Tech article by Jon Hanna (Admin)
Manual Trans Intro
• Gear Ratio Chart

See also: Automatics
ZF 5 speed manual with overdrive
1988 or later Ford 4 wheel drive pick up with small block engine. The ZF S542 was used from 1988-1994 and the ZF S547 from 1995 on.
One of the easiest ways to spot a ZF is ribbed crisscross pattern on the sides. The transmission is aluminum and has an integral bell housing (one piece with the transmission) with a top mounted shift tower. Look for PTO cover plates on both the driver's and passenger's side. Weight is approximately 175 lbs.
Adapter required?
The ZF integral bell housing will bolt directly to your stock 8 cyl engine, but requires an adapter between the transmission and transfer case, replacing your 8 cylinder intermediate housing. A new spud shaft for the transfer case is also required and is part of most adapter kits.
The super low first and overdrive 5th gear make this one of the few transmissions that has the best of both worlds. The combination allows you to have comfortable highway speeds and still be geared to handle the tough trails. The ZF originally came stock in ¾ ton and larger trucks making it a very heavy duty transmission. The fact that it's a fully synchronized newer transmission also means it's easier to find, shifts smoother and is more efficient.
Installation is fairly complicated, requiring some custom fabrication and may be out of the range of some shade tree mechanics. Under dash air conditioning is very difficult because the shifter handle is so tight to the underside of the dash.
Cost: (Approximate)
Transmission: $800 used and $1000-1500 rebuilt Adapter (with spud shaft) $475-525 New drive shaft $150-200
Bell housing:
Standard Ford. Will bolt up to small block (289-302-351) engines.
Modifications needed:
The swap requires a custom fabricated cross member and transfer case shifter brackets. It also requires a hydraulic clutch due to the integral bell housing, although the stock Bronco clutch and flywheel are retained. The overall length is longer than stock requiring a shorter drive shaft. Because of the top shifter a hole needs to be cut in the top of the transmission tunnel.

Manual Transmissions1st2nd3rd4th5th
Bronco 3 spd (6 cyl)3.411.861.00
Bronco 3 spd (8 cyl)2.991.751.00
NP 4356.693.341.791.00
Toploader (Close ratio)2.321.691.291.00
Toploader (Wide ratio)2.781.931.351.00
Toploader (Overdrive)3.291.841.000.81
NV4500 (Dodge)5.613.041.671.000.73
Automatic Transmissions1st2nd3rd4th5th
Bronco C42.461.461.00
AOD w/ low gear set2.841.551.00.67