How much difference is there between the medium and pick up versions of the NP435? The medium has a bigger input, but are the bearings and syncros interchangeable? Any difference in the case or any of the gears?

Sam

 

I'm not sure. I can say that the 435 is probibly the biggest trans EVER install in 1/2 ton truck from the factory. hong long a trans last is most dependant upon how the vehicle is driven. It wouldn't bother me to run one in a F-600 behind a gas engine, but anything more like a diesel or a 700 serise truck and i'd go bigger.
I am told they shift much better with 15-40 oil rather than gear lube.

 

It's a heavy beast for sure- we put mine in with a couple blocks, a little ramp and a lot of muscle- never again!

I'll have to try the lighter oil- the one I have is pretty sluggish with 80/90wt.

Sam

 

I believe my '74 F250 highboy spec'd 50W oil for the tranny. It was leaking so bad for years I threw anything I had into it, mostly 80w90 gear lube. When I pulled it to replace the front and rear seals (it would just run out the front when I hit the brakes, and the back when I hit the gas), I put 50W back in it, and the 2nd syncro really REALLY liked it.

And yes, it's a beast. I had the jack fall out from under it while I was muscling it into position, thankfully, at some point in the past, I could bench-press almost 300 lbs... I was able to hold it up with one hand (input shaft was already in the clutch) and get the jack back under it Phew...

 

My tranny seeps a bit of oil, but nothing real bad. I may have to try the 50wt, my 2nd gear syncro is really grumpy with that 90wt in there! Is any harm done by running 90wt in it for the time being?

And one interesting thing I discovered- the light duty input is a direct swap for the HD one, a few guys have put the f600 trannys in their pickups by just switching out the input.

Sam

 

Interesting info...

And no, I don't think 90 weight will do anything to a 435NP. I don't think ANYthing can kill them things... The one I had in the highboy was abused beyond belief, had 350K+ miles on it (hard miles) and everything inside looked brand-new... Even the input shaft bearings...

 

the differences is the front input shaft , and some came with a brake for the F500-600 !
all internals are the same !

 

It's a tough box for sure if they ran it in the 600's and didn't change much! What size u-joints did they use in 500/600? 1410s?

Sam

 

Just a quick thread resurrection...

I found an NP435 in an F600 behind a 300 I6, and I did notice a few differences. The case is different (slightly) and it has a different bolt pattern that the pickup versions. It looks like this: http://ramchargercentral.com/index.p...ch=85668;image

Still, I'll see how much they want for it, if it's cheap I'll pick it up.

Sam

 

Cool stuff, Sam, thanks for doing this.

Just so we keep this picture, it's attached separately here, and I'm adding this to the tech folder for prosperity...

 

The spring loaded shift lever retainer cap (B8T-7220-D) has two notches, is retained to the shift tower with two pins.

This cap must be pressed down by hand and held down while turning it to remove it. People unaware use pliers or channel locks which tears out one or both of the notches.

The shift forks have nylon inserts (1/2 is different than 3/4). If these crack apart, the pieces can fall down into the gears jamming them up.

 

Have any of you used AMSOIL synthetic in the 435's? I'm going to run it in mine, they have a 50 weight that has a 500,000 mile service life. they use it in the big trucks.

 

I've got Amsoil 75w90 in my np435 and I like it, but then again, I've never come across an Amsoil product I didn't like. Let us know how you like the 50wt.

Thanks for putting this in the tech folder by the way. If I come across anymore of them in the wrecking yards I'll update this thread with more info. Part of me really wants to say there are two bellhousing patterns... I'll check into it.

Sam

 

I'm glad to see some other AMSOIL guys out there. It's great stuff. I use the spray MP (metal protector) and the heavy duty MP. Whenever I have any problem with something that need oiled I just use some MP on it. My wife is always kidding me about fixing everything with AMSOIL. Several years ago the door switches for the courtesy lights quit working on both sides of my Bird and I didn't replace them. years went by then one day after my wife kidded me about AMSOIL I went out to the Bird and popped them out and sprayed each one with MP and they both started working again and are still working today. Works great on switches and that kind of electronic stuff. Now my wife has her own can of MP. What can I say, it works. I don't sell it I use it.
If you have a squeaky fan belt spray some MP on it the squeak goes away and the belt gets conditioned with the synthetic properties of the MP. The belt won't slip (unless it is loose) and grips the pulleys better than belt dressing. Won't hurt plastic either.
Go grab some, way better than the popular brand in the blue and yellow can.
AMSOIL MP Metal Protector

 

I'm not sure if I can get it in quarts, looks like the smallest is 5 gallons for $262.00, probably a lifetime supply! I haven't checked for the capacity but I'm sure it won't hold 5 gallons.
AMSOIL SAE 50 Long-Life Synthetic Transmission Oil