Hi,

It's been a while since I've been on the site, but since then I've bout myself a 2002 F-250 with the 7.3l diesel in it.

But enough about me.

I've been searching and searching and I can't figure it out.

What is physically preventing someone from theoretically swapping a 4r100 transmission to a ZF-5 speed out of an older 7.3? Aside from the obvious things (superdutys came with zf-6, different torque ratings...pcm issues..)

I'm just really curious because the 4r100 in my truck is starting to slip between 1st and 2nd gear probably because I hate automatics. And I have a zf-5 speed sitting in my garage....I am on the prowl for a zf-6 but if worst comes to worst I would like to know if it'd even be possible to use the old 5 speed in its place.

Thanks.

 

The quick answer is yes. Assuming the ZF5 is out of a diesel not some 1/2 ton gasser. The ZF6 is built a bit heavier, but I like the ratios a little bit better in the 5 since I pull fairly light...

 

The software in your PCM is not compatible.

 

Yeah that PCM....that good ole notorious PCM...I know the ZF 6 speed, although not recommended, can be run with the automatic software if a few of the wires are jumped together, so I'm sure the ZF 5 software incompatability can be over come the same way.

-The rear driveshaft would have to be lengthened and the front shortened.

-A master/slave cylinder setup + pedal would have to be fabricated (?) I know the superdutys have a twist lock setup for the master, not too sure about the slave.

-Clutch and Flywheel....is there a different balance between the OBS powerstrokes and the superdutys? If not, then I don't see why a flywheel/clutch setup from the old setup wouldn't work as long as it bolts up.

-Shifter location? Haven't had time to measure from the edge of the bellhousing to the center of the shifter but I would think they would line up in the right spot on the transmission tunnel

-The two transmissions are rated at different torques. There was an early version of the zf 6 rated at 500ft/lbs, updated to a "heavier duty
520ft/lb version. There are two versions of the zf 5 speeds, the 42 and the 47 respectfully having ratings of 420ft/lbs and 470ft/lbs.

-ZF 6 speeds have a different output spline count, where as a 4r100 has the same 31 spline count as the ZF 5.

As far as I know the bellhousing bolt patterns stayed the same from 94.5 up to 2003 for the 7.3s but I could be wrong.

 

I had an '88 Thunderbird TurboCoupe with the A4LD which was a junk tranny. I went through 2 transmissions and gave up. I went to a junk yard and found a Mercury cougar 5-speed to get my parts from. I pulled the pedal assembly (it was an assembly of all 3 pedals) which was the hardest part to get out, the drive shaft, transmission cross member, clutch master cylinder, clutch slave cylinder, shifter and shift boot (I already had a T5 sitting in my garage). I had the auto computer but in 88 the transmission was not controlled at all by the EEC so it didn't matter. The one thing I did end up with is 3.73 rear gears with a manual (manuals came with 3.55).

The install was very easy, all the knock outs were already there in the body and the holes were there for the cross member. I didn't have to fabricate anything. I can't speak for the trucks but if you can grab as much stuff as you can from a junked truck it will make things easier.

 

does anyone know if I can swap a 1994 f250 7.3 manual transmission with a 2006 f250 6.2 automatic transmission. I believe it would be a ZF5 to a 5r110w.