CUCV to K5 drivetrain swap

[ScottyTightdog]

I'm considering buying one of the CUCV M1028 military trucks and swaping the Dana 60, 14 bolt, Th400, and NP208 all into my 72 K5. I'd like to hear from those who have done the swap and any input on what problems or snags I might hit along the way. It seems like a easy way to have a bombproof K5 but I would definitely like to hear from people much more knowledgeable than myself. Thanks in advance

[cleszkie]

Should be a relatively straight forward swap. May have to adjust tranny/t-case cross-member location, but that is easy. As far as being bomb-proof, all of the CUCV components are good. But there are two things that could use improvement.

1) The NP208 t-case is a chain driven case with an aluminum housing. Chains stretch and break, and aluminum housings crack. A gear driven, cast iron cased NP205 would be a stronger alternative, but the low range might not be as deep as the NP208.

2) The CUCV 14 bolt might be equipped with a "Gov-Lock" limited slip. These are good units when new. But when they have been worked hard over many years, they have a tendency to have the clutch plates disintegrate and drop pieces into the diff fluid. Had this happen to me.

Overall, I think you have a pretty good plan with this drivetrain swap.

[Killer Bee]

they weren't really bomb-proof in the beginning, just so woefully under powered and slow that made them last..

not bad stuff to seek for transplant, but as cleszkie mentioned, there are better component choices..

good luck!

[ScottyTightdog]

Hey, thanks for the replies and thats very helpful information. So give me your opinions on the best other swap options.

[Killer Bee]

off the top of my head, seems like 1 ton trucks from mid/late 70s had some popular robust axles and drivetrain components..

hopefully some guys that have done this will chime in with their build threads..

might have some luck searching through here and other 4x4 forums for build upgrades..

steel soldiers and other .mil vehicle sites might have some good reading for your research..

If I land on something I'll share, good luck!

[rayray767]

I bought the M1008 pickup to do just that . I had purchased it from a military base here in Columbus, Ohio a few months ago. Took like a month just to get a civilian title for it anyways. I wanted to drive the truck around a bit to be sure all components were working correctly. The 39,000 mile truck seemed to run and drive perfectly 6.2 motor ran good as well. The one problem was it’s super slow but definitely built to pull down a house lol.
It to has the 400,208 & the 456 gears. Thang is I’ve been using the hell out of it! I’ve changed all the fluids in it and the dry rotted tires. If something happens to the 6.2 is probably when I’ll do the swap.
Till then I’m
Subscribed to this post.

[rayray767]

Good old Sarge is what I call this truck.

[truckster]

CUCVs were fine for driving off-road, but if you had a long road march on the highway they got tiring pretty quickly.

[Killer Bee]

^ yep, here's a shot at the suncheon toll plaza