Bronco Forum - Full Size Ford Bronco Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
94 Posts
Discussion Starter · #1 ·
I sent in a ZF5 transmission for inspection and potential rebuild and am left completely astounded and confused. I can recover most if not all of the money I have spent up until this point, so I'm hoping that I could get some input from those who know more than myself.

For background, I intend to install the ZF5 into a 1984 Bronco with a Dana 44 and 9" rear at 4.88 final drive on 35s. The engine is a 351W (carb) currently mated to a T-18. I won't bore you with the backstory on the ZF5, but let's just say it was of unknown origin.

Once opened, it was determined that the innards and the carrier housing were from an S5-42 and the case was a relatively new S5-47 case. Theoretically, at some point someone had bought a new 47 case and stuck a 42 inside it! According to the shop who looked at it, the conversion to the new case can be done successfully and had been done correctly. He said that it needs some parts and a little work but could easily be refurbished into "as new" condition with a warranty for about $1200. If he did that, the finished product would fit on whatever a S5-47 would bolt onto. Also, I could select the gear ratio so I could have either 47 or 42 ratios.

Then, the shop owner, who is self-admittedly not a Ford expert, said that he was concerned that the finished product would not bolt up to my 84 engine, because, as he put it, the cases for the 42 and 47 take different number of bolts for the starter. According to his info one is a 2 bolt starter and the other is a 3 bolt starter and the 47 case will only work on later engines. Also, the 47 case is slightly longer with a different input shaft length to compensate.

I do not want to proceed with refurbishing the ZF5 that I have unless I can be completely certain that it will bolt up to my Windsor. The 47 is the stronger case, so if I have a choice I'd rather have the 47 case (like the one I have), but are there differences in the S5-42 and S5-47 that would make one of them incompatible with my Bronco? What is the story behind starter bolts and versions of the ZF5? Is there any difference in the carrier cover or how the transfer case attaches? Which had the better gearing to pair with a more aggressive final drive ratio?

@BigBlue 94 I've seen your comments going back quite a bit saying, to paraphrase, S5-42, S5-47 and M5OD are all interchangeable when it comes to pairing with the engine. I'm really hoping you'll weigh in on the Frankenstein 42/47 and what you'd do with it if you were me. Boom or bust?
 

·
Registered
78 Custom 460 NP435 NP205 Sniper EFI HyperSpark Ignition 4.56 Gears Front/Rear Grizzly Lockers
Joined
·
3,441 Posts
Not of much help will come from me, but every "windsor" (302/351) starter I've seen has been a two bolt starter. That goes for the old style and for the PMGR starters. There is a difference between automatic and manual as far as the starters go (how far the bendix gear kicks out), but they both only have 2 bolts.
 

·
Premium Member
84 Bronco, 351w, c6, custom doubler, np208, 5.13’s, TTB44, 9”, locked f/r
Joined
·
1,298 Posts
It sounds like your shop guy is getting info about diesel zf’s vs gas zf’s. As long as it came off a small block (4.9,5.0,5.8), you will be fine to use it in your bronco
 

·
Registered
Joined
·
1,781 Posts
Ok I am not sure but I don't think ZF built any S5-47 for the 4.9, 5.0, and 5.8 engine group. S5-47 were built for 460 and diesel engines. So if it is a S5-47 case it will not bolt up to the small block engines.
 

·
Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
Joined
·
16,367 Posts
Ok I am not sure but I don't think ZF built any S5-47 for the 4.9, 5.0, and 5.8 engine group. S5-47 were built for 460 and diesel engines. So if it is a S5-47 case it will not bolt up to the small block engines.
You are mistaken. I have an S5-47 from a 96 F250 supercab with 351w on my shelf.

As said there is no difference in mounting for and smallblock bellhousing ZF5, whether 42 or 47. As long as it is an internal clutch from a small block or 300 it will work

Proceed with the rebuild!
 

·
Registered
Joined
·
1,781 Posts
Yep I was wrong I checked the sheet this morning. Here is the progression of part numbers both Ford and ZF. You can use this to compared to the part numbers of the case you have to verify that it is for small block. They did offer the S5-47 for MOD motors too. It was listed as S5-47M. Page 3
 

·
Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
Joined
·
16,367 Posts
Yep I was wrong I checked the sheet this morning. Here is the progression of part numbers both Ford and ZF. You can use this to compared to the part numbers of the case you have to verify that it is for small block. They did offer the S5-47 for MOD motors too. It was listed as S5-47M. Page 3
Yep the ZF5-47 came behind mod motors and diesels until about 05? When the ZF6 was introduced. I have an 08 with a ZF6 behind a 5.4L V8. The six is leaps and bounds ahead of the zf5: extra reduction gear, granny and OD, short shifts with positive engagement, and beefier internals with a fluid cooler.

What is rarely mentioned is that the SBF and MOD bellhousings are the same shape and size with the same mounting holes. However, the locating dowels and a pair of bolts have had their positions swapped. It is possible to put a ZF6 behind a smallblock. I really want one behind my 300.
 

·
Premium Member
84 Bronco, 351w, c6, custom doubler, np208, 5.13’s, TTB44, 9”, locked f/r
Joined
·
1,298 Posts
Yep the ZF5-47 came behind mod motors and diesels until about 05? When the ZF6 was introduced. I have an 08 with a ZF6 behind a 5.4L V8. The six is leaps and bounds ahead of the zf5: extra reduction gear, granny and OD, short shifts with positive engagement, and beefier internals with a fluid cooler.

What is rarely mentioned is that the SBF and MOD bellhousings are the same shape and size with the same mounting holes. However, the locating dowels and a pair of bolts have had their positions swapped. It is possible to put a ZF6 behind a smallblock. I really want one behind my 300.
It was 99 when they switched to the zf6.
The trans changeover in 05 was on the autos, when they went from 4r100 to 5r110. At least as far as diesels are concerned
 

·
Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
Joined
·
16,367 Posts
It was 99 when they switched to the zf6.
The trans changeover in 05 was on the autos, when they went from 4r100 to 5r110. At least as far as diesels are concerned
Ive driven a 7.3 psd first gen superduty with a 5 speed manual... Was my HS girlfriends step dads truck.
 

·
USAF C-17 Maintenance
Joined
·
7,001 Posts
It was 99 when they switched to the zf6.
The trans changeover in 05 was on the autos, when they went from 4r100 to 5r110. At least as far as diesels are concerned
You could get the five speed up 'till '01 with the six speed being an option. Six speed standard in '02.

Adrianspeeder
 

·
Premium Member
84 Bronco, 351w, c6, custom doubler, np208, 5.13’s, TTB44, 9”, locked f/r
Joined
·
1,298 Posts
Interesting. Only ZF5 Super Duty’s I’ve ever seen were “early 99” (98 build date) trucks
 

·
Registered
Joined
·
1,781 Posts
Search as I might I couldn't find a drawing of the Mod Motor bell housing pattern. Here is the drawing for the Small Block and a pic of the Mod Motor.

 

·
Premium Member
1981 Bronco, 4.9L, ZF5, NP208, Detroit Truetracs, 3.55 gears, 31" Wranglers front and rear
Joined
·
2,164 Posts
1 - 20 of 21 Posts
Top