OT ZF-5 trans question

[fireguywtc]

I am curious if the ZF-5 trans will bolt directly up to all the 385 series motors without adaptation. I am sure I will have to adapt all the clutch stuff, but did the bolt pattern or anything like that change throughout the years? For instance would the ZF trans bolt up to a 60's or 70s 460/429?

I found a ZF-5 trans for sale on craigslist for $300 and before I start looking into it more I want to see if it will fit the older 385 series motors. TIA

Edit: I realize there were ZF-5 trans for other engines, but I am only curious about the 385 series trans, I know the others wouldn't fit.

[averagef250]

The bolt pattern is the same, the input shaft stickout and pilot diameter is the same. The only real difference is the 460 ZF has a 1 1/4" 10 spline input shaft instead of the 1 1/16" input all the old stuff had. You will have to run a clutch and pressure plate that will work with that. The late model 460 flywheels are external balance, but you could take one and have it internal balanced to work on a pre-79 460.

Also, if you wanted it to be a 100% instant bolt up deal you can drop in a 1 1/16" 10 spline input from a small block/six ZF 5 speed.

[fireguywtc]

Thanks Dustin. Forgive my ignorance but what is the difference between and internal vs. external balanced flywheel? It sounds like the older external flywheel can be changed into an interal balanced one if I read your post correctly. If thats the case it sounds like an easy fix. Can a newer internal balance flywheel bolt up to pre 79 460?

It seems to me the easiest route to go as far as adaptation is to just order a newer clutch and pressure plate for the larger shaft since it is unlikely I am going to find just the input shaft from a small block ZF 5 without buying the whole trans.

Lastly is the only way to actuate a clutch with a hydraulic type clutch or is there a mechanical setup that I don't know about?

These are all ideas I am trying to get together for the 67 as I contemplate my future engine/trans combo.

Thanks again!

[averagef250]

Bill, The 79 and newer engines were external balance meaning they have an extra cast in weight in the flywheel. This weight will need machined off and the flywheel balanced for nuetral balance to be used on the older engines. It's probably easier to try finding a pressure plate and clutch that will fit an older style flywheel.

I can't help any more than that with those details. I've never done it myself.

The 460 ZF's use an external hydraulic slave, but they have a clutch release fork. You might be able to adapt that fork to the old mechanical linkage or you may have to go to hydraulic with everything. I can't tell you for sure.

[fireguywtc]

Thanks again Dustin! I am going to look into this more but it sounds like its definetly doable.

I was looking over Jamie's (Rancher50) thread and noticed he has the ZF behind the 6.9. It seemed his only real issue was the clearance of the bell housing and the cab, but I am not sure if it was caused by the size of the tranny or if the engine made it sit higher. Other then that it looked like it sat nicely in the frame and looked to be very close to the stock cross member location. I see he also had adapted a hydraulic clutch for his setup as well. I don't have a preference one way or the other, I just wasn't sure if there was different types of clutches over the years.

[hydropower]

I put a zf 5speed behind a 460 in my 78 f250 4x4. Best mod I have ever done. You will like it

[fireguywtc]

Hydropower, I just purchased a 460 and my vision of having a 460 with a zf5 is coming to fruition. I need to know all I can learn from your swap since I am sure there are some complications. Some I can already forsee is speedo, hydraulic clutch setup, and crossmember mounting. I hope you can help me out. Thanks, Bill

[tiresmoke123]

