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I was asking about tranfer case swaps into my early bronco on classic broncos. com and some one posted all these horror stories about it. Let me know what you think. here is the link:

http://www.classicbroncos.com/forums/showthread.php?t=110468

here is the text of the most worrying post:

I was able ride in and drive J. Miley's 4BT Bronco conversion and we brain stormed a lot on the problems that all the torque from his 4BT created. First, I believe an NV4500 would probably require less adaptation for a 4BT than a ZF, but in answer to your question - an NP205 would bolt right up to a ZF (with minor grinding for the shift rails) and would probably have the strength to hold up to the torque. By the time you adapted and built a D20 to handle the torque you might as well buy an Atlas II.

J Miley used an NV4500 and an AtlasII in his. It had so much torque it pretzeled his drive shaft on the first drive. When he tried to see what low range and 1st gear was like, it ripped the brake pads off trying to hold it at idle in the driveway. After building a monster traction bar to limit the rear axle wrap, it would still twist the frame and compress the front end and every time he shifted it would put you in the next lane. His EB was one of the best engineered Broncos I've ever seen, but with the 4BT it wasn't safe on the street and was prone to breaking the weakest link (U-joints, axles, driveshafts, etc) offroad.

He concluded that to make it safe and reliable on the streetand trail a 4BT EB would require D60's front and rear with a 4 link suspension. He also said if he was doing it again he'd use a TH400 like they came with in the delivery vans to absorb some of the brutal torqueand make it more user friendly.

He spent an awful lot of time and money getting the boost, fuel delivery and intercooler just right. There's a lot more to it than you would think. In reality he said he'd never do it again and would have gone with a FI 351W/NV4500 and Atlas II.

On the cool side, it would absolutely pin you to the seat in any gear and it was loud as hell. I'm not trying to discourage you on your project, just share what he learned. He did it for the adventure of the project and was able to sell it for a nice price. The guy who owns it now lives in CO, but does not participate on this board.
 

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I haven't followed the link, but from reading your post, someone is on drugs. The 4bt does have great torque for an engine of its size (4 cyl., 3.9 liters) but a good running big block puts out as much torque, and doesn't do all of those scary things. Look at all the people who put them into light weight Jeeps, including Wranglers and Comanches, which weigh less than an EB. The part about ripping apart brake pads is especially funny. The force of stopping a vehicle from 60 mph is many, many times greater than holding back ANY engine at idle. Its just a complete crock. Ignore idiots like that and learn from the people here who have done it. I hope to test drive my swap next weekend, putting me one notch higher (Step 1: Dreaming of a conversion, step 2: Owning a 4bt to use for a conversion, step 3: actually DRIVING my own conversion!) and I am constantly browsing this site to learn more from those with lots more experience.

By the way, for comparison, some of the 6b guys with seriously bombed engines are making 1800+ lbs. of torque. Even a mildly turned up 4bt is just a toy compared to those, and most of those guys are still running stock driveshafts and axles. You'd be surprised how much a vehicle's drivetrain can take.

Jim
 

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That is just bizarre if you ask me. I used medium to even light duty parts for the most part on mine and I had no issues at all. It started/stopped/tracked great. I used a super thin rear axle out of a late 80's toyota pickup ion mine with a 8" ring gear, a regular duty NP241 out of a 305 powered Dodge pickup, a regular duty V8/small V8 NV4500, and had no issues at all... I think the overpowered nature of his truck was maybe related to it being overpowered somehow or the power turned up or honestly just shifting and a using it tougher than need be. The only thing that ever broke for me was a couple birfields, pretty common with SFA Toyotas...
 

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I built a 1973 EB for my dad using a Cummins 4BT, NV4500, NP241C and stock axles. I have had absolutely no problems. Yes, there is a ton of power, but I am not breaking parts.

I think the post on the bronco site is complete BS!
 

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If the only way to tame the 4bt is to run an atlas, then we're in big trouble. Money wise. I guess I will have to find out if my d20 and disk brakes will handle the massive power. That's just hard to believe.

Eugene
 

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I believe this story should be taken with one of these:



'cause a grain ain't gonna cover it..
 

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Manual transmissions and high torque always tear up stuff faster than an auto - there's no slippage, especially crawling, but I digress. Whoever wrote the article is smoking crack.

 

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Old Miley.........

Don't believe half of what you read.... he had several aliases... he would start a thread and answer his own posts under a different name.. I can't believe he is a public school teacher in Colorado!

In fact SWA0330 thought I (High Pressure) was Miley... It's so funny...because when it all started breaking loose that he had several aliases... I actually thought SWA0330 was Miley....

I do believe there was some truth to his posts.... an early bronco, Cummins 4BT.... not sure about the rest...

Just an example ... he claimed he was running a 6cm2 turbine housing... he never confirmed the turbine housing casting part number..

I believe only HX25/27 HE221 models from Holset offer that size of critical area turbine housings. At least I have never seen one for an H1C...
 

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J Miley used an NV4500 and an AtlasII in his. It had so much torque it pretzeled his drive shaft on the first drive. When he tried to see what low range and 1st gear was like, it ripped the brake pads off trying to hold it at idle in the driveway.
I think this fellow need to be nominated as a candidate to this years DARWIN AWARDS in the 4WD class! :eek:
 

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That's one Crazy link of wasted time ,I drove a EB with a Cummins ,they do just fine.

Preston ,

It will be fine , don't worry about .We Can talk more if you want.

Scott
 

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If the brakes were being ripped off...... why not PUSH IN THE CLUCH?!
 

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I saw miley's rig on his page he used to have. Looked like he did it right.

As for the 4bt swap being dangerous I'd say that's "sky-high rhetoric".

It's about as dangerous as the engine you got in there right now.
 

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My eyes have finally been opened to the serious danger of 4BT use.

Are people really that stupid? I've seen 800+ horse 460's stuffed in EB's running paddles at the dunes with a big bearing 9 in the rear and leaf springs.
 

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"I've seen 800+ horse 460's stuffed in EB's running paddles at the dunes with a big bearing 9 in the rear and leaf springs."

And I've seen 4bt's deliver... ...Frito chips
 

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I built a 1973 EB for my dad using a Cummins 4BT, NV4500, NP241C and stock axles. I have had absolutely no problems. Yes, there is a ton of power, but I am not breaking parts.

I think the post on the bronco site is complete BS!

I have the same exact drivetrain and agree with it being BS.
 

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You can see my comments in the thread on classic broncos. Some sites do a good job of repeating bad info and the good ones weed it out. I'm not sure if that site has been perpetuting it or if it just weeded the bad info out. :) That is what I like about most boards these days, seem to have enough people and recent enough info that they have pretty good tech... :)
 

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Ive been a member of cb.com since late in 2001. Miley has/had a reputation for being on the strange side. If you're having reservations talk to Scott (swa0330). I think he's on here as well. He claims his is perfectly streetable. From what I read in his posts, I think his opinion is trustworthy. There are a few other guys on cb.com running 4bts, none of which claim to have miley's problems.

FWIW, Ive recently gotten back to work on my bronco, have a 4bt-zf-np205 in the works. Cash is short, so it won't be together for a while.
 
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