3OTT/ four wheel drive truck?

[1971 cheburban]

Has anybody seen a truck with a three on the column and four wheel drive? I've seem a couple fords(yuck) with a 300-6, 3 on the tree and they were 4 wheel drive, but I've never seen a chevy 3 on the tree four wheel drive, not only in our years but 73-87 either, I've seen the autos and four speed but never a 3 speed, if anyone has seen one please comment Id love to hear about it

[Already Gone]

I know I've seen one once but cant remember where. I look at Craigslist, Ebay and other sites looking for trucks and that is probably why I don't remember where I saw it. Like you I thought it odd but as i'd never seen that power train combo before on one of our trucks.

[mrein3]

Originally Posted by 1971 cheburban

Has anybody seen a truck with a three on the column and four wheel drive? I've seem a couple fords(yuck) with a 300-6, 3 on the tree and they were 4 wheel drive, but I've never seen a chevy 3 on the tree four wheel drive, not only in our years but 73-87 either, I've seen the autos and four speed but never a 3 speed, if anyone has seen one please comment Id love to hear about it

When I first bought my truck it was a 4 wheel drive, three on the tree. I drove it that way from 1994 until December of 2001. To this day I still say the tranny swap to a th350 was the best "upgrade" I've ever done to the truck.

The clutch was nice for shifting in and out of 4 wheel drive. I miss that. With my th350 you have to come to a complete stop and put it in park to shift the transfer case. With the clutch you just jam the clutch to the floor and shift away while rolling. My beef was they should rename the 3 OTT to the jam-o-matic. I tried everything to keep it from jamming. Adjustment. New bushings. Google this site, write down all the things people have posted to keep it from jamming, and you will have the list of things I tried. I even paid a shop once to adjust the shift levers. In a round about way they guaranteed their work until the end of their driveway which is about how far I got before the next jam.

Actually it didn't jam all the time. Just when it was not a good time. Like at a busy boat ramp or in creep and beep, bumper to bumper traffic.

Sorry for the tangent. 3OOT/4wd trucks do exist. I posted the manual tranny for sale on this site and sold it to a guy in Iowa who needed to replace the one in his truck so GM built at least two of them.

[Stocker]

Originally Posted by mrein3

With my th350 you have to come to a complete stop and put it in park to shift the transfer case.

As long as my hubs are locked in, the only time I have to stop is to engage 4LO. No problem shifting from 2HI to 4HI (and back) on the fly -- just momentarily back off the throttle as you shift the t-case.

As to 3OTT in a 4WD, the main reason I see for not having it is the same as any manual 3-speed -- no granny low like in many 4-speeds. Yeah, I know the t-case has a low range, but a crawler gear in the trans is nice to have also.

[KyFarm]

My truck came originally as a 6 cyl, 3OTT, 4 x 4.

When I bought it: 350, 3 OTT

Now, 402, TH350, 4 x 4

[blue 72 gmc 4x4]

Mine still is a 3OTT 4x4, although the 6 was replaced years ago with a 350. Now I have a 383 in it. Everyone says I should put an SM465 in it which would be a good idea...but I like that 3OTT!!

[Stocker]

One thing I always like about 3OTT is how easy it is to 'rock' the vehicle (switching back & forth from first & reverse) when you get stuck.

[1971 cheburban]

Holy shnikes guys, the only ones I've seen are those stinkin fords, thanks for all the info, now a couple questions for transfer cases, what input shaft is a 205, like can you use a 350/400, 4 speed or 3 speed, or do you have to have different adaptors for each(auto or manual), I'm looking into a possible four wheel drive, I want to know if I get an auto(it has to be a four speed) can I just switch the crossmember need be and get a four wheel drive t-case, an the z-bar stuff, or am I going to have to hunt up a bunch of adaptors for the splines, also what is a good 4wd motor, just a good old 292- I was thinking about soiling one up or should I try for a big block, I just don't want a 350 like everybody else has, which isn't a bad thing, but a 396-sm465-205 and 3:73s would be nice, an a very fun piece, I know where a 72 is I might be able to snag but it has a 350, which I don't want, I don't know I'm just talking, just thinking, it's already a four speed, so I might jut get me a 292 or a 396, I know 396 is obviously expensive to build and run, but a 292 souped up wouldn't be much better but cheaper, plus it would be different, anybody got fuel mileage and specs on a souped up 292, just something tht has a little thump and sounds good, and anybody have headers for a 292, sorry for the rambling and taking this thread way off track

[mrein3]

