ZF-S5/42 vs 47

[gaspipe]

Time for a transmission swap. My 1995 has a v42 ZF5 in it now, and it's time for a rebuild.

The question is: Is it worth the effort to go with a v47, or just plan on another ~250k with the 42? My F250 is only modded with a 4" exhaust and a big intake, and I plan to stay that way. AFAIK, I've never driven a truck with a v47 transmission, but other than the slight gear ratio changes, I'm assuming it's more or less the same animal?

Thoughts?

TIA for any musings, rants or info.

[glovemeister]

s47 is rated for more torque, IIRC.

[351fifty]

47 is rated for more torque, I was under the impression only idi's had the 42 anyway, and that gearing was exact same.

[gaspipe]

Thanks Glove & 351.

Interesting....ya learn something every day....S42 rated for 420, S47 rated for 470 ft/lb. I am certain my '95 (build date is 5/95) has a ZF-S5-42 because that's what's on the plate riveted to the side of it.

Nevertheless, the v42 would appear to be plenty strong for the job at hand I think.

[glovemeister]

Sorry for not pointing out the torque numbers based on the trans name, lol looks like you figured it out.

[ol_Blue97]

the gear ratios are not the same the s42 is considered a close ratio and the s47 is a "wide ratio" in comparison. the s47 is soposed to be the smoothest to shift and is rated for the most TQ. sound like a no brainer to me

here you go..

S42 ZF5 Close Ratio
1st Gear:
4.14
2nd Gear:
2.37
3rd Gear:
1.42
4th Gear:
1.00
5th Gear:
0.77
Rev Gear:
3.79

S47 ZF5
1st Gear:
5.08
2nd Gear:
2.60
3rd Gear:
1.53
4th Gear:
1.00
5th Gear:
0.77
Rev Gear:
4.66

[351fifty]

Hell a clutch can make up the torque difference lol, and overdrive is the exact same so good enough imho, just depends if you want your first couple gears to stretch out a bit, good luck either way

[gaspipe]

If I can get my hands on a rebuildable 47, I might jump on it just for the 2nd/3rd ratios. Otherwise, I'll rebuild the 42. With 4.10's it'd be nice to have a longer 5th gear for interstate cruising, but I reckon that's what a car is for

My South Bend single mass conversion clutch came today...so I'm getting itchy to tear into the transmission now and see WTF was going on with the dual mass OEM clutch that's in there.

I had no idea Ford had changed the ratios, but good to know. Thanks!!

[Turbo_pace]

The 47 seems like it's more for towing, I'd like one for my truck because first gear is lower and well I still have 3.55 in my truck.

[Hondacrf250]

I can't figure this dang site out. But I need to know if a 1993 7.3 idi S5-42 transmission will fit into a 1997 7.3 powerstroke. If not what do I need to make it work. It can't be to much different.