Manual to auto conversion

[Chris H]

So I heard that you could convert in a 79 from a manual to 47rh/re auto. Any experience with this?

 

[CSFJ]

Never heard of swapping in a Chrysler trans to a GM. As Dodge/Chrysler weren't really known for dependable transmissions during the last couple of decades, not sure how solid of an idea it is, especially with the available overdrives like a 4L80 from GM, which would make for an easier swap.

 

[Chris H]

Never heard of swapping in a Chrysler trans to a GM. As Dodge/Chrysler weren't really known for dependable transmissions during the last couple of decades, not sure how solid of an idea it is, especially with the available overdrives like a 4L80 from GM, which would make for an easier swap.

I wish I could remember who told me this. They said that both Chevy and Dodge were using the same transmission for a while. So the swap was pretty easy. But I don't remember the exact model number of the transmission. I had a 99 Dodge Cummins, and I thought he said that it was the same transmission. So that is what I looked up for the number. I may look into the one that you recommended. See what all it would take. Thanks for your input.

 

[DoubleDingo]

NP435?

 

[CSFJ]

They used the same manual transmissions, or versions of them from New Venture for a while, (nv3550, nv4500) but never automatic transmissions.

 

[Chris H]

NP435?

That could have been it. Sounds closer than what I found.

 

[Chris H]

They used the same manual transmissions, or versions of them from New Venture for a while, (nv3550, nv4500) but never automatic transmissions.

Yeah, I kind of thought it sounded odd. But that's why I asked!

 

[Chris H]

Yeah, I kind of thought it sounded odd. But that's why I asked!

Actually, he could have been referring to a 5-speed manual transmission. So that would make sense! Cool, thanks for your help.

 

[Snoots]

Why?
You'll just make it easier for a millenial to steal it.

 

[Chris H]

Why?
You'll just make it easier for a millenial to steal it.

LOL, that's true! But I also have a switch for the electric fuel pump. That's too much work for them!

 

[DoubleDingo]

Why?
You'll just make it easier for a millenial to steal it.

When I take the 3 speed out of Crusty, it is column shifted, but the stuff going in is all floor shifted. The Ranger OD and SM420. I am going to leave the column shift handle on the column to really mess them. Two sticks coming out of the floor, and one on the column. It'll be great!

 

[CSFJ]

When I take the 3 speed out of Crusty, it is column shifted, but the stuff going in is all floor shifted. The Ranger OD and SM420. I am going to leave the column shift handle on the column to really mess them. Two sticks coming out of the floor, and one on the column. It'll be great!

If you use a 4 spd Saginaw box instead, I have heard of it being installed to use the column shift to run the forward gears, and having a separate lever on the floor for reverse. This would leave two shifters on the floor, along with a functional column shift too.

 

[DoubleDingo]

If you use a 4 spd Saginaw box instead, I have heard of it being installed to use the column shift to run the forward gears, and having a separate lever on the floor for reverse. This would leave two shifters on the floor, along with a functional column shift too.

I've been planning this mod since I got the truck in 2015. Have been enjoying three on the tree since I hadn't ever driven a vehicle with it until I bought this one. I want the heft and gearing of the SM420. I do have a Muncie M21 I believe, but it needs a rebuild, and I don't want to put it in a 3/4 ton truck.

 

[Charlie]

 

[trukman1]

So, getting back to the title of the post, how hard is it to switch from manual to automatic? What components would be needed to get from the donor vehicle to do the swap? I once did a SM465 (mine) to a TH400 (other guys) by pulling trucks side by side. Had to swap radiator, speedo gear, pedals, columns, etc. (I may have just answered my own question) but maybe we should tell OP what he'll need to get to do the swap so he doesn't have to go tracking down odd parts later which can be a royal PITA!

If I'm off track on post I'm sure someone will be quick to point it out...LOL!