Cab Swap Guidance - M1028

[RallyRebel]

Been a while but I'm finally back to working on my M1028 that got rolled while in transport on a trailer, crushing the cab. I picked up an '86 Silverado parts truck some time ago, good straight 1/2 ton 2WD with no drivetrain, as a donor. So, having never performed a cab swap before I'd appreciate ANY suggestions, tips or insight for doing the swap. I'm using a 10-ton crawler crane for lift (I have big toys!) and a spreader for the straps to lift from underneath so I don't stress or deform the new cab. I'm thinking this will be a good swap as I'll be rid of all the 24V stuff and also pick up factory A/C. I'm relocating batteries (Optimas) under the bed too for cleaner underhood and more room for A/C plenum. Thinking about going with urethane cab bushings, thoughts on that?

Thanks for any responses! And I did use search on this but didn't find much specific to my need.

- Joe

 

[dependable]

I would prep new cab (and other sheet metal when it is off ) and paint with Chassis Saver, P O R 15 or other good rust slowing process while you have it off the truck. New cab mounts seem like a good idea, as long as they fit right.

 

[K9Vic]

I read this and was thinking that this was the incident from several years ago and checked your old post and see it is. That was like 5 years ago and interesting that you are now getting to fixing it. Hope it goes well and I am sure you will find the help you need.

 

[trukhead]

The radiator support mounts on both sets I have removed have been seized and the nut on the bottom of the mount was a bugger to remove but it is possible and the top of the bolt must be held regardless and it is a another booger to get a wrench on from the front through the grill.
Disconnect the stuff from the cab and lay it over the engine. I am curious if the civi cab has the same firewall as the mil unit.
95% of the 24 volt stuff is in the engine compartment in the charging circuits, starting circuits and the glowplug resistor bank. Get the wiring diagrams from the manuals and study them until you understand them.
Have Fun!

 

[RallyRebel]

lol, yeah, i've got WAY too many projects! Fortunately donor truck is a florida truck, no rust, and PO prepped well for paint before deciding to part out so it's straight and in primer. Hopefully 1/2 ton cabs mount the same as CUCV cabs! Planning on painting desert and markings for MacDill AFB. It'll be nice to finally have this rig back on the road.

 

[RallyRebel]

thanks trukhead! I'll doc with pics for FW comparison, look mostly same with obvious exception of brake MC, fuel filter and A/C plenum. Going with Racor spin-on fuel filter, frame mounted. Like the 924's in the background! My pics would have 5 XR4Ti's, lol!

 

[ranchhopper]

You will have to cut part of the floor out of a 2WD cab to fit on a four wheel drive chassis. The trans tunnel needs to be cut you can see the indentation where it has to come out use the floor plate in the original cab to cover it up it bolts on.

 

[trukhead]

thanks trukhead! I'll doc with pics for FW comparison, look mostly same with obvious exception of brake MC, fuel filter and A/C plenum. Going with Racor spin-on fuel filter, frame mounted. Like the 924's in the background! My pics would have 5 XR4Ti's, lol!

Ha Ha, I should have pointed the camera east off the cab, you would have seen 2 more 924 turbos and an xr4ti!!
I have one more xr4ti with:
stainless turbo header
lowering kit
big brakes
shock tower brace
super computer
limited slip rear end
Borla wheels
tires to match wheels
3 inch stainless exhaust
super duty clutch
a bunch of other stuff to make it a fast rally racer
gonna install a non electric C-4 tranny in place on the 5 speed

my bad for hijacking the thread but i couldn't resist.

The truck in the picture is the one the cab is coming off of.

The truck had the Rosocmen 12 volt conversion. I think one can eliminate a whole bunch more wire under the hood.
The truck itself operates on 12 volts. The starter, glowplugs, nato cable, trailer lights and the series charging system of 12 volts + 12 volts are the only 24 volt part of the system. Study the electrical schematic and it will come clear.

 

[trukhead]

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