Attention: TDR Forum Junkies 
Ok, I've searched the forums, the internet and spoke to various people about what to put behind my CTD. I was all set to convert from the original TH400 to a Dodge NV4500, until I found out, that even this stick transmission can have issues with torque (assuming the 5th gear nut issue has been fixed). I learnt that the stock torque input on the NV4500 is only about 450ft/lb and even mild BOMBing will exceed that.
I learnt to drive in a stickshift and love them for control and simplicity, but now I'm approaching my mid-life crisis
, I've also got to like the convenience of an automatic and ease of standing starts.
My goal is incrementally BOMB the CTD to 800ft/lbs and whatever HP the P7100 governor will provide from a 3000 GSK and upgraded valve springs, so starting out with the right transmission is going to be critical.
For the t-case, I want to swap the NP208 with an NP205 for strength. The rest of my drivetrain is set up for 9400lbs GVW: full float 14 bolt with detroit locker in the rear, FF D60 with LSD in front and monster driveshafts. The chassis is the military spec 30% thicker and stiffer version, so it won't twist in a hurry and sadly the Dodge Dakota that ran in the back of me during heavy snow found that out the hard way - his truck had over $10k of damage, and I just had to crank the bumper out with a come-a-long. My M1028 weighbridged at 4980lbs, so the Cummins will probably bring it up to about 5200lbs or thereabouts.
The truck is driven about 15% on 4x4 trails the local mountains (not rock crawling though) and the rest is mixed freeway, 55mph roads and lanes. I also love to outgun the odd "Passed and the Curious" in my camoflaged pickup.
Should I be considering an automatic on steroids or is it possible to re-engineer the NV4500 for more torque handling? What about going to a Spicer or Eaton transmission?
Is it more a question of just being careful with the NV4500 - I've never been one to stomp on a transmission, but I do like to drive them firmly.
Since this is a conversion on a CUCV M1028 5/4 ton military pickup, I'm very flexible on the final choice.
I learnt to drive in a stickshift and love them for control and simplicity, but now I'm approaching my mid-life crisis
, I've also got to like the convenience of an automatic and ease of standing starts. My goal is incrementally BOMB the CTD to 800ft/lbs and whatever HP the P7100 governor will provide from a 3000 GSK and upgraded valve springs, so starting out with the right transmission is going to be critical.
For the t-case, I want to swap the NP208 with an NP205 for strength. The rest of my drivetrain is set up for 9400lbs GVW: full float 14 bolt with detroit locker in the rear, FF D60 with LSD in front and monster driveshafts. The chassis is the military spec 30% thicker and stiffer version, so it won't twist in a hurry and sadly the Dodge Dakota that ran in the back of me during heavy snow found that out the hard way - his truck had over $10k of damage, and I just had to crank the bumper out with a come-a-long. My M1028 weighbridged at 4980lbs, so the Cummins will probably bring it up to about 5200lbs or thereabouts.
The truck is driven about 15% on 4x4 trails the local mountains (not rock crawling though) and the rest is mixed freeway, 55mph roads and lanes. I also love to outgun the odd "Passed and the Curious" in my camoflaged pickup.
Should I be considering an automatic on steroids or is it possible to re-engineer the NV4500 for more torque handling? What about going to a Spicer or Eaton transmission?
Is it more a question of just being careful with the NV4500 - I've never been one to stomp on a transmission, but I do like to drive them firmly.
Since this is a conversion on a CUCV M1028 5/4 ton military pickup, I'm very flexible on the final choice.
