NP540 query

[Aaron S]

I am looking into installing an NP540 into my 68 W300. I know there have been many threads relating to this transmission but there are a couple of things I am curious about that I have not seen covered in them.

I understand that it should bolt right onto my hydraulic bellhousing, and will require a different clutch because of a larger input shaft/different spline count. This sounds like I will also need a larger throwout bearing, yes? Will I also need a larger clutch fork to actuate it? If so, do these parts exist in a retail environment and are there any reference numbers for them?

I have contacted a couple of heavy truck parts houses about this transmission. It seems that there are a few out there but they would like an input shaft number to determine which one I need. Do any of you guys who have messed with these trannys know what input shaft I should be looking for?

I am looking at the NP540 because it is a fairly easy swap (I have heard) and I would very much like to have another synchronized gear in my truck. That being said, I am not dead set on this particular transmission. I understand there may be any number of Clarks and possibly some Spicers that would work here as well, and I am open to suggestions. That being said, I am not necessarily looking for an overdrive and I really don't want to use a modern transmission. Most modern five or six speeds appear to be too long to fit easily without relocating the transfer case or changing to a modern, married unit. However, the whole reason I am posting this here is the very high probability that a good many of you know something I don't, and I would be happy to learn from your experiences.

[712edf]

What transmission do you currently have, the NP435 4-speed?

I do not know if the clutch fork changes when going from one trans to another. I do know there are more than one size of T/O bearing and the front bearing retainers aren't all the same either diameter/length.

Do you already have a NP540?

HR clutch will have whatever clutch disk you need. Possibly the T/O too.

Bucky

[Aaron S]

Yes, the NP435 is what I currently have. No, I have not yet acquired an NP540. I have had no luck finding one in any of the area truck salvage yards, most of their trucks of that era having been crushed in the last eight years or so because scrap prices were high and the parts were not in high demand. So the likelihood of finding one "complete" with the bellhousing and clutch fork assembly still intact (which would be ideal) currently seems rather slim. Some parts houses have them, but they are sitting on shelves to be only identified by various numbers with secret, arcane meanings known only to the initiated.

The big parts seem fairly easy, I am trying to learn about the frustrating, small parts that will be required to make this work before I dive in over my head. Perhaps I am being overly cautious, but the phrase,"The Devil's in the details." comes to mind.

Thanks for the tip on HR clutch, that information should prove useful.

[712edf]

Where in Texas are you? I have an extra NP540 with the T/O, pressure plate, clutch disk & fork.

Flywheel & bellhousing are still in the truck attached to the poly 318.

Bucky

[Aaron S]

I am in Kerrville. If you would be willing to sell those parts I would be thrilled to purchase them from you... I'm not sure when I could make it up there to get them though.

[712edf]

I am in Kerrville. If you would be willing to sell those parts I would be thrilled to purchase them from you... I'm not sure when I could make it up there to get them though.

I have no need for them. The transmission itself is in the back of my van taking up space. The other parts are in my Dad's shop at Pottsboro. The truck with the motor/bellhousing/flywheel is there as well.

If you're bell fits the 540 then I assume you don't need mine or the flywheel, that yours are the same.

Bucky

[Aaron S]

I won't need the flywheel. I would like to get the bellhousing because I am concerned about the possible difference in the clutch fork setup compared to the 435 due to the 540's larger input shaft. I am curious to set them side by side and see what's what.

Now that I think of it, it seems like we corresponded a few years ago about about me purchasing that W500 from you. I believe I determined that it was too large to fit on my trailer and so it would be too expensive for me to move... which is really too bad. I would love to have all those parts, though I've no idea what on earth I would ever do with them, other than covet them in some odd, gently rusting manner.

I would not mind coming up and wrestling the bellhousing off, though as I write this I've just remembered that requires pulling the motor because the rear mounts are on the bellhousing... ****. Anyway, I'm sure we can work something out.

Do you have a price in mind?

[Gordon Maney]

I would love to have all those parts, though I've no idea what on earth I would ever do with them, other than covet them in some odd, gently rusting manner.

This is what we do.

I have an SAE bellhousing for a big block.

[712edf]

I won't need the flywheel. I would like to get the bellhousing because I am concerned about the possible difference in the clutch fork setup compared to the 435 due to the 540's larger input shaft. I am curious to set them side by side and see what's what.

Now that I think of it, it seems like we corresponded a few years ago about about me purchasing that W500 from you. I believe I determined that it was too large to fit on my trailer and so it would be too expensive for me to move... which is really too bad. I would love to have all those parts, though I've no idea what on earth I would ever do with them, other than covet them in some odd, gently rusting manner.

I would not mind coming up and wrestling the bellhousing off, though as I write this I've just remembered that requires pulling the motor because the rear mounts are on the bellhousing... ****. Anyway, I'm sure we can work something out.

Do you have a price in mind?

Yes we did correspond about the W500. And yes the bell acts as the rear mount, so the engine would need pulling. I never got around to it because of the height (and I got married last July. Married life takes up a lot of time). It might be easier now, as I have removed the driver's side fender. If I had the front core/passenger fender off then my hoist could work.

Not sure on a price, but definitely don't need the parts so I will work with you.
Could you (or anyone on the forum) put up pictures of the bell/fork set-up on a NP435 truck (pre-69)? I don't have pictures of my parts, but could have my dad measure them or maybe send me pics via phone.

Bucky

[Aaron S]

I don't have the transmission here at the house, but I will try to get some pictures of it next week. It would certainly be convenient if I could use that transmission with the junk I've already got.

I have an SAE bellhousing for a big block.

What a fascinating thing to have. Do you know what it came out of? I assume it would be from a heavy truck or possibly a piece of heavy machinery. I have heard tell of an old Gradall around here somewhere with an industrial 413 and a five speed.

[712edf]

The SAE bell that Gordon has likely bolted an industrial 413 to a Clark or Spicer transmission.

The big trucks used a variety of stuff compared to the 100/200/300 pick-ups.

Bucky

[john eickhof]

Np-540/541

In my experience, I have swapped several 435s with 540/541s in W300s, we never had any problem with clutch plate, TO brgs or forks and bell housings, however, the transmissions we acquired came out of Dodge vehicles (1965-71) They just dropped right in, Be sure you are getting an OD model! Otherwise it will be a DD model and you won't gain anything except another mid gear, The trans type is typically listed on the VIN/Equipt ID plate, the best source is a Dodge school bus as the OD (Overdrive) trans was preferred over a 2 speed rear axle for ease of driving. Good luck!