Driveshaft backwards ???

[1976gmc20]

Look at picture #17 in this Ad:

https://denver.craigslist.org/cto/d/...879021427.html

I have never (until now at least) seen a driveshaft installed with the slip joint / splines at the differential, but always at the transfer case/transmission end.

Makes me wonder what else is wrong with this pickup? Seems pretty over-priced for how rough it is, no grill, etc.

Oh, and this can't be a 1970 unless the front has been changed. Has to be a 71 or 72 with the turn signals in the bumper. And of course it's not a "K-20" either.

[rpmerf]

There are several things about this ad that scream walk away.

Is it normal how much the bead and cab seem to be leaning toward the center?

[1976gmc20]

Originally Posted by rpmerf

There are several things about this ad that scream walk away.

Is it normal how much the bead and cab seem to be leaning toward the center?

It's probably just the bed mounting that's screwed up.

I wasn't really interested anyway. I'm looking for a nice 88-95 K2500 but would also like to replace my rough 88 K1500 x-cab with an older K-20 for a "ranch truck". But a short stepside 4x4 is always interesting

[A1971Blazer]

the slip joint is fine there...the rest of the truck is a cobbled-up mess

[special-K]

A friend bought a put together K/20 (late-70s chassis/'68 body) and it had the driveshaft in backwards. His had a 2pc driveshaft and it kept pushing the carrier bearing out until we corrected the driveshaft. It's not good to have the driveshaft in that way. There are issues that result in improper articulation.

This truck isn't awful and by what I see trucks going for it's not out of line on price. It's just a cool old truck someone needs to buy and get to work on. There are only ever so many unmolested clean survivors out there. I thought taking trucks like this and turning out a gems was what we do. This one is ready willin' and waiting

[1976gmc20]

Well, if I was going to settle for another half ton again, there's a long wide 1970 K-10 about a hundred miles from me with a 292 straight six for $2500. Pretty much original, only thing really wrong with it is the door sills are rusted out and need some serious repair. I dunno how much that costs; I can fix the mechanical stuff but not body restoration. I just want a wood truck not a show truck but I don't want my feet hanging out either

Out where I live, we have a heck of a time keeping 15" tires on a half ton 4x4. I guess I should try to find some new bias 7.00-15 because we never had much trouble with them even way back up on the gravel in Colorado, but the C range radials just keep getting ruined.

[1976gmc20]

I actually was looking for a nice 88-95/98 K2500 regular cab long bed that we could make good enough to take long trips with a little camper, but of course I see all these cool old trucks that catch my eye

I have a wood truck, the 89 K1500, but it is an ext cab and with the IFS it is a pain in tight places. It's great in that it's rough enough that I don't mind scratching it but I just don't think it's worth fixing up to be a long distance road truck. I'm going to need something road-worthy to go clean out my mom's house one of these days. The little car ain't going to be able to haul all the stuff wherever it needs hauled.

So now I find the perfect wood truck down in Denver, an 82 GMC K-20 with a new engine for $2250! Yeah, it has some rust. Claims to have the NP205 TC which I thought they only put in one tons after 1980 ???

[powerdriver]

Originally Posted by 1976gmc20

. Claims to have the NP205 TC which I thought they only put in one tons after 1980 ???

I have an 84 3/4 with a 205 in it

[1976gmc20]

Originally Posted by powerdriver

I have an 84 3/4 with a 205 in it

Okay, well that expands my options!

So half ton 1981++ had aluminum chain drive 208, but 3/4 and 1T had 205 ?

[special-K]

Not sure how it worked, but there were NP205s in some K20s and K30s then there were either with NP208s. I know when full-time was offered you got the NP203 or w/o it you got NP205. I've had an '84 K20 with TH400/NP208 and the CCUV K30s got them, too... except the ambulances

[1976gmc20]

Originally Posted by special-K

Not sure how it worked, but there were NP205s in some K20s and K30s then there were either with NP208s. I know when full-time was offered you got the NP203 or w/o it you got NP205. I've had an '84 K20 with TH400/NP208 and the CCUV K30s got them, too... except the ambulances

I've had (I think...) three pickups with the NP205: 1973 K-20, 1980 K-10, 1971 K-10 (in that order). My 1991 Suburban has the NP208 and it's never been any problem but I'd be scared to pull the stuff I pulled with the others (like semis and bulldozers), for fear the aluminum case or the chain would give out. My understanding up to this point was that the NP205 went away in 1981. Maybe 1981++ the automatics got the 208 and the 4 speed got the 205 ???

I think my 1973 K-20 was one of the last automatics before they switched to the NP203 full time. I never could see the point in that, although the Jeep we got a few years ago with the full time position (NP242) works great. At least it has the option for 2wd although there's no hubs so everything keeps turning anyway.