Originally Posted by 1971 cheburban

Holy shnikes guys, the only ones I've seen are those stinkin fords, thanks for all the info, now a couple questions for transfer cases, what input shaft is a 205, like can you use a 350/400, 4 speed or 3 speed, or do you have to have different adaptors for each(auto or manual), I'm looking into a possible four wheel drive, I want to know if I get an auto(it has to be a four speed) can I just switch the crossmember need be and get a four wheel drive t-case, an the z-bar stuff, or am I going to have to hunt up a bunch of adaptors for the splines, also what is a good 4wd motor, just a good old 292- I was thinking about soiling one up or should I try for a big block, I just don't want a 350 like everybody else has, which isn't a bad thing, but a 396-sm465-205 and 3:73s would be nice, an a very fun piece, I know where a 72 is I might be able to snag but it has a 350, which I don't want, I don't know I'm just talking, just thinking, it's already a four speed, so I might jut get me a 292 or a 396, I know 396 is obviously expensive to build and run, but a 292 souped up wouldn't be much better but cheaper, plus it would be different, anybody got fuel mileage and specs on a souped up 292, just something tht has a little thump and sounds good, and anybody have headers for a 292, sorry for the rambling and taking this thread way off track

Lots of questions there. Let me see if I can help. In swapping from a 3-speed manual to a th350 I unknowingly became sort of an expert on the subject. At least with 67-72 versions of 4wd.

First of all, NP205 transfer cases. There are three versions.
10-spline input shaft 205s came behind manual transmissions. 3 speeds and 4 speeds.
28-spline input shaft 205s came behind th350s.
32-spline input shaft 205s came behind th400s. (As near as I can tell GM didn't use th400s in 4x4s until after 1972)
I have no clue why the three versions but that is just the way it is.

GM, when putting these in 67-72 trucks, made the transmission/adapter/transfer case (t/a/t) all the same length and the adapters bolt to the crossmember in the same spot. This HELPS you in building something in that to swap from one stock t/a/t to another stock t/a/t you simply swap the t/a/t, bolt it to the same cross member, and hook up the same driveshafts. GM was modular before anybody knew what modular was.

To swap from a manual to an auto, find a complete donor t/a/t. BEFORE you go and install them I would do extra stuff. These things are heavy and you don't want to have to re-do anything. EVERY used th350 to NP205 adapter I saw was cracked. I was able to buy a brand new one over the coutner at my GM dealer. Don't use GMpartsdirect or similar as this piece is heavy and shipping will kill you. My new adapter came with new oil seals in it. YOU WANT NEW SEALS IN THERE. The oil seal in the front of the adapter seals your th350's back just like the front oil seal on the front of your small block in the timing cover. You want a new drive sleeve. This part too is available from GM. This piece couples the transmission output to the transfer case input. It "floats" in there and mates with the oil seal. And like the harmonic balancer on the front of your small block, after 40 years of spinning around in there, develops a groove. And can leak. You don't want to re-do this job. Buy a new drive sleeve. If you do get your hands on an uncracked adapter, use it but replace those seals.

When I swapped my 3-speed manual I had access to a shop with a hoist and a tranny jack. I bolted my th350/adapter/NP205 together on the ground. I used a blue wrench to remove the rivets in the bottom of the crossmember. I VERY CAREFULLY chained the 3-speed/adapter/NP205 to a tranny jack, wheeled it away, lowered it as far as it would go, used a cherry picker to pick it off the jack, then set it on the ground. I then used the cherry picker to pick up the th350/adapter/NP205, chained it on the tranny jack, and reversed the process. I used bolts where the stock rivets were removed.

Oh. And I highly recommend sending the auto you settle on to a trusted transmission shop for a rebuild. I had them put in a shift kit too when I did my th350. I told them I was pulling a 3200 pound boat/motor/trailer and that thing still slams you back when it shifts gears.

And don't be afraid of a small block. I put a 383 in my truck in place of the tired 350 that I had with the 3 OTT manual. With 3.73 gears and stock height tires it does all the stupid pulling stuff I ask it to do.

The only draw back with 3.73s, stock tires, and a th350 is when going 70 on the freeway I'm turning 3200 rpms which is a little high. But since that doesn't happen much I've learned to live with it.

I hope this helps.

[undertaker72]

I had a burb with three on the tree and a straight 6 , and here is a another that he just had bought, http://67-72chevytrucks.com/vboard/s...d.php?t=636582

[71sixgun]

I have one, it a 1969 with one of the v8's (changed now) w/ 3oot, short bed, step side, 4x4.

[71 super]

I have had two that were 3ott 4x4 trucks, a 71 6 cylinder plain jane and a 72 3 ott custom deluxe, not uncommon, would figure there are more 4 speeds and three speeds than autos simply because of the 4x4 and most if not all 4x4 were bought to be used as farm/work trucks

[RANDY COX]

Let's see My dad had a 71 GMC that was 4x4 3OTT, I had a 72 4x4 Blazer that was 3 OTT
and a 70 Burb 4x4 with 6 had 3OTT.

[special-K]

3OTT was the standard transmission in all 67-72 K-models