What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

np 203 vs atlas 2

K

K5dreamer

1/2 ton status
Joined
Mar 14, 2005
Posts
3,081
Reaction score
2
Location
Alexandria, Va
ive heard alot about the NP205 TC and how its the standard for the off roading crowd, gear driven, bullet proof.

i was just curious, how would yall rate it compared to the Atlas 2 TC which is as far as ive seen pretty equally rated by the trail crowd.

as far as i can tell, either would be just as good, just the atlas is an aftermarket while the 205 is a factory part.
 
I think you're confused about the NP203. People use the range box portion of a NP203 t-case for doing a "doubler" whereas the atlas is a much lower gear ratio than any factory t-case and doesn't need the use of a "range box" to get that low gearing.
 
yeah i was confused, i meant to ask about the NP205, which is the gear driven, while the 203 was a chain driven. im doing some browsing about transfer cases basically, and im toying with the idea of ditching the TH400/NP208 combo i have now, for a TH700-R4/dunno yet combo.

i was looking for something bullet proof and good for the trail.

ive found something about a Dana 300, which apparently is bullet proof, comes stock with a 2.6:1 ratio, but can be built to a 4:1 ratio, and its only weak link is a 27 spline output shaft which can be upgraded to a 32 spline shaft. and there are adapters to put it on a 700R4.

my only concern is that it seems like it was a jeep part, would it hold up behind a (admittedly weak) 6.2 diesel?
 
I can't help you on the D300 stuff because i don't know anything about those. I'm guessing they aren't as readily available as a NP205 though. The best option would be the 700R4/205 but remember that by getting rid of the 208 you're giving up gearing. The 208 has a 2.61 low range and the 205 is only 1.96 low range. This is why people go with a doubler, or even an atlas or other after market t-case. If you do decide to go with a 205 behind the 700 i would use the spacer rather than swapping the output shaft as otherwise (unless you go doubler) the front driveshaft has been reported to hit the tranny pan with certain types of front driveshafts.
 
id love not to loose the gearing from the NP208, but the guys i know all say that you want to ditch the chain drive TC's. the truck dosnt have all that much power, is the 208 a pretty solid TC for moderate off roading? the only reason i want to get rid of the 208 is i have been instilled with doubts about how strong it is with the chain drive.
 
There is nothing wrong with the 208/241 t-cases. The biggest problem is people who bash them on rocks and break the aluminum case. If you build a sturdy skid plate you'll be fine.

Don't get me wrong, an all gear t-case is far superior to a chain drive case but how many times have you actually seen a chain fail?
 
the truck actually already has a skid plate, do you mean id need to beef that up from stock? (its the military truck, dunno if civi trucks got the skid plates).

as for how many times ive seen a chain fail, i think its pretty obvious im a noob to the off roading truck scene, so never :)

thanks so much for the help by the way.
 
The stock skid plate isn't worth crap. You need to build a beefy skid plate that is attached to the frame at both the front and back and fully covers the t-case.
 
4X4HIGH said:
There is nothing wrong with the 208/241 t-cases. The biggest problem is people who bash them on rocks and break the aluminum case. If you build a sturdy skid plate you'll be fine.

Don't get me wrong, an all gear t-case is far superior to a chain drive case but how many times have you actually seen a chain fail?
Click to expand...

I have seen several 208's fail. None of the failures I have seen were related to the case being contacted. Its tough to tell what let go since the case and internals were all pretty much destroyed. IMO, 208's and 241's are only "ok" transfer cases in full size trucks.

As for your question regarding the 205 vs. Atlas, they are both very good t-cases. The 205 is marginally stronger than the Atlas, but nobody really breaks either one. The Atlas has a deeper low range (and potentially 3 speeds, depending on which one you get), the Atlas is lighter (aluminum case) and has twin stick capability (which the 205 can have, it just doesn't stock). The Atlas is at least $2K more expensive than a 205.
 
In your setup, I would be more worried about the 700 than the tcase. 700 is nice for overdrive and does have a lower first gear, but it is no way as strong as the 400. If you DD your truck and use the highway, the OD is nice. If it is more of a wheeling rig, stick with the 400.
 
The dana 300 can be run behind a chevy transmission. They put one in the bottom drawer buggy on extreme4x4 on the powerblock. There is a 4-1 low kit avalable from tereaflex. Heres a link to the install info. http://www.teraflex.biz/installsheets/low300 install.pdf

That being said, its probably easier to use a chevy case because I think you have to swap transmisson output shafts depending on which one you have.
 
the 700 dosnt really concern me, first off the truck will be primarily a DD, and only see some moderate off roading, mostly trails and national park stuff, i dont think it will ever see boulders or rock crawling. secondly i have a guy i trust to build it to my request. Ill probly run a similar setup as my IROC, full stage II B&M shift kit, extra clutch packs, corvette first to second servo, although ill run a lower rpm stall converter than the IROC has. the 208 has a 32 spline input shaft, so ill have to have him build the 700 with a 32 spine output shaft. with all that put together, and probly a tranny cooler to boot, i think the 700 will survive just fine. its also a matter of gearing, the lower first gear will nearly double my first gear drive ratio, and the overdrive will cut my cruising gearing by about a third. basically i will be able to run 4.10 gears, which combined with the first gear of the 700 will nearly tripple the crawl ratio of the truck, and my cruise will still be lower than what im running now with 3.08 gears. and thats with the stock 208 case.

id like even more though. :D im still interested in a Dana 300 if its strong enough. but if there is a way to get lower gearing out of a 205 im all ears. the atlas 2 is definatly way out of my price range, i was mostly curious about it.
 
I'm not aware of anyone that makes a 32 spline output shaft for a 700R4, i think you're going to need to change the input shaft on the 208 case to a 27 spline to match your 700R4 output.
 
absolutly :)

hmmmm..... so, 3.06 first gear, 3:1 on the lo max, and 4.10 gears...... 37.6:1 crawl ratio, nothing earth moving, but a helluva lot better than the 13:1 or so ive got now. and id still have lower highway rpms than i do now :) not a bad arrangement id say, thanks for the input everyone ;)
 
I would invest the money in gears and axles before touching the tcase or trans. You will allways destroy a 10b before anything else IMO.
 
the axles are gonna get built wayyyy down the road. the tranny swap i can do for free basically. ive got the 700R4 out of my old 89 camaro, and the TH400 out of the truck, my tranny guy will probly build me that 4x4 700R4 for free if i give him the other two cores in trade, and provide the rebuild kit.

this is all pretty much just homework, and learning, it will probly go in stages. the tranny swap will probly be first, just cuz the horrible gearing of the TH400 is killin me and my gas mileage using the truck as a DD. then ill probly do either the TC, or the axles, which i want to rebuild with detroit lockers, heavier axle shafts, and 4.10 gears, and probly a diff cover with bearing cap supports. then whichever i havent done, will get done.

im mostly just reviewing options at this point, although i can pretty much guarantee that i just keep the 10 bolt axles. If im gonna dump money into a truck with D60's and 14 bolts it will be after college and it will be a full convertable blazer powered by a duramax and allison tranny and all the problems im sure to have to deal with at that point ;)
 
You must log in or register to reply here.

Latest Posts

Top Bottom