Transmission Swaps

[jeepjoe43]

Some of you may already know I'm planning on swapping a SM420 to replace my AX5.
Well, it's time to at least start doing a little homework.
I know there used to be a kit, but now it's discontinued.
Some clutch parts and a NP231 adapter are still available from Advanced Adapters, Novak may have offerings too.
The 420 I'm going to use is currently adapted to a D300 (AA spud shaft type) behind a 2.0 Pinto.

I've read a number a articles, but I like as much info as I can get.
Just like to hear any experiences or advice putting this box in a YJ, greatly appreciated.

 

[Gilaguy23]

Cant say I'll ever have one in my 91 but Ive had several trucks that ran either that or the NP435. IIRC, there are 2 different compound low ratios offered. Best I can say is brutal strength, heavy, a bit long throws between gears and you wont win any drag races shifting fast. My first 4x4 was a 75 F250, 360, Np 435 205 T case and D 60/D44HD up front. Id give my left one to find another in like shape. New trucks are great with all the gizmos but that thing was a the real deal. Good luck with the swap, should be indestructible once done.

 

[jeepjoe43]

Cant say I'll ever have one in my 91 but Ive had several trucks that ran either that or the NP435. IIRC, there are 2 different compound low ratios offered. Best I can say is brutal strength, heavy, a bit long throws between gears and you wont win any drag races shifting fast. My first 4x4 was a 75 F250, 360, Np 435 205 T case and D 60/D44HD up front. Id give my left one to find another in like shape. New trucks are great with all the gizmos but that thing was a the real deal. Good luck with the swap, should be indestructible once done.

Loved the 420 in my GPW, and I Like the long throws (one the reasons I hate the AX5).
Granny to dash, apologizing to my passenger for Reverse, being able to "feel" through the gears without a clutch, even granny.
The 420 has the lowest compound 7.08, and it was an axle smasher.
This is the only swap I wanted for the YJ, but couldn't do bc of the weak axles.
So it wasn't part of the original plan to just build a simple trail rig. Plans change.
Originally had a $5k budget for the build too, that's turned into a Continuing Resolution.
And Thanks!

 

[Gilaguy23]

A budget and jeep ownership...ha,hahahahahahah, you know how that turned out I honestly think Id be close to a millionaire if it wasn't for trucks,bikes and jeeps.....er.......and well women too I suppose.

 

[jeepjoe43]

Been absent from the Jeep world for about 20 years and thought I could pull off a budget, she had other plans.
Just been one link in the chain after another...

If I could only get back just the money I've wasted!