I am in the midst of the same dilema on my '79 F 250. I got an internally balanced 460 and a 2wd ZF5. I thought I could easily replace the tailshaft to make it a 4x4, but no such luck. I had gotten a small block 4x4 ZF trans but ended up putting the whole gear pack in my big block case. To do this I had to use the big block input shaft and the big block center shift rail. The small block trans has a longer bellhousing and therefore the input shaft is longer. The shift rail is also at a different location in relation to the gear pack from big block to small block. I just got the trans back together and it shifts well (out of the truck). For a flywheel I was told a 390 (FE) flywheel would work because it is a neutral balance flywheel, but you will either have to use a pressure plate for the FE, or get the flywheel machined for the ZF pressure plate. I am having trouble finding just a clutch disk, so I may end up having my flywheel machined, but I am not sure yet. I also can not find the correct size pilot bearing/bushing. I am probably going to have to get one a little oversize and have it cut to what I need. I did just see that someone used a pilot for an 85, I haven't checked that out yet either. By the way, I am keeping my '79's orriginal 205 transfer case. I had read in another forum that the ZF trans ends up being the same length as the orriginal and the t- case will bolt right up (which it does). Therefore the driveshafts will all work out with no mods. I am also keeping my mechanical clutch linkage. The ZF fork needs to be cut and welded to the fork that is orriginal to your truck. You will have to determine length and fabricate accordingly. The mount for the slave cylinder may need to be cut off for clearance, but I am not sure (not that far yet). You may also have to cut a notch in the rear flange on the ZF where the transfer case shift rod goes. I have to do this on mine, but I don't know how your t-case is. I hope this helps. If I come up with more solutions as I go, I will post them.
I was told that the difference in the early (87 to 93?) and the late (93-96?) ZF trannys is the gear ratio spread. The early ones have more of a creaper gear for first, and a wider jump between gears than the later ones do?.

[averagef250]

I am in the midst of the same dilema on my '79 F 250. I got an internally balanced 460 and a 2wd ZF5. I thought I could easily replace the tailshaft to make it a 4x4, but no such luck. I had gotten a small block 4x4 ZF trans but ended up putting the whole gear pack in my big block case. To do this I had to use the big block input shaft and the big block center shift rail. The small block trans has a longer bellhousing and therefore the input shaft is longer. The shift rail is also at a different location in relation to the gear pack from big block to small block. I just got the trans back together and it shifts well (out of the truck). For a flywheel I was told a 390 (FE) flywheel would work because it is a neutral balance flywheel, but you will either have to use a pressure plate for the FE, or get the flywheel machined for the ZF pressure plate. I am having trouble finding just a clutch disk, so I may end up having my flywheel machined, but I am not sure yet. I also can not find the correct size pilot bearing/bushing. I am probably going to have to get one a little oversize and have it cut to what I need. I did just see that someone used a pilot for an 85, I haven't checked that out yet either. By the way, I am keeping my '79's orriginal 205 transfer case. I had read in another forum that the ZF trans ends up being the same length as the orriginal and the t- case will bolt right up (which it does). Therefore the driveshafts will all work out with no mods. I am also keeping my mechanical clutch linkage. The ZF fork needs to be cut and welded to the fork that is orriginal to your truck. You will have to determine length and fabricate accordingly. The mount for the slave cylinder may need to be cut off for clearance, but I am not sure (not that far yet). You may also have to cut a notch in the rear flange on the ZF where the transfer case shift rod goes. I have to do this on mine, but I don't know how your t-case is. I hope this helps. If I come up with more solutions as I go, I will post them.
I was told that the difference in the early (87 to 93?) and the late (93-96?) ZF trannys is the gear ratio spread. The early ones have more of a creaper gear for first, and a wider jump between gears than the later ones do?.

Ford pilot size is 17MM. There was no change from the 60's through 2012. Many Ford cranks will accept a 6303 ball bearing instead of the crappy bushing/needle bearing assembly.

There are 42 and 47 series ZF 5 speeds. The 47 didn't come about until 95 or so. The ratios are the same for 42 and 47 series ZF's from the same application. Gas ZF's are wide ratio with granny gear. Diesel ZF's are close ratio without granny.

I'm amazed how many people have driven these trucks for hundreds of thousands of miles and don't know they don't have a granny gear. Most of the old Ford diesels came with 4.10's with the 4:1 first gear ZF. They should have had 3.54's then the gear changes would actually feel right.

Many people confuse the Mazda M5R2 with the ZF in the light duty F-250's and since these are close ratio that might be where so much of the bad ZF ratio information comes from.

[tiresmoke123]

Thanks for the info on the piot bearing and clarification on the ZF ratios. I will be looking for a 6303 bearing tomorrow.
I put the 390 flywheel on my 460 today and all bolt holes line right up. I am going to call centerforce tomorrow and see if I can get a custom combination of disk and pressure plate to solve the issue of having the flywheel redrilled for the ZF pressure plate. I'll let you know what I end up doing.