NP205 swap is almost complete...

qwertyd10n · Post by **qwertyd10n** » June 28, 2011, 11:58 pm

Good day folks,

I just thought I'd share a little good news... my truck is mobile again! Yippee!

So, I've spent wayyy too long swapping out the original Dana 21 transfer case and 2WD version of the NP435 in my '66 F100 4x4 for an NP205 transfer case and 4WD version of the NP435. And on top of that, I replaced my two piece rear driveshaft with a big 3" one piece unit... but I got it back together on the weekend and had it out for a short drive around the block a few times tonight.

I didn't dare go to far given all the changes I made and untried components, such as:
- the 4WD NP435 is new-to-me and although it looks good, I just wasn't 100% sure
- the NP205 was supposedly rebuilt, but I realized last weekend that the reason it wasn't shifting between the ranges properly is because whoever rebuilt it installed the high range shift fork backwards and also didn't pin it to the shift rail... so what else might have they done wrong?
- installed a new 1350 pinion yoke on the 9" out back... but I went with a solid spacer instead of a crush sleeve - that was a learning experience - so I'm just not 100% sure about that either.

Anyway, everything seems great, but I didn't have it up to very high speeds staying so close to home. Tomorrow night I'll button up the transmission tunnel cover and take it out a little further abroad to see if there are any noticeable noises, vibrations, or such at higher speeds.

Here are a few pics... please don't mind the makeshift exhaust that I've hacked back together for right now, and I still have to install the side mount on the transfer case:

Let me know what you think... I'm pretty sure this is a much more robust setup and it should be able to handle the 450-500HP my new stroked 390 will hopefully be putting out!

Cheers,
Dion

slick4x4 · Post by **slick4x4** » June 29, 2011, 6:45 am

Looks like very good work

ICEMAN6166 · Post by **ICEMAN6166** » June 29, 2011, 11:56 am

looks all nice and shiny

was something wrong with the d21 or did you just want a t case with low range for off road use?

HiBoy63 · Post by **HiBoy63** » June 29, 2011, 12:07 pm

ICEMAN6166 wrote:looks all nice and shiny

was something wrong with the d21 or did you just want a t case with low range for off road use?

Yeah thats what I was wondering.

qwertyd10n · Post by **qwertyd10n** » June 29, 2011, 12:25 pm

It was a combination of factors guys...
1. the Dana 21 was in need of a rebuild and i wasn't very successful in finding parts that would be necessary to make that happen
2. my research led me to believe that the Dana 21 would not likely be up to handling power levels in the 450-500HP/500+FT LBS of torque range that my new 445 stroker FE engine is going to put out
3. I needed to beef up the driveshafts to handle the increased power as well, so instead of trying to find the desired yokes (1350) for the Dana 21, I figured sourcing those sorts of parts for the NP205 would be much easier
4. having a true low range is definitely a nice option if I ever take the truck off road or want to pull out some tree stumps somewhere

And man, did I learn a lot going through this swap... that was invaluable in itself!

Cheers,
Dion

ICEMAN6166 · Post by **ICEMAN6166** » June 29, 2011, 12:39 pm

thec strokers full torque on a bind in a mudhole in 4wd might be a bit much for the d21.

seriously though its all about the weakest link, those are always the front axle u joints.

bigger driveshafts without increasing u joint size does little in the way of preventive engineering.

i do want to see some good pics showing serious mud ruts and roostertails done with the stroker engine

CoralRed · Post by **CoralRed** » June 29, 2011, 10:19 pm

Looks very nice , Dion. Send me a PM. We should get our trucks together sometime.
Mike

qwertyd10n · Post by **qwertyd10n** » July 4, 2011, 11:31 pm

Hey all,

So, I had the truck out and put quite a few miles on it today... and I have to say that the new drivetrain seems all good. No whines, groans, vibrations, or any other oddities.

I had it up to highway speeds quite a bit and as I got more confident with it, I starting rooting on it to see if anything felt off. But I'm happy to say I found nothing.

On another good note, the "new" transmission seemed to shift really good with the 75W90 synthetic in it.

My new seat feels as good as it looks, it was awesome having a radio and a tach, the turn signals cancelled for both right AND left turns, and my new smaller steering wheel worked really well... all and all, it was a very gratifying day after quite a bit of work over the last six months.

Now I think it's time to pull the 352 in anticipation of getting the new 445 soon!

Cheers,
Dion