Anybody done a 400t-4500 swap on a 4x4?

[esbstuff]

Thinking about doing a 400t to nv4500 swap on my 87 V30. I understand the usual auto to manual stuff, but what t-case is best? I have a 205 now... and I would like use the best available t-case. I would like to stick to all gm parts, as I probably have it... Really looking for someone that has one in place now.

[hatzie]

Are you looking for ease of installation or the toughest transfer case?
IMHO If you aren't competition rock crawling I'd get a good NP208 or a RHD NP241 put in a new chain/sprocket set, if you got a hi-mileage unit, and sell the 205.

The NP208 & NP241 Right Hand Drop with 32 spline input are a bolt in.
The stock NP208 & NP241 have very low range gears... The NP208 is 2.6:1 & the NP241 is 2.72:1.
The correct 32 spline NP241 is somewhat rare as it was only used in the RV trucks with the TH400.
The 208 & 241 are aluminum alloy chain drive cases that some say are not as tough as the gear drive NP205. However they are a bolt on to the NV4500, they're geared better, and they're very light.

You already own the correct NP205 for the swap. Your NP205 is gear drive instead of chain. This makes it tougher than the 208 or 241. The cast iron case filled with gears makes it VERY HEAVY. The 1.96:1 low range gears are not as aggressive as the 208 or 241.The NP205 will need an adapter kit $$$ from Advance or Novak. The adapter kits require a shortened mainshaft on the NV4500.

The .7:1 or .8:1 ratio difference may not seem like much. I've plowed with an 79 K20 with a TH400/NP205 and a 93 K2500 with an 4L80/NP241. They both had 4.10 gears and the same tires for the last/first year I owned them ( I moved the winter tires and wheels from the rotted out K20 to the "New" K2500 ). There was a major difference in low range. The 93 was VERY slow in low range and could push back snow banks that I needed a Bobcat to move before.
It wasn't really a fair comparison... the 79 had a strong 454 and the 93 had a 350.
I used that 93 up. Doing landscaping and plowing for 200,000 miles isn't nice easy service. I had ZERO problems with the transfer case. Case oil was changed every 50K... along with that &!*@ 4L80E... I went through five 4L80 transmissions (if you count the one I put in just after purchase), one 14 bolt full float rear and the transfer case was just beginning to make noticeable sloppy chain noises at 246,000 total miles.
I was done with school and landscaping at the same time as the truck.

[arrover]

Good post hatzie. What are the differences between the NP208 and the NP241? Is one more desirable than the other?

[esbstuff]

I should say no rock crawling for me. I more interested in the OD than anything. Single digits MPG sucks at X.XX per gallon. Its in a wrecker that I use every day. I just know that the 400 will puke it guts one day and I don't mind to manual shift. For the price of the adaptor, I would prefer to use the 208. I have a 4500 4x4 trans in stock and have a good 208 also.

Something else I was thinking about would be using a 4L80 with a 208, but then again I would have to splurge on a stand alone computer.

Any idea what the lenght differance is on these 3 combos? Just wondering how the 4wd drive shifter holes will work...

[esbstuff]

Ok, got a 91 4x2 square found that has a 4l80 (core). My search has turned up that I will have to shorten the rear shaft and lenghten the front one, but what about the wiring? The 87 has already been updated to a complete a 89 harness... so can I just change the engine harness and computer and run? Or will I need to change the dash harness as well? I guess I should say that the 89 is an a/c truck and the 91 a non a/c truck and I want to keep the a/c! And how about the adapter from the trans to transfer? I will run the 205 or the 208, it makes no differance to me.

[Cheng]

I am currently planning a swap from a SM465 trans to the NV4500 trans to get overdrive.

My 85 K30 has a NP205 transfer case installed and I feel that a gear driven cast iron case is stronger than the early aluminum chain driven cases. (not trying to compare to today's NV271 etc....)

From my research there are two types of NP205s.

Early style mounted to the transmission with eight bolts.

Late Style mounted with the standardized round six bolt pattern found on the NP208.

My truck has the late style NP205.

I believe that my NP205 will bolt up to a NV4500 without a problem.

Worst case for me will be swapping to the correct length input shaft. (Short 32 spline)

I found a lot of my information at these two links:

http://www.high-impact.net/transmiss...case_NP205.htm

http://offroaddesign.com/catalog/NP205tech.htm

[hatzie]

Originally Posted by arrover

Good post hatzie. What are the differences between the NP208 and the NP241? Is one more desirable than the other?

They're both chain drive with planetary gear reduction. The 241 has a slightly lower low range but it has a thinner case and right hand drop was only used on the RV squares.

[ozark]

my 88 k30 had the oringinal 205 in its nv4500 conversion.

[hatzie]

Originally Posted by ozark

my 88 k30 had the oringinal 205 in its nv4500 conversion.

I've never seen one of the round bolt pattern 205's in person. I've read that they were out there just rare.
Did it bolt up directly to the 4500 or was a custom adapter needed?

[Wrecked1982]

i love your push bumper! i want one exactly like that on my 85 k35 wrecker. is it still available?

[ozark]

Originally Posted by hatzie

I've never seen one of the round bolt pattern 205's in person. I've read that they were out there just rare.
Did it bolt up directly to the 4500 or was a custom adapter needed?

There was about a 3/4 or 1 inch adaptor or spacer between the trans and transfercase. The previous owner said it was advance adaptors part.

[ryanroo]

Originally Posted by ozark

There was about a 3/4 or 1 inch adaptor or spacer between the trans and transfercase. The previous owner said it was advance adaptors part.

this is correct if you dont swap the input, the newer round pattern 205s have an input that is about 1.625" longer that the older figure 8 32 spline 205s. the inputs are a direct swap for one another and if you go that route no adapter is needed. when i did my swap in the jeep i used the AA adapter plate because it was cheaper than buying a new input. not to mention without it the driveline was that much shorter to the front and i wanted to avoid that.

the round pattern 205s started in mid 85 and continued until they quite production of the squares v30s.

here are a few pics

this was out of an 86 k30 i also swapped in a 32sp front output from a dodge



guts everywhere



this is the AA spacer ring







i cant remember from the build if the 1350 CV would have gotten into the tailhousing on the tranny if i had not used the spacer as well. it may have been an issue.

[yousesteers]

This may be totally irrrelivant to running the gas engine. I am running a NV4500/205 combo in my Cummins swap K30. I had to pull the seal out of the back of the NV4500 and put gaskets on the adapter as the conecting sleeve was to long and it hiit the sleeve. You can find factory adapters that change the race track pattern 205 to a round pattern that the NV4500 uses they were used on some Chevys and Dodges. The input shafts can be swapped in the 205 to get the right spline count for the transmission.