Transfer case is gear drive or (ugh)chain drive?
 

:-huh I guess its a little late to find out for sure, but does the 2004 F-250 4x4 I just bought have a chain drive or gear drive transfer case? I have been told both... :-X02 obviously someone is wrong.

Chain drive. :)

If the (ugh) in your post is referring to the weakness of chain drive transfer cases, take a look at this.
http://www.newventuregear.com/tcases.html

You've either got the NV231 (manual shift) or the NV273 (electronic shift). I think with a max torque rating of 7980ft.lbs., you'll be ok no matter what you throw at it!

I bought this truck because I had a 95 dodge dakota and had to have the transfer case rebuilt at 80,000 miles. (And I never used the truck hard). It was very expensive. So please continue my education or tell me something I want to hear like how much better this transfer case is than the little dakota's. So does this one company supply the transfer cases for the big 3? For the record I have a F-250 supercab, 8' bed, V-10, and 3.77 limited slip rear end and 6 speed manual transmission, and manual get-out and lock 'em in hubs.

Thank-you both for replying.... And take pity on the uneducated.

:-tap

Why is the electronic shift rated so much higher than the manual? Is it really that much tougher?

He meant the manual shift is the NV271, not 231. The NV271 is rated the same as the electric shift NV273 which is 7890 ft/lbs.

Yes, that transfer case is substantially stonger than your dakota case

You should use your 4wd on a regular basis to keep everything operating correctly. :-X10 :)

Chain
 

Yes my 2003 is chain and I trashed it at 20,000 miles. Thank god it was under warranty and Ford replaced it. It is a sound you will never forget if it goes.

Transfer case discussion
 

First Thank you to all who replied. Good information.

Going off on a tangent. the same guy who (verbally)told me I had chain drive and caused me to come to FTE for confirmation has subsequently told me new venture makes a gear driven transfer case model 205 that rock climbers use. He thought it might be possible to install it. I assured him that would only become a possibility if mine went out and was not under warranty. Anyone care to comment on this ?

Still waiting for someone to tell me how many manufacturers use new venture transfer cases.

Can someone explain to me why the NV271 is rated (7890 ft/lbs. torque) for 18.5 times the torque my V10 (425 ft/lbs torque) puts out? Am I missing something here? Wouldn't that (7890 ft/lbs. torque) be equivalent to several thousand horsepower?

:-wink

When you take 425 ft/lbs and multiply it by the first gear ratio (????) maybe and then the t case ratio (????) and then a safety factor.....

I have a New Process 205 transfer case - in my '74 F250 !!!! It's old, it has over 300K miles on it, and leaks like a sieve. Never broke. But I doubt it could be retro-fitted into a brand-new SuperDuty :)

I looked around on the web, and the Dodge 2500 and up use the same transfer cases. These things are very strong. The chain should last just as well as a gear-driven, maybe even better, because the idler gear in the middle of a non-chain case takes a lot of strain and can fail just as easily. The key is lubrication.

The reason the torque rating is so high is that you have to take into consideration the transmission gear ratios. With a 6-speed, low is 5.79:1, so take peak torque from the V10 (425) and multiply it out, that's 2460.75 ft-lbs out the back of the tranny. Then, if you use 4x4 LOW, that's another 2.7:1 gear reduction, that's 6644 ft-lbs. If you have a diesel, putting out over 500 ft-lbs, you get pretty close to the max rating.

Check this out:

http://www.landscapemanagement.net/l...l.jsp?id=93085

GM uses the NV273 (electric shift) in their medium-sized trucks.

Um... if they use the same transfer case as our SuperDuties in a medium-duty truck, what do they use in their pickups? :)

GM is really proud of the NV273 in their medium duty trucks. I compared the weight of comparably equipped F-250, chevy 2500 and dodge 2500 and the Ford was roughly 1000# heavier. I suspect this is only one of many reasons why it is heavier.

Thanks for the link.(and response)

Krewat

Thanks for a super explanation and also your thoughts on the possibility of a retrofit. I think I will find something else to worry about.