NP435 Trans Swap Help

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matthon

matthon

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Long story short, looking for an extended cab, short bed, automatic, non-lifted truck.
So, I bought the complete opposite, but, the bigger deal, it is rust/rot free.

Rebuilt/bored 318, dana axles, all new blah blah blah.

Only issue, NP435 trans is a little noisy in 2nd, a lot in 3rd, and quiet as can be in the rest.
It still drives along, does 80mph at 3k, just not a fan.

Is there a direct bolt in auto trans?

I keep thinking if this thing came with an auto, the rest of the driveline be the same, just can't find the answer.

Any other direct bolt in trans options?

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Cheaper to rebuild the trans that's in the truck now.
The short tail shaft 727 would be the auto the truck would have came with, but it is not a direct bolt in, there may be differences between adapter between the transfer case, the obvious stuff would also be needed, steering column, kickdown linkage etc.
 
Nice truck. A 4x4 727 is basically a direct swap. Same length and same crossmember mounts. The auto brake pedal is a direct swap for the manual brake pedal and clutch pedal, I did the opposite to my RamCharger… 727 to np435, and now TR4050!
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What year do you have there? It’s a nice find, especially being a 3/4 ton. But as stated, a 727 setup for a married transfer case/transmission should be the correct setup.
 
1984
The cab/front clip has the VIN on the dash, door jamb, under bottom of hood, and it's from a rust free 2WD automatic 1/2 ton, according to the VIN, and iirc the 5th digit decodes to 4-5k lbs.

Cab has the 'small' trans tunnel, which would be for an auto.

The bed is from another truck, as well as the chassis, Dana 44 and Dana 60, 8 lug wheels, 318 4bbl, granny gear manual trans.

So what's the difference between a W250 and W350?
 
Just off the top of my head… 205 gear drive transfer case, 1350 U joints, HD 70 rear/60 front axles with welded on ductile steel spring pads and thicker tubes, and steering link setup. And it seems like the spring hangers and shackles are also different, too. 3/4 ton has quite a bit of parts that carry over from the half ton…
 
Garrett Ellison said:
727 setup for a married transfer case/transmission should be the correct setup.
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I take it could be from a bb or sb?

Also thinking I could just use the existing brake pedal, and an aftermarket floor shifter.

Still open to a rebuilt or new manual.
I've searched the truck forums, most threads are auto to newer manual, full of conflicting info or just end with no resolution.
 
Yes, 1974 or 1975 and up small or big block. I don’t remember exactly which year went from divorced drive to married with the rear double flange housing extension.
 
matthon said:
Do you have any of the auto parts for sale?
Your NP435?
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I have a brand new Perfection clutch kit for that transmission if you need one. $100.Shipping would be expensive though, it's heavy. Unless you want to come get in S.E. Pa.

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matthon said:
Do you have any of the auto parts for sale?
Your NP435?
Click to expand...
The NP435 got scrapped because it was like digging through a bucket of rocks with the shifter and would pop out of every gear. I sold the 727 with the 318 when I finished the 440. I think I have the brake pedal somewhere if you want that you can have it. I also have an auto steering column from I think a ‘90, but it’s kinda junk.
When I first got the truck it had a blown up 4x4 727 in it mated to an NP208 transfer case. When I got NP435, it came with a good NP241 transfer case so that’s what I run now, they’re interchangeable. I found a decent 4x2 727 and rebuilt it using the tail shaft and tail housing from the blown up 4x4 727.
I forget when they changed it but the tail shaft splines (internal side, not transfer case side) are different in some years. I think if you stick to the 80s they’re all the same.
Also, the 4x2 and 4x4 steering columns have different steering wheel splines for some reason.
 
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Find a late 80’s /early 90’s auto trans with OD from a 4 wheel drive.

But, is your t-case married or divorced?
 
A 518/46RH will work, but you’ll have to add a lockup and overdrive off switch. It’s best to get it from a donor truck so you can grab the drivelines, too. You would probably be getting into the spline count complication, so you’d need to grab the matching 205 transfer case, but an NP 445/435A or 435D according to Novak The Novak Guide to the New Process 435 Transmission
(known as the close ratio, the 435 is known as the geometric transmission) is a lot fun as they have about one third of the shifter travel as a geometric geared transmission and can be shifted quickly. But, they’re almost always in full ton application and getting hard to find. You’d have to change or modify drivelines or use 1310 to 1350 U joints. And if you’re in the 33 inch or taller tire range, the whole deal works a whole lot better with 4.56 and lower gears. The dually trucks I’ve seen outfitted with these transmissions came with 4.56 or 4.88 gears, but 5.13 or even lower would not surprise me for heavy duty utility service. The best option may be a Dodge NV4500 5 speed (I’ve even seen a very few of them in a half tons!), but they’re usually pretty pricey. Speaking of pricey, something for your viewing entertainment. But it talks about the different spline arrangements and strengths of different units.
NP203/NP205 Doubler Kit
I’d love to outfit a truck with one of these setups. Being able to use front axle drive would have been handy off road more than once when the rear started trying to slide out off camber embankments…
 
matthon said:
1984
The cab/front clip has the VIN on the dash, door jamb, under bottom of hood, and it's from a rust free 2WD automatic 1/2 ton, according to the VIN, and iirc the 5th digit decodes to 4-5k lbs.

Cab has the 'small' trans tunnel, which would be for an auto.

The bed is from another truck, as well as the chassis, Dana 44 and Dana 60, 8 lug wheels, 318 4bbl, granny gear manual trans.

So what's the difference between a W250 and W350?
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If it has the small tunnel it's not an original 4wd cab. Every 4wd I have had from those years had the big tunnel no matter what transmission was in there.
 
Yes, married setup. The 518/46 RH had an overdrive off button up on the command control center on the dash that was similar to the Cargo Light button.
 
matthon said:
Don't know yet.


I would have to asap. And/or junk it asap.
No room for another vehicle.

I think $1,200 is way too much, and also just right.
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That is a parts gold mine for you, it would have everything you need.
At least scrap price is up now, that truck is worth around $400 after you take what you need off it.
 
I would possibly be interested in the doors for my ‘90 to put it back to factory color with, even though shipping would be tough with them.
 
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