Transfer case debate

[jbclassix]

Here is my dillema. I have a choice of transfer cases to use on my Suburban, I just can't make up my mind on which one to use! I have a 27 spline NP205, a Passenger drop 32 spline NP241, and a Drivers drop 32 spline NP241. I will be using a NV4500, so the cheapest would be the Np241s. I have a GM Dana 60, but I can get a HP Ford Dana 60 easily. This truck will be a daily driver, long distance driver, driven on icy roads, mountain roads, and in sub-zero temperatures, and will on occasion see hard off-roading. I have broken dodge NP231s, but never a GM 241. The 241 has a lower LOW range, and I have put over 200K miles on a GM 243 (electric version) with a solid axle with no problems. So, is the 205 adapter kit really worth it?

[Altec]

What kinda engine/power you making? Tire size, and gears?

What bolt pattern is the 205? Round pattern, or the figure-8 pattern? Besides the obvious input shaft change on the 205, I believe the transmission case needs to be modified slightly for the 205 to work. DirtyLarry is using a 4500/205 combo in his "NV4500 swap is underway" thread just below yours. You may want to pick his brain on his swap.

The low-range of the 241 seems kinda moot to me. Simply because the 4500 has a built in one. If anything I'd rather have the more mild reduction of the 205 to give you some in between options.

[DirtyLarry]

That is a dilemma. If you are running a small block in the Suburban, I would just use the passenger’s drop 241 as it will be a much quicker and cheaper conversion. My buddy puts his Dodge 241 though hell behind a 360 in a Ram Charger with ARB lockers and has never had an issue. And you are correct, the 241 has a much lower 4lo than a 205. Depending on which year of NV4500 you use, you may lose some of the low range where the 241 will help get some of that back. My NV4500 is a newer one with the 5:61 low range whereas the earlier NV4500’s had the 6:34 like the SM465’s did. I will certainly miss the 6:34 granny gear when descending steep grades.

I was tempted to use a 1989 Suburban 241 but was a bit worried about it living behind the 8.1L which is why I went the Advance Adapters route to use the 205. I used a 27 spline 205 because I got a smoken deal on it and did not want to use my old 10 spline 205 (10 splines are the worst of the 205’s IMHO). Could have gotten a 32 spline gear for my 10 spline case but that requires machining to the case. To hell with that….I went with the cheap 27 spline 205 Craigslist score.

There was a round pattern 32 spline 205 including a SM465 on Denver Craigslist a few weeks ago for around $200. That would have been a good score for either of us just to get a round pattern 205. It popped up on CL right after I got my AA kit installed (go figure). The guy must have sold it as it is missing from CL now.

I believe the 241 is a direct bolt in whereas, any 205 (round pattern 32 spline or circle 8 10/27/32 spline) will all require cutting the NV4500 tail shaft to a certain degree. It is a very unnerving feeling taking a chop saw to a NV4500 tail shaft .........but we did it anyway.

[jbclassix]

I have some time to slowly gather what I need for the transfer case... I still have to finish the body work, re-hang the spring hangers, and rebuild the tranny. The NV4500 I have is a 95 so it has the higher 5.61. I want to keep this one for the burb becasuse I eventually want to drop in a warmed over 6.5L Diesel (280-300hp) and the close ratio is nice for a diesel. I am slowly gathering parts for a built TPI 350 (300-325hp). I am pretty sure I am going to use 4.10 gears because I want to use an eaton HO72 rear axle. I will be running LT285/75-R16s so I can carry a full size spare (and price). I like being able to leave the hubs locked and shift in and out of 4hi on the fly. The Dana 20 in the Scout was real easy to shift on the fly, the 221 in my 69 GMC pick-up was too. The 241 in the 95 Yukon is, but it has the front axle disconnect to help... the 91 Burbs 241 isnt easy, but it lived its life with a plow and that might be why. The 242s in Hummers can be a bear... the 205 in the 70 burb was hit and miss easy. I will be wheeling mostly localy. I was looking into this for starter parts but can't make it down there today... look at the pics, not the description.

http://cosprings.craigslist.org/pts/2113990478.html

[Dieselwrencher]

I've done that a few times. Let me give you this little hint on the ford dana 60's in these older chevy trucks. The ford dana 60's are 5" wider than the D44's and chevy D60 fronts. I'd stick with a chevy or dodge D60 front.

[D O C]

go with the 205 and be done with it,its stronger and you can add a doubler easy enough down the road.
if you have a vss 241 you can convert the 205 to vss.
the 241 is cast alum and parts are exp.
205 cast iron all gear driven,adaptors to fit many transmissions.
i'm not saying the 241 isn't good but why settle if your building a rig,do it right the first time

[Dieselwrencher]

Originally Posted by D O C

go with the 205 and be done with it,its stronger and you can add a doubler easy enough down the road.
if you have a vss 241 you can convert the 205 to vss.
the 241 is cast alum and parts are exp.
205 cast iron all gear driven,adaptors to fit many transmissions.
i'm not saying the 241 isn't good but why settle if your building a rig,do it right the first time

Parts are expensive for a 241? That's crazy. I can get parts for a 241 cheaper than for any 205 I have broken. And I have broken more 205's than 241's. Granted the 241's I'm using are stronger than the GM ones you guys are using. The 205's just don't hold up as well behind diesels. We'll see how long the 205 lives in my Longhorn.

[special-K]

Some people don't know anything but what magazines promote for ultimate 4wd rigs. I'd use the 241 by the uses you describe,especially when you have other fish to fry ('70 GMC project). Why spread yourself too thin when you'll probably never see the benefit? From what you describe a Dana60 axle isn't necessary either. Definitely not dual cases. Hey,I'm an equipment freak like anyone else,have built,and plan to build trucks with more beef than I'll ever need/use just for cool factor. But,you asked and,based on what you say,that's my answer.

[jbclassix]

Originally Posted by Dieselwrencher

Parts are expensive for a 241? That's crazy. I can get parts for a 241 cheaper than for any 205 I have broken. And I have broken more 205's than 241's. Granted the 241's I'm using are stronger than the GM ones you guys are using. The 205's just don't hold up as well behind diesels. We'll see how long the 205 lives in my Longhorn.

You will have to tell me about breaking a 205!

[D O C]

my 241 broke and it was a 100 for used slipyoke tailshaft housing and 250 for new vss housing,i got 2 np205's for 200.
i dont buy magazines(plenty of jeeps and yotas around here.all the free info i need and want),i've spent alot of time/money building a 10 bolt to find out a week later,its still a broke 10 bolt with fancy parts.
i build 1 ton now.i dont really need it but if i want to play, i'm not scared like when i had my 10 bolts/36's.

yes a 241 can and will work fine and so would a 205,i've had 25 chevy 4x4 trucks with 203,205,208 and 241 my choice is the 205

[duallyjams]

tomato tamato
unless you are doing something extreme the np241 will work just fine and bolt right up to the nv4500.
Any one can brake anything if they try hard enough.

[maynardtruckin]

I say the 205 due to strength with the nv trans there is your low gearing. With the diesel plans and the fact that it will be a regular drives strength and dependablity will go a long way even if it never sees trail use.

[Zoomad75]

For ease and lower cost of install, go with the 241. It's strong enough for either engine choice at the 300-325 hp point. I've got a 205 in mine, but if dirtylarry has his way I'll be looking for a 241 to put behind a nv4500. In my case I'll be running a 5.3 gen 3 that's going to be a little tweaked by the tuning but no insane hp numbers. A 241 will live behind that all day long for what I put it through.