Modifying An NP435 To A 5 Speed Direct Or Overdrive

[chris401]

http://classicbroncos.com/forums/showthread.php?t=96958

New to me. Has anyone swapped gears around to make a five speed? I am not worried about the whys or other ideas. Seems like a good idea if you want to keep as much as original as possible.
Thanks

[FarmMotorSports]

Having read the fourm, that quest died long ago when that particular shop in Colorado went under and took the HOW TO with them.
So what else ya got, I liked that idea.

Reminds me of the quest to flip the internals of a 205 transfer case to provide an OD and Direct, 2wd and 4wd. Very easy if you have access to all the parts to assemble in a different order Before being permanently
pressed together.

[chris401]

Well I was hoping someone here would know. In a few weeks I will talk to a man that might have done a few and will post if he has any information. It looked like it was a matter of finding the right NP donors to make it all work.

[FarmMotorSports]

Take a note pad or better still a video camera so you don't miss a single tid bit of information. There are plenty of uses for a manual transmission with more gears or OD costing less than what is available now. Plus if fits the stock location and bell housing etc...

I hope his parts combos don't include several obsolete and-or sought after transmissions for parts. It would be nice, to dump the guts out of the three speed that came in a slick, open up that NP, swap a cluster or two and (Boom) OD. And the best part is it looks like an ordinary stock slick 4speed, no adapters, cross members, length changes.

I could see that as a good side income for a guy who wanted to just market the finished products among your fellow FORD truck enthuists.

Keep us informed, hope you get all the info you need.

[chris401]

http://classicbroncos.com/forums/showthread.php?t=96958

New to me. Has anyone swapped gears around to make a five speed? I am not worried about the whys or other ideas. Seems like a good idea if you want to keep as much as original as possible.
Thanks

Unless someone post otherwise I am calling this confused information. I have talked to a few parts suppliers and the builder. None have heard of it but all said it did not seem there was any room to add the gear.

[FarmMotorSports]

My understanding is that the original builder used NP 540 series parts in a NP 435 case.

The NP 540 stuff is rare in OD form. Further more OD units have been called weak.
And there is nothing to prevent using a NP540 in a slick less than F450, size and weight may make it less desireable (around 70lbs more than the np435). I did find build threads that have used 540 series units in highboys for strength and the super low crawl gearing.

All the medium duty truck manufactures used the NP540 so they're out there, in many different ratio combinations. (At least 4 combinations I've seen listed, plus the OD combo)

[chris401]

My understanding is that the original builder used NP 540 series parts in a NP 435 case.

The NP 540 stuff is rare in OD form. Further more OD units have been called weak.
And there is nothing to prevent using a NP540 in a slick less than F450, size and weight may make it less desireable (around 70lbs more than the np435). I did find build threads that have used 540 series units in highboys for strength and the super low crawl gearing.

All the medium duty truck manufactures used the NP540 so they're out there, in many different ratio combinations. (At least 4 combinations I've seen listed, plus the OD combo)

Was it an OD only addition or could you change the whole gearing profile?

[FarmMotorSports]

What little discussion I could find would seem to indicate gear swapping between the 540 and 435 was for OD conversions only, but who knows what a gear nut with time and parts to play with could do. As pointed out in a discussion the 540 has 4 shift rails in its top cover, and uses them all, and the 435 has 3. They will not interchange so you not going to make a 5 shift 435 without magic.

Details on the OD gear swaps were vague, input shaft and cluster were mentioned as being needed, changing the input bearing, opening, and retainer.
On that same note, NP540 OD input shaft and matching cluster gear were mentioned as the parts twisting off and or cracking.

I have NO personal experience with the NP540 beyond R&R instances.
The above info is what I could find to read on New process gear and trans swaps across the web, over a few late nights.

If you have the Clark and haven't found a reason not to use it, that would be exactly where I would be headed.

[chris401]

I am keeping the original NP435 and driveshaft set aside so I may have some time to look into the 5th gear addition. The 250V has a good gear spread but is not the one I wanted. Unless I find issues in the Clark I am going to run it until I find a 282V.


QUESTION regarding a direct bolt in swap with the same driveshaft: Are a 250V and 282V the same length?
Thanks

[FarmMotorSports]

Clark 280V is 1.25" longer than 250v.

According to an Eaton interchange listing I was able to find.

[chris401]

A shorter recut I can live with. Thanks.