Regearing a ZF5

[LCAM-01XA]

The idea is to end up with a creeper-gear diesel transmission and a close-ratio gasser. Factory configurations are just the opposite. The diesel is the work horse and absolutely positively needs a low 1st, the gasser would be the go-fast toy and for it gears that are closer together would work better. The diesel uses 1-1/4" input shaft, same as a 460, while small blocks run 1-1/16" shafts. Is the difference in shaft diameters consistent throughout the length of the shafts? In other words can the gears from the 1-1/16" small-block shaft be used with the 1-1/4" diesel shaft and vice versa? Or do we need a 460 truck due to its 1-1/4" shaft matching the diesel size? Engine size (351 or 460) of toy truck is all the same as far as intended use goes, gears compatibility with the diesel trans will be the deciding factor.

Also it seems the diesel ZF5 we'll start with will be a 2wd model, thus the toy-truck needs to be a 4x4. Are tailshaft housings and output shafts easy enough to swap around? TTB of toy truck will be ripped out in favor of some long-travel 2wd twin beams anyways, so no loss of functionality there...

There is someone on the east coast (NJ or Philly or somewhere) who every once in a while drops such a conversion on CL, but they were unwilling to answer questions regarding technical details as from what I understand this is part of their business activities.

Thanks!

 

[laserjock]

If you go over to the tech articles and find the ZF information for the world thread, the link takes you to ZF. If you scroll all the way to the bottom of the page, there are parts catalogs for the ZF transmissions Ford used. Says there are exploded views. I am probably not savy enough to compare but you probably are. They might be able to answer some of your questions. I don't know how, but it would probably be a good idea for someone to download the manuals and put them in a repository here somewhere because links get broken and things move around sometimes.

Hope that helps.

 

[BrandonMag]

Intricate knowledge of all the ZF minutiae is not my forte, but it is my understanding that the tailshaft from a 2wd ZF is not compatible with a tailshaft from 4wd ZF. That is, you can't just bolt a 4X4 ZF tailshaft on to a 4X2 ZF and vice versa.
You can, however, bolt a 4X4 tailshaft on to a 2wd F-SuperDuty ZF. The parking brake on the SuperDuty ZF takes place of the transfer case.
Hope this helps.

 

[Bashby]

Do you know that you can redrill the bell housing on a 460 trans and bolt it to a diesel?

 

[LCAM-01XA]

Laser, I actually have that PDF, the 78-page service manual, right? But again diagrams only show so much, like for example while both small-block and diesel transmission come apart the same way there is no mention whether stuff attached to the input shafts will interchange from one shaft to the other. Guess we should start writing part numbers down... Something interesting in that document, it says wide-ratios were available for ALL engines (diesels included?) in trucks over 8500 GVW, except the F-Superduty with the diesel which always got the close-ratio. The close-ratio was available for all light-duty F-series with the diesel. That leaves me with the impression there are, at least in theory, some diesels out there that got the wide-ratio. Tho we're yet to see one, ever!

Brandon, do you mean a tail shaft or a tail housing? I know the 4x4 tail housing won't work with the 2wd shaft and the other way around, it kinda appears that what will be swapped instead are the cases, as in the whole geartrain remains with its respective tail, they just get dropped into the opposite front case. Also as far as i'm aware the F-Superduty transmission requires no internal work to be made into a 4x4 unit, just pull the drum brake and slide a t-case on.

Bashby, yes we are aware of that. However the diesel trans is nearly free (well, a favor is needed), and we were hoping to end up with two transmissions after all of this... Tho you are right, the path of least resistance would be to get a 4x4 460 toy truck and then take its ZF out and swap cases with the diesel, since the input shafts are the same diameter that should be a simple bolt-on affair, no machining (the diesel bolt pattern into the 460 case) needed.

 

[laserjock]

I hate to say it but the only way you might figure this out short of just trying it is to go through part by part and compare part numbers. You might be able to piece it together that way if you can get full expanded views of enough variants. That's pretty much what I was getting at. There are actually several pdf files there. If you haven't looked in a while, it might be worth going back and making sure there is not something else that's useful.

 

[LCAM-01XA]

Yeah, I think I'll stick the boss lady on that task - I got other more pressing issues to worry about (like piecing together a front LSD with Dana and Sterling parts), and that desert runner is gonna be her project anyways But I'm pretty sure we'll go with the 460 stuff, this way she gets stupid amounts of torque to go fast without spinning the engine to the moon, and I don't have to get creative with machining for bolt patterns and what not, just swap cases and go.

 

[BrandonMag]

Whoops, my bad. I meant tail housing.

 

[LCAM-01XA]

No biggie, I got what you meant to say.

 

[Sir AxleRod]

If the gasser ZF-6 had the granny range my NP435 does, I'd be re-gearing to run one, and spend the $ on it.

Only moderately impressed witht e ZF-5, but the 6 I put in my Expedition, that is a gift of the Gods, I'm hear to tell ya.

 

[LCAM-01XA]

If the gasser ZF-6 had the granny range my NP435 does, I'd be re-gearing to run one, and spend the $ on it.

Only moderately impressed witht e ZF-5, but the 6 I put in my Expedition, that is a gift of the Gods, I'm hear to tell ya.

Currently running a 435 as well and not willing to give up that low 1st, with 3.55s it's the only way to get things moving under load. We got the gears to switch to 4.10s for more pulling power if a diesel ZF5 is to be used, but there's no point in that - truck runs either empty or darn near overloaded, empty the 3.55s + OD is sweet for MPG and at full load even with the 4.10s the engine doesn't make enough power to continuously stay in OD anyways. If any decent money is to be spent on the diesel it would be on a Ranger aux box, not a ZF6. Heck if we had the wheelbase I'd much rather go 610 or 6610 with a divorced 205 and be done with it once and for all. TBH the ZF5 swap would be only for MPG purposes and only cause it's cheap enough that it will pay for itself in one season, personally I hate how they feel and shift but I can deal with it if it enables more and longer trips out. The other truck we'll be building, well that pretty much needs a ZF5 cause of desired top speed, not touching an auto there.

 

[79jasper]

^ exactly.
Eventually I'm dumping the zf5 in my powerstroke for a 4r100 or maybe a zf6.

Sent from my SM-T537R4 using Tapatalk

 

[LCAM-01XA]

Jasper, what gear ratios does your Stroke have? Should be on the label on the side of the trans. Supposedly a wide-ratio was available with the PSD engines unless it's F-Superduty, but those don't really need wide ratio to get moving cause of their low gears in the axles, and once moving close ratio is better to keep moving at good pace. Interesting what transmission gearing Ford decided a cab-chassis 1-ton needs...

 

[79jasper]

Well I'm not on the original zf5. Lol
The one I have came out of the 88 I had, which also wasn't the original to the 88, as it came auto. But I can check the tag.
I have actually felt a difference between the two trans.
Axles are 4.10's.

Sent from my SM-T537R4 using Tapatalk

 

[LCAM-01XA]

We're on transmission #3 on this truck, at least, likely #4. Went like so: factory E4 -> beefed up E4 -> close ratio T19 -> NP435. Switched out more out of convenience then necessity.