Internal Differences - ZF5 S-42 and S-47?

[bulletpruf]

Fellas - I understand the S42 is rated for 420 ft/lbs and the S47 is rated for 470 ft/lbs, but does anyone know what the internal differences are? Are all internal parts interchangeable? Did a search and didn't find the info that I was looking for.

Reason I ask - I just disassembled the 1996 S47 4x4 trans that I'm going to use to convert my '87 F350 CC DRW truck to 4x4. I have the original S47 2WD trans from the truck, too, and I'm wondering what S42 parts I can swap in if they look better than the S47 parts - case, countershaft, mainshaft, etc.

On a related note, does anyone know what components were changed to get the torque rating from 420 ft/lbs to 470 ft lbs?

Thanks!

Scott

 

[u2slow]

I do know the gear ratios themselves changed. That's probably going to limit what parts can work together.

 

[ROCK HARVEY]

I know they changed the case casting to strengthen it and reduce cracking, I think that has a lot to do with the higher torque rating.

 

[bulletpruf]

Thanks for the input. I appreciate it.

 

[jcksnghst]

Can a zf5-47 front case be used on a zf5-42?

 

[Rdnck84_03]

I think I have heard there was something different with the input shaft length or possibly the bellhousing length. Something to do with the shaft not reaching into the pilot bearing when swapped. Supposedly one will interchange with the other, but they can't be swapped the other way.

I have no personal experience with the differences as I have never compared them. Or if there is any truth to it, but may be worth looking into before jumping in.

James

 

[jcksnghst]

Or if there is any truth to it, but may be worth looking into before jumping in.

Too late... My s42 case busted and I found an s47 case that I have installed only to have a severe whine in all but 4th gear.... Ugh
And the worst part is I'm stranded... Yay.

 

[ROCK HARVEY]

@jcksnghst what state are you in?

 

[KansasIDI]

My buddy has a 1988 F350 CCLB 2WD dually with 7.3 IDI that he put a S5-47 in. He didn’t have any issues, bolted up and shaft length was the same

 

[bulletpruf]

Too late... My s42 case busted and I found an s47 case that I have installed only to have a severe whine in all but 4th gear.... Ugh
And the worst part is I'm stranded... Yay.

I have the complete internals from an S47 trans - it was behind a 460. No case. I'm in San Antonio, TX.

The shift rails are longer on the S47, so you can't fit S47 rails in an S42 case unless you shorten them.

 

[IDIBRONCO]

My buddy has a 1988 F350 CCLB 2WD dually with 7.3 IDI that he put a S5-47 in.

Man, you sure do keep good company. I'm glad to see some younger people getting in on the IDI powered trucks.

 

[KansasIDI]

Bunch of us around here who like em. Really gettin to be more of us…

 

[Austin86250]

Man, you sure do keep good company. I'm glad to see some younger people getting in on the IDI powered trucks.

I bought my first idi at 15 2 years later still got it and have had 3 idis parts trucks sense and I’ve gotten 3 of my similar aged friends to daily idis aswell

 

[jcksnghst]

@jcksnghst what state are you in?

Georgia