, prior to fitment of the gasket.

Mike liberally applied grease to the Second-gear servo-piston sleeve, to diminish wear to the Teflon sleeve and prevent fluid leaks. He also lubed the black ring seals (not shown).

Since the Second-gear servo piston is under spring tension, both father and son Piraino installed the billet servo piston.

Before torquing the Second-gear servo-piston housing, Mike referred to the C4 assembly manual for the proper torque specs.

Mike torqued the Second gear servo piston housing to 16-22 lb-ft, as the manual specified.

After nesting the planet carrier within the reverse ring gear and hub (circular object in background), Mike installed the throttle-valve lever onto the side of the trans case.

Compressed air was used to test that the Second-gear-servo piston functioned properly. You can see the piston poking out where the notch is at the bottom of the trans case.

Mike installed subassembly one next. To refresh your memory, subassembly one consists of: the reverse and high clutch drum, the forward clutch and cylinder, thrust washer No. 3, the front ring gear, thrust washer No. 4, the front planet carrier, the input shell, the sun gear, and thrust washer No. 5.

After installing the intermediate band, Mike equipped the intermediate servo piston (Second-gear servo piston) and the adjusting nut with struts. He used compressed air to ensure that the intermediate band clamped properly.

In anticipation of installing the oil pump, Mike liberally applied assembly lube (LOTF).

Using a Philips screwdriver as a guide, Mike installed the oil pump. He torqued the pump's fasteners to the specified 28-40 lb-ft.

The low/reverse-band-adjustment nut can only be used once, since it has a silicone seal that gets compressed to seal upon tightening (prevents ATF from leaking past threads). Mike adjusted the low/reverse-band nut the specified three turns. The intermediate adjustment nut is shown in the foreground. It was next installed on the other side of the trans case. Its proper adjustment is 1.5 turns. Every time an auto trans is serviced, these adjustment nuts should be replaced and readjusted.

After removing the rebuilt valve body from the Ziploc bag, Joe pointed out the floating manual valve of the renewed valve body. The top notch in the floating manual valve indexes with a nub inside the transmission. In addition, the kickdown lever (throttle-valve assembly) pushes on the valve to the right of the floating manual valve. For proper installation of the valve body, both of these valves must be correctly indexed.

Before torquing the valve body to the top of the trans case, Joe tightened the bolts with a speed wrench. He used vice-grip pliers to hold the kickdown lever (throttle valve assembly) in the correct position, to correctly mate with the valve adjacent to the floating manual valve. The roller of the detent spring also must be centered on the rooster cone. As to spec, the valve body was torqued to 80-120 In. Lbs. (10 Ft. Lbs.).

For safety sake, WTS puts a magnet inside the trans oil pan. Mike tightened and torqued the oil pan over the valve body (not shown).

Joe showed how the input shaft is supposed to go into the front of the trans, just before his son installed it.

Minutes before Mike torqued the extension shaft housing to the back of the trans case, he installed the extension-shaft-housing gasket with Gasgacinch gasket sealant.

With the help of his dad, Mike torqued the bellhousing (torque-converter housing) to the front of the trans case next.

An Art Carr heavy-duty shifter reposes in front of the just finished Ford C4 Cruise-O-Matic. Before WTS mates the renewed trans with the engine, they'll install a new torque converter, which they procured from Orange Coast Torque Converters in Costa Mesa, California. Thanks to Westminster Trans-mission Service and the various component manufacturers, we don't think our Bronco friend will be busting the reverse band on his newly bulletproof C4 anytime soon.