Common Trans swaps....?

[cmitchelli]

Curious to know what are some common trans swaps for these trucks. I see mention of SM465 and nv4500. I'm a standard trans kind of guy and was curious to know if a SM420 would handle the M715.

[myJEEPisAfatty]

The stock transmission is almost identical "gearing wise" to the sm465 and 420.

So yes it would hold up fine.

[osut362]

sm420 is plenty tough. i have a '54 chevy 3 yard dump truck that still is a working truck. the trans is an sm420. but, internal parts are getting hard to find new i hear. i've never had to buy any however.....al
sm240 differs from sm465. 420's 1st gear is lower and reverse is left and then down.

[cmitchelli]

Cool, I'll be on the lookout for a SM series trans...

[jeeper]

Why are you asking?

What engine are you planning to bolt it to? Do you have a transmission in the truck now?

The Muncie transmission is fine if you are bolting it up to a Chevy engine. I have never checked to see if it could be adapted to another engine.

Are you planning on driving it highway speeds? If so you may consider swapping in an overdrive transmission. This would also make a transfer case swap pretty likely because the stock case gets hot over 50 mph.

[Alaska hunter]

the Sm420 is lower geared but if you want to run a married transfer case I don't think the sm420 adapts to any of them were as the sm465 adapts to np205 203 208. but if you want a divorced case the sm420 will work. its first gear is 7.0 were the sm465 is 6.55

[randyscycle]

If you are planning on keeping the stock divorced transfer case arrangement, then just about any 2WD transmission will work. The output yoke to the jackshaft is all you'd need to fabricate, depending on what you use.

I've seen (personally) SM420's, 465's, ZF's, Borg Warners, Spicers, and a variety of automatics in front of the NP200 or 205's. The nice thing about the M715's is their easy adaptability.

That said, personally, if I were to do a manual transmission I'd most likely use a Spicer 3053a out of a Deuce.

[cmitchelli]

Thank you all for the input. I do not have a 715 yet, and am doing my homework before I dive into this and find that I've bitten off too much. I want to build a truck with a modernized drive train to (heaven forbid) keep up with traffic. I'm thinking a smaller GM V8 for a powerplant. Would like a diesel, but that could get costly.... Doug S.

[m715]

Ah if your in the research stage then sky is the limit

If your looking for highway driving you will probably want to replace the original NP200 transfer case as it tends to heat up at highway speeds. BUT that just means you can pull a full drive train from a modern vehicle for the swap.

The small block chevy is a good swap, with many parts and options available. I would agree with randyscycle, the spicer 3053A out of a Deuce is a great choice, strong trans w/OD, cheap, parts readily available and you can run it with any divorced transfer case you want.

I wouldn't discount a diesel swap. The cummins swaps are becoming fairly standard and a 1989-1993 1st gen dodge cummins 3/4 4x4 would be a perfect candidate for a swap. Buy a complete truck, it will get you everything you need engine/trans/tcase/1 ton axles... You just have to find the right deal.

Good luck with the research and the hunt for a M715!

[Barrman]

Yep, go diesel with a complete drive train donor vehicle. OD sure is nice.

Don't plan on a gas engine getting better than 12-13 mpg no matter what gears and transmission you end up behind it. 8-10 will be more like it. Diesel will vary depending on 6.2NA(15-17), 6BT(18-22), 4BT(20-25)