1480 u joint to NP205 transfer case

stillsmokin

stillsmokin

all out of fuel
Joined
Jan 23, 2007
Messages
228
Went to the local driveline shop to have a custom driveshaft made for the first gen Dodge and ran into a stumbling block.

I have 1410 joints now, but wanted to put a larger stub shaft on a 4 or 4.5 tube with a 0.125" wall thickness. Problem is, to go bigger on the stub I need to step up to 1480's. I don't think I'll actually gain much by stepping up to 1480's, the bearing caps are a little larger I guess. The only way I can figure to do this is to run a custom NP205 32 spline drive flange and attach a 1480 flange yoke to it. I'm a little concerned about torque shear on the bolts of that mess. I'm open to suggestions.

The Chevy/GMC brush pullers on the forum might be able to help me out...

Someone surely makes a simpler solution?
 
I think the 1410 is adequate for the strength of the 205.
 
Why do you wan the tubes so big? The output shafts will fell before you break or twist a tube....
 
There is a new rear output available, if you know where to look. 42 spline, the dimension slips my mind. I want the big tube for future endeavors. There are gas fueled trucks in the 1000 HP range running spicer non greasable 1410's with no major issues. Just want to be as strong as possible for now since I have to build a shaft anyway.

The factory size splined stub on the prop is the weak point right now.
 
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The 1000hp gassers are running 5:13 gears?
Also they are probably less then 1000 lb/ft of torque also right?

Only thing I am saying is don't put too much money into the NP setup, if you could possibly go to a proven setup that works in the diesel world.
 
zstroken said:
The 1000hp gassers are running 5:13 gears?
Also they are probably less then 1000 lb/ft of torque also right?

Only thing I am saying is don't put too much money into the NP setup, if you could possibly go to a proven setup that works in the diesel world.
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You are right! The gassers are probly running 6:20's witch takes a LOT of the strain off the transfer! Back a few years ago i split the case of a 205 (more than once) with 800HP gasser running 5:13's.... 205's are not as strong are the people think!!! 241 hd's and 271's are the way to go...IMO!
 
Pro-Fab rear output shaft for the 205 is larger and then you can get a 1480 yoke for it. If you don't mind being in low range all the time then get the complete gear kit from Pro-Fab.
 
I have about 1100 on tap with 3.73's front and rear. Pro fab guts in the 205 and on occasion breaks the input gear of the pro fab setup.
 
tthomp said:
I have about 1100 on tap with 3.73's front and rear. Pro fab guts in the 205 and on occasion breaks the input gear of the pro fab setup.
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What rpm is the 1100 hp? Gas or Diesel?
 
One thing to remember is the gas and diesel pullers are quite different. The gassers weigh 6200 right? I have hooked with the outlaws, which are 485 cu in engines, some of them turning nearly 10,000 rpm. They are running profab and rockwell rearends. My truck ran right with them. That should give you a comparison of the stress a diesel puts on a driveline. An 800hp diesel will pretty much blow apart a stock D80 or AAM 11.5.
 
your right it is about 8300rpm max HP. I hook 6500# and 8000# pro street gas/diesel. I understand the stress's well. :)
 
Well thanks for all the np205 bashing guys.

FWIW, None of the tranfercases utilized in pickup trucks were ever designed to hold 1000 TQ/HP, they all break eventually. I've worked with the 241HD and 271 and saw plenty of them broken in stock trucks and at the pulls. When the chain snaps there isn't much left to rebuild in those units. Then there are all the problems from plugged pump screens and steel vs. aluminum corrosion. I saw a duramax recently where the internal pump was cutting its way out of the case from the inside! I'll keep the old iron and live with it.

The 205 just needs a 3:1 straight cut gear set and a few bearing changes. Somebody probably has one out there already. It will most likely hold all I want to make powerwise as I only have time to hook about 4 times a year, if I'm lucky, and I won't be running the 2.8 or 3.0 classes either. There is no big prize money to snatch up here and not much for sponsors to offset costs so 500HP diesel will keep a guy competitive in a 2.6 (if we can get that class to have a following).


I just wanted to see if anyone had an alternative solution for my coupling problem.



zstroken 485ci gas is street cubes, not much of a comparison. How about an 10 liter arias hemi, donovan, or keith black with a 14/71 high helix you can hang with that right:hehe: Turbo diesel vs. blown, alcohol injected, mountain motor sounds fair to me.
 
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stillsmokin said:
Well thanks for all the np205 bashing guys.

FWIW, None of the tranfercases utilized in pickup trucks were ever designed to hold 1000 TQ/HP, they all break eventually. I've worked with the 241HD and 271 and saw plenty of them broken in stock trucks and at the pulls. When the chain snaps there isn't much left to rebuild in those units. Then there are all the problems from plugged pump screens and steel vs. aluminum corrosion. I saw a duramax recently where the internal pump was cutting its way out of the case from the inside! I'll keep the old iron and live with it.

The 205 just needs a 3:1 straight cut gear set and a few bearing changes. Somebody probably has one out there already. It will most likely hold all I want to make powerwise as I only have time to hook about 4 times a year, if I'm lucky, and I won't be running the 2.8 or 3.0 classes either. There is no big prize money to snatch up here and not much for sponsors to offset costs so 500HP diesel will keep a guy competitive in a 2.6 (if we can get that class to have a following).


I just wanted to see if anyone had an alternative solution for my coupling problem.



zstroken 485ci gas is street cubes, not much of a comparison. How about an 10 liter arias hemi, donovan, or keith black with a 14/71 high helix you can hang with that right:hehe: Turbo diesel vs. blown, alcohol injected, mountain motor sounds fair to me.
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T
Street cubes? LOL, I thought I was in a street class!
I guess if you want it fair, let me double the displacement of my engine, if they are doubling theirs. I was using it for illustration purposes, that a 1200 hp 6200 lb gasser puts similar stresses on things as a 600-700Hp 8000 lb diesel. Remember the gasser guys are probably running a heck of a lot more gear than the diesels though.
 
They do have a lo-max 3:1 kit for the 205 but if I remember correctly it requires a different housing. I think that the 205 will hold up just fine for you.
 
The 205 might hold up for a while, but I have had too many bad experiences with them. And the pro fab out puts do break in the diesels too. We broke one on my brother's truck and after all the money spent on that 205 we could have got 2 241HD's. You say you see many broken 241's and 271's, how many miles did these have on them, and how were they really taken care of? I highly doubt there have been more broken 241ld and hd's, 271's or 273's, compared to the 205's in the diesel side. But in your case, you don't have many options unless you want to swap your front axle. In your case I would do what you need to do and then regear your axles as low as you can go to help the 205 live.
 
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If you are gonna make big power the pro fab 205 kit is a must. there is a guy that makes a even bigger shaft for them if you can find him and get him to make one.

As far as gas motors go we are running a 485 with little over 1000 hp run cepeks with 23 to 25 finial depending on track. If we ran street tires we would run taller. You can't compare diesel to gas. no one will ever be happy one has turbo and one has more cubic inches one weighs more bla bla bla no one will ever be happy. Give a little to one and the other one will cry.
 
I looked into that 205 stuff a while ago.

Seems the 205 kit from Profab fixes the out put problems, doesnt fix the case.

The 205 having 3 gears is a big issue under stress. The drive gear tries to move shove the idler gear through the case. Even being cast iron it will split.

Get a damn 271 and be done with it. Seems if they can hold a 2000ft/lb diesel with 4.56's the chain aint so week.
 
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