Tranny Trouble

Solomon Grundy · Jul 23, 2004

So I believe my manual 3 speed tranny is going, and I want to replace it with a NP435, I would like complete input from other guys who have made the swap, how difficult is the procedure, what will I need, what will I need to cut, to buy, and maybe modify. I currently have the 170 straight 6. I am all ears, please help.

Thanks guys

Broncoholics · Jul 23, 2004

I did this set-up on my 68. I had to make a custom cross brace for the 205 t-case since it was attached to the 435 I decided to use it. If you keep the Dana20 then you should be OK to reuse the stock one but you need an adapter between the D20 and 435. Its best to have at least a 2" body lift otherwise you have to cut a large hole in the floor tunnel for the shifter to come thru. Also depending what t-case you use the drivelines might have to be modified longer or shorter.

Toby the Dancing Bronco · Jul 28, 2004

I bought the 435, adapter, floor tunnel cover and clutch from Toms a couple years back. The thing that made the swap the easiest was a lift that picked up from the out side. The next best thing was a plasma cutter. The next best thing was a real-honest-to-goodness transmission jack. The best part of the swap was that I have a friend who has all those things and didn't mind helping me. 8 hours start to finish.
Hardest part was hooking up transfer case shifter.(we forgot to put it on, and had to drop the whole assembly again to do so. cost about an hour.) Tom's instructions were pretty well written and easy to follow. With my particular swap, there was no need for any shaft or crossmember mods.
I wouldn't spend a(nother) nickle on the 3 speed, though. <_< Hope it goes well.

Solomon Grundy · Jul 30, 2004

Ok Guys I love the input, but I need to know for sure if all I will need is the adapter from D20 to Np435, what about bellhousing on the 170 I-6? Will it fit in the crossmember and can I do it with out body lift? ALso the prices?
Thanks for all the information

Toby the Dancing Bronco · Aug 2, 2004

Most "complete kits" include the tranny to t-case adapter that you will need, as well as the spud shaft to make the connection between the two. I paid about $1,350 for the whole set up (clutch parts, tunnel cover, 435, adapter and necessary gaskets. The new adapter was partly needed due to the fact the 3 speed is longer than the 435, and partly due to bolt pattern issues, as I recall, but I have broken other parts since then, so I don't recall if those are the only reasons. Some places make adapters or sell new, but Toms' adapter was a 3-speed adapter converted for the purpose. Cheaper, and there have been no problems so far. Hope it helps!