NP205 Input Shaft Swap

[72longbed]

How much trouble is it to swap a 10 spline out for a 27 spline input shaft on an NP205?? Do you need to be a transmission specialist to do this or can someone who has built a few engines tackle it? Are there specialized tools needed to do the job? Are there a lot of really involved processes to get to the input shaft? Just want to know what I might be getting into before I attempt it.

Thanks for the help,
72longbed

[micscottj]

i did that swap several years back and i am certainly not a transmission guy. the only trick was that there are some needle bearing you have to be careful with. if you put some heavy axle grease on those needle bearings, they will stay in place for you though.

[MAC67]

Originally Posted by micscottj

i did that swap several years back and i am certainly not a transmission guy. the only trick was that there are some needle bearing you have to be careful with. if you put some heavy axle grease on those needle bearings, they will stay in place for you though.

what he said ,, ive done a few of them , pretty simple swap , be sure and use some heavy grease on those big needles bearings , they can be fun to try and fish out

[784X4GUY]

Just wondering but why would you wanna swap out the 10 spline for a 27 spline? Just for strength or what? Later Mike

[72longbed]

Mike,
I would rather just leave the 10 spline shaft in there but have been told that my 700R4 won't adapt to a 10 spline shaft NP205????? Do you know something different?? Is there a way to make the 700R4 fit the 10 spline NP205 without tearing either one apart??

Thanks,
72longbed

[784X4GUY]

Oh man I really don't know that's why I was asking, cause im really interested about it. Ive never heard of anyone doing it and was just wanting to see if it was capable of being done. Good luck with it though...Later Mike

[MAC67]

yeah advance adapters , get ready to shell out some dough , im not for sure but you will probably have to go tht route anyways , i believe the 27 spline is for the th350 , your 10 spline shaft means your 205 came from behinda 4spd manual , ill do some searchin for ya and see what i can find

[MAC67]

ok here ya go this is what you need , and its olnly 250 bucks , this will let you mount your 700r4 directly to your sm465 10 spline 205 transfer case with out changin anything
heres the link

http://eshop.advanceadapters.com/com...roduct_id=1519

[4x4Poet]

Good info, but the 10-splined is the weakest input shaft among the four or so NP205 shafts used/available. If you mic the 10-splined at the depth of the splines and compare that to the 27 or 32 splined shafts, you'll note quite a difference. The course-cuts leave the 10-splined shaft much smaller at the cuts than the uncut portions or the fine-cuts in 27/32-splined shafts. The 10-splined shafts also wear more easily since the course cuts do not have as tight a slip fit as fine-cut 27/32-splined shafts. The trans to xfer case adapter 10-splined spud shafts also wear easier for the same reason. ORD has a good NP205 tech page.

72longbed, if strength for a powerful engine, agressive driving, ar large high-traction tires is not a concern, the 10-splined is fine. After all, they hold up for years behind manuals. But serious rockcrawlers, mudders, draggers etc often need greater xfer case strength. Good time for an upgrade though, since the case is out. Check for wear on the splines. That may drive your decision, some.

JC Whitney used to sell a NP205 overhaul manual that I bought once, but I can't find it despite both a home and online search.

[MAC67]

but at the same time , i have ran many of them ,, i had the 10 spline 205 in behind a 4spd with a thumpin 402 in front of it and ran 44"boggers ,, did burnouts at cruise nights , had it in mud holes over the tires and kept thrown pedal to it and more gears , never had one break , and yes it lived a very very hard life

[meathead95]

thanks for the link mac. i thought i was going to have to buy a new transfer case.

[MAC67]

no problem ,, those guys build some of the coolest stuff , plus to add to the top post , that 700r4 is gonna puke its self wayyyyyyy before you ever damage that shaft or the 205

[meathead95]

yeah im not worried about the strength of the 205 or the shaft it is the 700r4 im worried about

[72longbed]

Thanks Mac67 and everybody else! Looking at the picture on Advance's website, it looks like that "adapter" is really a shaft of some sort for either the T/C or the 700R4?? If its for the 700R4 then it would mean a total tear down of the tranny to install it, I won't do that because it will Void my Bowtie warrantee.

Does anybody know how this part fits into the driveline? I think somebody said " thats all you need, nothing to take apart", how do you know that? Where does it go, and what will it do to the position of the engine and/or T/C on the frame?

Lots of questions, probably should call A.A. for the low down on the thing.

Thanks for the good info everybody,
72longbed

[71swb4x4]

That shaft is the output shaft for the tranny. You do have to tear the tranny apart to use it, so that may not be the way you want to go.

[72longbed]

No I won't tear apart my 700r4 Level II. I think I'll look for that aluminum 'block' type adapter that I saw on one of these threads, it's supposed to adapt a 700R4 to a TH350 ready NP205? I don't mind moving the engine forward to use it if it really works.

Anybody got any info on that block adapter?

72longbed

[71swb4x4]

When doing the 700r4 swap without the aluminum 'block' type adapter you either have to move the engine forward 1 3/4" or the transfer case back 1 3/4". Keep that in mind, when you add the aluminum adapter you will be increasing the amount that you are moving everything.
I am not sure how thick those adapter were, but they looked like at least 1", so you may still have room but I think you may have problems with the oil pan if you move the engine ahead that far. I am sure someone on here can clear this up for us.

[71swb4x4]

Now that I look at it that thing may be 2" thick. You may have to move the engine forward and the transfer case back.