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4L80E to np205???

Nosferatu49534

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Thread starter #1
Will an np205 bolt to, and work with the 4l80E? There's one for sale very close to me. Worth the buy or will the electronics get ornery?
I should also add my truck is a 97' reg cab.
I know I would have to add floor shifter and change the front diff to a manual engage as well.
 
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#2
I would think you should be able to keep the electric actuator for the front end. Might have to disconnect the wiring from the transfer case if it is the push button model.
 

THEFERMANATOR

FRANKENBURBAN
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You do know the 205 is a passenger drop, right? All gmt-400's are drivers side drop with ifs, all GM 205's were passenger side drop for asolid front axle. Ford had a drivers side drop version, but it used a different bolt pattern. And only the 91 GM 205 came with an output speed sensor which your 97 MUST have. It costs a fair amount for the aftermarket pieces to add a vss to an np-205. Don't forget the weight difference. A 205 weighs roughly 200 lbs iirc vs the 70 lbs your aluminum case weighs.

You COULD make a 205 work, but why? I know many are obsessed with them and convinced the cast iron case with all gear transfer case is stronger, but this MYTH has been proven false time and time again. Many have broken the 205 and proven it isn't bullet proof. I don't see any reason to get rid of your current transfer case unless you're one of the ones scared of the push button setup(which have proven to be pretty reliable really), in which case why not swap over to a np-241 floor shift which came stock, and could easily be swapped in if you get the right model/input shaft. And be extra carefull on the 205's, not that many models came with the 32 spline input from my understanding, I believe the 19 spline was more common.
 

Nosferatu49534

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Thread starter #11
You do know the 205 is a passenger drop, right? All gmt-400's are drivers side drop with ifs, all GM 205's were passenger side drop for asolid front axle. Ford had a drivers side drop version, but it used a different bolt pattern. And only the 91 GM 205 came with an output speed sensor which your 97 MUST have. It costs a fair amount for the aftermarket pieces to add a vss to an np-205. Don't forget the weight difference. A 205 weighs roughly 200 lbs iirc vs the 70 lbs your aluminum case weighs.

You COULD make a 205 work, but why? I know many are obsessed with them and convinced the cast iron case with all gear transfer case is stronger, but this MYTH has been proven false time and time again. Many have broken the 205 and proven it isn't bullet proof. I don't see any reason to get rid of your current transfer case unless you're one of the ones scared of the push button setup(which have proven to be pretty reliable really), in which case why not swap over to a np-241 floor shift which came stock, and could easily be swapped in if you get the right model/input shaft. And be extra carefull on the 205's, not that many models came with the 32 spline input from my understanding, I believe the 19 spline was more common.
I was not aware of the difference in drop sides. Thanks for the heads up. :) That's why I asked. Definitely not worth the headache then. I just knew they were gear drive and supposed to be stronger. But apparently not. :)
 

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FRANKENBURBAN
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I was not aware of the difference in drop sides. Thanks for the heads up. :) That's why I asked. Definitely not worth the headache then. I just knew they were gear drive and supposed to be stronger. But apparently not. :)
It's a myth about the extra strength. Many have proven this, but it still remains that everybody is dead set that cast iron is stronger than anything aluminum. It's no different than all those who say a diesel won't last under heavy duty use, yet the duramax has proven that one false, yet it still gets told as gospel(I even had a guy who owned a new 6.7l powerstroke tell me aluminum heads won't last on a diesel, imagine his face when I pointed out his powerstroke has aluminum heads on it). The np-24x series transfer cases are not the strongest out there, but they are quite tough as you rarely hear of one failing unless it's been used and abused in which case any transfer case will fail.
 

Will L.

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#13
The 2 points of gear drive vs chain drive and aluminum case.
Chains stretch. The chain kits which are usually good to 100,000, but in certain situations you can stretch at 75,000 real high hp and torque and some people have needed to replace at just over 60,000- but at crqzy power an atlas should be in there.

Aluminum breaks from rock impact offroading. Youbcan damage both really, just aluminum is easier. Put on a piece of 16 gauge smooth plate under it from one side of frame to other and problem solved far better.
 

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FRANKENBURBAN
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Also of note, with a 205 you MUST redo your trans mount. The 205 is to heavy to hang off of a trans, so must support the transfer case or else you'll snap the trans case from the weight. The chains will stretch, but they don't normally just snap from shock loads whereas a cast iron case transfer case can crack/split from impact/shock loads.
 

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FRANKENBURBAN
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I have always been a fan of the 241. Works nice since thats whats in most hummers, but fulltime 4wd version.
I thought the hummers used a np-242 for a full time case with a center locking differential.

Just looked and the h1 uses a 242. It's similiar to the one Jeep used, except the h1 version has no 2x4 position. Predator uses Jeep parts to convert the H1 version to have a 2 wheel drive position, and sells them for a small fortune.
 
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Will L.

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#17
Yup- yet you are correct as always! I mixed up 241 and 242.
And I bought the same jeep parts and converted mine to 2/4 instead of full time 4wd. Biggest mistake I made with my hummer yet. Does not help mpg. Any wear savings of front axle is lost to rear wearing quicker. And because of the near perfect balance of 50/50 front axle to rear, it changes the handling in a bad way. Freeway onramps I used to take at 55mph now only 35-40mph. And this was with no other changes at same time.

As far as Predator :makes so great parts and has made some customers happy with thier work. Others had horrible work done and everything I seen them sell is WAY overpriced. Like the relabeled lift pump that is $30 Rockauto go for $100. Or triple price on restomod A/C kit.
 

Nosferatu49534

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Also of note, with a 205 you MUST redo your trans mount. The 205 is to heavy to hang off of a trans, so must support the transfer case or else you'll snap the trans case from the weight. The chains will stretch, but they don't normally just snap from shock loads whereas a cast iron case transfer case can crack/split from impact/shock loads.
Your wealth of knowledge is great. :)
 

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FRANKENBURBAN
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Yup- yet you are correct as always! I mixed up 241 and 242.
And I bought the same jeep parts and converted mine to 2/4 instead of full time 4wd. Biggest mistake I made with my hummer yet. Does not help mpg. Any wear savings of front axle is lost to rear wearing quicker. And because of the near perfect balance of 50/50 front axle to rear, it changes the handling in a bad way. Freeway onramps I used to take at 55mph now only 35-40mph. And this was with no other changes at same time.

As far as Predator :makes so great parts and has made some customers happy with thier work. Others had horrible work done and everything I seen them sell is WAY overpriced. Like the relabeled lift pump that is $30 Rockauto go for $100. Or triple price on restomod A/C kit.
I could see the wear issue since the big hummers only use a amc 20 diff(converted over to ifs). They're only marginally stronger than a dana 44. When I found out that was the diff used in them, I didn't know how the heck they held up to the duramax.
 

Will L.

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#20
More than one has went to the recycle can. Stock 6.5TD can be handled, but I’ve played with a few hopped up 6.5s that can take them out. Usually the breakage occurs when wheeling hard so people blame it on how hard the obstacle is or an error the driver makes. In reality it should be beefier. It happens more often to the guys running lockers, the torson diffs last longer under abuse. More than one person has found their way to a Ford 9”.
 
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