Howdy,

Leaving Nov 2 to pick up '76 f250 4x4. Curious, has anyone out there installed an overdrive with the divorced np205 setup. If so what brand of kit or in a nutshell what were the mods required (driveshaft length changes. brackets, etc.)

Thanks

Bob

 

Bob,
I installed a GearVendors OD unit onto my '74 hi-boy's divorced transfer case when I built my new 410 and went thru the tranny and transfer case last year. I've got about 10,000 miles on it so far, and it's really an asset. It cuts back on engine noise bigtime at highway speeds, and has become essential for letting me use 3rd/OD to climb hills with the slide-in camper aboard, and I'm sure that MPG's are helped but that's hard to tell with a new hotter engine installed at the same time.
The install took a bit of fussing, but pretty much just a matter of wrenching. I did fabricate an extra bracket to restrict the motion at the rear of the OD, because it cantilevers off the transfer case and I could feel "something" moving around under hard acceleration. I used a driveshaft carrier bearing bracket with its rubber sleeve sans the actual bearing, then braced it to the frame with a piece of rectangular tubing. The driveshaft shortening was done by my favorite machinist after I completed the install and measured, and we dug up a u-joint that allowed using the Ford driveshaft slider yoke with the GM-size output yoke on the OD. Other than that, GearVendors provided everything along with good tech advice. The instructions provided were a little convoluted, so unless they have updated them you will find that you need to read thru ALL sections to fully understand everything that needs to be done, even tho they don't appear to relate to your actual install at first glance.
Overall a tad expensive, but I'm really happy with the results.
Steve

 

Thanks,

I like the sound of that and you make it sound fairly straightforward. I'll have a look around to come up with some pricing. One thing though, what would you estimate was the time (roughly) to complete the install?

Thanks again,

Bob

 

You have to understand that I am a compulsive ponderer, studier, and planner, so it took me some longer than it would have had to. But I would estimate that it was probably the equivalent of about 6 hours by the time I did the wrenching, routed the wiring, and made up the electrical connections. I had to hit up GearVendors for a right-angle speedo drive due to limited clearance to a gas tank on the driver's side, so that took a couple of days to get to me. And I just remembered that a 4-wheel-drive cutout switch wouldn't work on my install. (That's to keep you from using the OD while engaged in 4x4 since the OD is only connected to the rear axle.)
Be sure that you are sitting down when you start price-checking, as it was about $2600 last I looked. You can get a 10% break by joining the Camper's World "Presidential Club" for $20 or so. Also the synthetic grease that is recommended came from GM to the tune of $23/quart as I remember, and it takes two of them! When I changed oil in it this year I used RedLine MT and that seems to work just fine.
Steve

 

You don't say what transmission you will have, but check out US Gear. Their unit bolts to the back of (most) transmissions, and that way, it doesn't matter whether you are in 2 or 4 wheel drive.
You might have to move the T case back a little, depends on mid driveshaft length.