If I were totally rebuilding a rig and money was no object, I'd want to do one of those 203/205 "doubler" three-speed transfer cases, with something like nearly 6:1 reduction with the TC alone, plus low gear from the transmission

[special-K]

Full-time was an option, or 4spd and auto part-time were options. I've always liked older 4wds and back when full-time was offered I paid no interest and thought they all went downhill with that newfangled gimmick. That was until a good friend got a new '79 K20 with TH400/NP205. And that was one fine truck to be respecting. Not sure the rhyme or reason behind which t-case was used, but about the same time the NP208 came out GM started offering light duty 3/4t trucks with semi-floating rear and all those I've seen had the NP208. Jimmy's '79 had a full-floater and my friend's with the '68 is on a '79 chassis w/NP205 and full-floater. The NP205 was offered through '91, although only on R/V models, and only on 3500s... I believe.

[1976gmc20]

I forgot about the semi-floating deal. That's another thing to be looking out for, and the one I found in Denver has hubcaps so you can't tell. I'm not really ready to buy right now anyway; first I need a good pickup to go drag it home.

I was thinking that all automatics from about 1974 - 1979 got the NP203 full time, and I was glad my 1973 didn't have it. Actually, I was kicking myself within a few months that I hadn't gotten the 4 speed instead, after taking it out on jeep trails in the mountains. The only reason I traded it off for a 1980 K-10 was to get rid of the automatic, and try to get better gas mileage. It would hardly back up a hill anymore without putting it in low range, and I was living/working out in the woods and couldn't hardly put it in the transmission shop for a week. Or that's what I told myself at the time.

[special-K]

Yeah, I was under the impression they went all full-time with automatics and only 4spds weren't all those years up to '79, too. It's another reason I stayed back '72 or earlier. I guess in the '80s I had a friend who bought a local fire house's brush truck. It was a '73 K10 with a 350/TH350/NP205.

[Killer Bee]

Originally Posted by 1976gmc20

Look at picture #17 in this Ad:

https://denver.craigslist.org/cto/d/...879021427.html

I have never (until now at least) seen a driveshaft installed with the slip joint / splines at the differential, but always at the transfer case/transmission end.

Makes me wonder what else is wrong with this pickup? Seems pretty over-priced for how rough it is, no grill, etc.

Oh, and this can't be a 1970 unless the front has been changed. Has to be a 71 or 72 with the turn signals in the bumper. And of course it's not a "K-20" either.

flipping the drive shaft is a 'wheeler' trick..

puts the weaker tube end further from harms way and the stouter solid yoke end down closer to the trail..

[1976gmc20]

Originally Posted by special-K

Yeah, I was under the impression they went all full-time with automatics and only 4spds weren't all those years up to '79, too. It's another reason I stayed back '72 or earlier. I guess in the '80s I had a friend who bought a local fire house's brush truck. It was a '73 K10 with a 350/TH350/NP205.

I think they switched to full time on the automatics sometime mid/late-1973 model year or maybe 1974. I ordered mine in January 1973 and got it in late May or early June (4wds were hard to get back then, not everywhere like now). I had a heck of a time getting the correct new front driveshaft some years later, since the parts books couldn't handle the automatic and part time 4wd.

Mine was K-20 350/350/205, medium olive with white cab top. It had the 16" split rims and 7.50-16 8 ply tires, and the massive full floating hubs front and rear. Except for the TH350, it was a perfect pickup. Going up hills was usually fine, but going down steep slopes you had to use the brakes pretty hard even in low range.

Somewhere buried in a box I have some pictures.

[1976gmc20]

Originally Posted by Killer Bee

flipping the drive shaft is a 'wheeler' trick..

puts the weaker tube end further from harms way and the stouter solid yoke end down closer to the trail..

Strange. It looks weaker that way, plus the splines would be more down in the mud and dust.

[special-K]

I never heard that trick. Sounds like mythology to me anyway. The driveshaft needs to be strong enough or break no matter which end. I have faith in GM's designs... now time tested. All I know is it causes binding that doesn't occur when installed properly. Maybe he needed a new carrier bearing, but it hasn't popped out since it got corrected and it has been like 10 years. He still has the truck. Also, I wouldn't want the slip-yoke further down in the crud

[Killer Bee]

Originally Posted by 1976gmc20

Strange. It looks weaker that way, plus the splines would be more down in the mud and dust.

the tube is the weakest point and larger diameter makes it more vulnerable closer to the ground..

one scribe from a rock it opens like a beer can, the other end stands a better chance of surviving the same obstacle..

whether y'all believe it works or not, they still do it.. buddy of mine does some hardcore crawling and he told me about this years ago..

point is, that alone wouldn't steer me from looking at that truck if I was interested in it otherwise..

very likely the drive shaft was turned that way on purpose and not uncommon in the wheeler crowd..

[1976gmc20]

So the oak dashboard and sunroof probably have some off-road advantages as well ???




Really, I'm looking for:

1) a very nice 88-95 single cab long bed K2500

2) an old K-20 with a four speed - but a short stepside K-10 with a straight six and a four speed would sure be tempting

I've got too many vehicles, most of which don't exactly fit my needs. At some point I'd like to buy exactly what I want and then sell off the ones I don't want/need anymore.