Ford ZF Transmissions & Parts
In late 1987, Ford introduced the 5speed ZF transmission in the F250, F350, & F450 trucks.
They were available for gas as well as diesel models. The easiest way to identify the unit is to see that it has power take off (pto) opening plates on the lower sides of the unit. ZF transmissions are reliable units that should provide good service when taken care of properly. Keep in mind that the ZF has 6 constant mesh mainshaft gears, so there is a considerable amount of potential for heat buildup. It is never a good idea to leave the truck idling with a pto engaged, such as in tow truck applications. The unit was redesigned in ’96 and had small, but significant changes. The synchro teeth were enlarged to provide longer life and more positive shifts, and the bearing retainer was designed to be replaced without having to disassemble the case. The case was beefed up also with this design.
These units are prone to be a little noisy, and noise issues comprise most of the complaints we hear. Please do not remove your transmission if noise is a problem. Check all the components of your drivetrain carefully first. Things like injectors, dual mass flywheels, or even differential problems can cause a noise to come through the unit. Before we tear a unit down with a noise complaint, we make sure that we have done our best to eliminate the possibility of something else as a the source of the noise.
The ZF6 is a heavy-duty, fully-synchronized, constant-mesh 6-speed manual transmission.
There are a few variances of the ZF6
Ford has been using the ZF6 since the late 1990s. Ford’s configuration uses a unique internal oil pump to pump lubricating oil to an external oil cooler, much like that of an automatic transmission, to dissipate the heat generated during heavy-duty use or towing. It also uses a different input bearing. The Ford ZF5 and ZF6 line uses a tapered input bearing for added strength.
General Motors used the ZF6 transmission in the 1989-1996 Corvette. They started using them again in 2001 mated to their 8100 Vortec and the Isuzu Duramax engines. GM modified theirs to accommodate for the complaints Ford had with theirs. A large complaint was the noise produced. They added a bushing to metal rail socket for the shifter stub. They gave the shifter a “longer” throw for a more firm feel. They also added more angle to the helical gearsets to aid in reducing noise. GM models do not use an external oil cooler. Instead, they opted for allowing the transmission to operate at a higher temperature, then specified the use of synthetic oil, which will tolerate higher temperatures than conventional oil and is expected to last the life of the vehicle without oil changes.
If you have determined that a transmission is needed, we can help. We can rebuild your unit or sell you a reman from our stock. To get the right transmission, we will need ALL the numbers from the tag on the side. If the tag is missing, we will need all vehicle info including VIN to get you the right unit. The core MUST be completely assembled & have the shifter stub still on it. Shipping & handling can be quoted with a zip code and is normally about $175.00 in the 48 states.
We also sell a wide range of parts for the ZF, so if you decide to tackle one of these beasts yourself, let us have the parts list & we’ll get right on a quote for you. If you need more info, call us at 1.800.783.8726, or email us.
We can usually rebuild your transmission for less than exchanging it. All of our new and rebuilt transmissions carry a 12mo/12,000 mile warranty. Send us your transmission, transfer case, or differential & we'll disassemble, clean & inspect it. Next, we'll contact you with an exact price to repair the unit, including all parts and labor. After you approve the work, we can usually complete the repairs in 3-4 business days.