Anyone done a c6 to ZF5 swap on their late model 70s 4x4? [Archive] - 460 Ford Forum

: Anyone done a c6 to ZF5 swap on their late model 70s 4x4?

01-15-2012, 08:18 PM
My c6 is shot on my 79 and a buddy of mine has a ZF5 for $500 he wants to sell (including pressure plate and clutch).

On another forum talking to some folks about their swap and wondering if any of you have done it and how hard was it?

01-23-2012, 05:08 PM
Does anyone prefer a zf5? or is the np435 better?

01-23-2012, 05:56 PM
It's a fairly straight-forward swap. You'll need to brace the firewall for the clutch's master cylinder. I swapped an NP435 out for an M5R2 (Mazda-sourced 5 speed they put behind 300-6s and 302s in F150s and F250s). The '70s trucks, keep in mind, had the mechanical clutch setup with the rod that went through the floorboard/firewall down to the Z-bar that mounted between the engine block and frame. The ZF (and M5R) trucks had a hydraulic clutch setup which stresses the firewall. Which side of the firewall you wish to brace is up to you. For aesthetic purposes, I simply welded a big plate on the inside firewall (you don't see it buried behind the dash and from the engine side you don't see anything). I simply ground down the weld on the clutch pedal rod where the "arm" that pushes on the rod attaches. I rotated that arm (to where it pushes a rod forward - through the front of the firewall - instead of pushing the factory rod down through the floor like the factory mechanical setup had it), rewelded it, drew a point on the firewall where the rod needed to go through, drilled that, then mounted the master cylinder appropriately and drilled the firewall for the MC fastening hardware.

Your 205 or whatever transfer case you're running will bolt right up. You might have to move/mod the trans/t-case crossmember and get your driveshafts lengthened or shortened.

I'm not particularly a fan of ZF transmissions. For sake of being an easy swap (they came in '80s and '90s Fords and are pretty-much a bolt in deal), they make sense but they are a problematic unit. They have the benefit of overdrive as well as the deep low gear, but if I were looking for a heavy duty application and needed an overdrive, I'd more likely swap in an NV4500.

I swapped in the M5R in my '78 because it still has a 300 in it.

The dumbest thing about both units (M5 and the ZF) is the abortion that is the annular slave cylinder. When that thing goes, you're pulling the entire unit instead of simply unbolting an external slave cylinder, replacing it with a new one, bleeding it and getting on down the road. With the annular unit, you're doing a complete R&R on the trans and transfer case assembly(ies).

If you don't have to have overdrive, I'd sooner go with an NP435. They're tougher. Period.

01-23-2012, 08:10 PM
Doesn't a 460 ZF use an external slave?

01-23-2012, 08:53 PM
What's problematic with the zf's? I've never seen a broken one except for one that was towed with d shaft attached.

I live in Canada hard to find modern stick trucks, we like our auto's up here :D

01-24-2012, 01:04 PM
What's problematic with the zf's? I've never seen a broken one except for one that was towed with d shaft attached.

I live in Canada hard to find modern stick trucks, we like our auto's up here :D

Generally the bearings in the earlier models 5S-42s make a lot of noise and don't last. Particularly in high torque applications (diesels and behind a good running bigblock). The late model units (5S-47s...came in the '95-'97) are a little more robust. IF I were to be in the market to do a swap, I'd try to find a 5S-47.

SOME of the early (like '88-'89) ZF 5S-42 units were exteneral slave cylinder. Those are pretty rare. The overwhelming majority have that stupid annular slave cylinder setup.

01-24-2012, 09:33 PM
Whats required for a nv 4500 swap?

01-24-2012, 10:21 PM
I prob just do a NP435 swap

01-25-2012, 08:29 AM

01-25-2012, 11:04 AM
Excuse my earlier screw up -

Most of the small-block bellhousing'ed ZFs have the annular/concentric slave cylinder whereas the big block and diesel bell'ed ZFs do, in fact, use an external slave cylinder for all year models.

Like I said, the earlier models (S5-42) are prone to being noisy and bearing failure - especially behind engines that make a fair bit of power and/or in rigs that are exposed to a lot of torque loading often (i.e. hauling a heavy load or pulling a trailer often). The late models (S5-47) are an "improved" design with thicker cases with more webbing and bigger, better bearings.

An NV4500 swap would require the requisite transmission and a bellhousing adapter and t-case adapter spud shaft and intermediate housing. Advance Adapters makes a kit to adapt a Dodge-model NV4500 (the 29 spline units they put behind 360s).

01-25-2012, 06:51 PM
This zf5 was out of mike a 1992-1996 F350 4X4

01-26-2012, 02:50 PM
This zf5 was out of mike a 1992-1996 F350 4X4

Check the tag that's riveted onto the side of the case, then. If it's dirty, just take a can of carb or brake clean and a rag to it. There should be an easily spotted rectangular area (about 1.5" tall and 3" long) on the driver's side of the case in about the middle (length-wise and height-wise) where the i.d. tag will be riveted to the case. It will be stamped with the model number. It'll indicate whether it's a 5S-42 or 5S-47.

The -42s were the earlier units (like '87-'95) and the -47s were the late model (improved/sturdier) units that were put in the '95+ trucks. I think '95 was the split year so if somebody says it's out of a '95, without seeing the tag or pulling the thing apart there's really no telling what model it is if somebody simply states it's out of a '95. The -47 is the better/more desirable unit.

01-26-2012, 07:16 PM
Thing is will they handle alot of torque and hp that a built 460 produces? I plan to build up my 466 bigger later on.

Ken Newman
01-26-2012, 08:15 PM
We've got a smallblock ZF in my son's 75 Bronco and we both have them behind our 7.3s in our '96 and '97 F250 4X4s. My 7.3 has the D66 turbo with stage II injectors. It puts out as much or more torque than 99% of the street 460s and it works fine. I don't hammer it by dropping the clutch so if that's what you have planned I can't answer that.

Rocket Doctor
01-30-2012, 01:23 PM
I've got a 5 speed ZF behind the fuel injected 460 in my 93 F250 supercab 4x4. The only noise I get out of it is at startup, and it goes away shortly after I start the truck. Honestly, it sounds more like a throwout bearing than anything in the transmission. The clutch had been replaced right before I bought the truck, and no telling what they replaced (probably nothing more than pressure plate and disc).
Anyhow, I tow a 23' Reinell with 460, and 80 gallons of fuel, or a 26' camp trailer with 60 gallon water tank, as well as a generator, tool box, jacks, chains, firewood, chainsaws, and all the stuff I need when we camp, plus 40 gallons of fuel in the tanks, in the back of the truck. First gear is plenty deep for pulling from a stop, and I appreciate the heck out of that, as my other standard transmission'd towing rigs had four speeds with granny first that in essence were three speed trans' on the road.
We just bought an 04 Super Duty F250, V10/automatic, and I'm sorta torn between which transmission I like better. Both do well disconnected from the trailers, and out exploring on the two-tracks and mountain trails, but the constant gear changes make for a sore left leg after a long day of creepy-crawling around.

01-30-2012, 05:18 PM
I just bought a NP435. :D