gmc info

[JONSSTIHL]

you are quick on the replies thanks,

I'm not quite following you on the full floater compared to the ten bolt can you explain.

I will find out more about the half ton most importantly the price and having it up on a lift later but I'm thinking I may just put less weight in the truck and tow it with a trailer instead.

the half ton is in a lot better condition but I'm not too keen on the th350 tranny.
especially since it is on it's second rebuild, the shop screwed up the first one and the tranny lost third gear so they are doing the second rebuild on warranty.

I was hoping for an sm465

I think I just need a little more patience but I'm really itching for a truck

 

[GASoline71]

You won't find an SM465 in a half ton... 3/4 tons and bigger only... another bomb proff tranny.

The GM 14-bolt full floater is just that... a full floating axle. The axle shafts don't bear any of the weight... the axle tube does... Well technically it has a hub and a spindle and that is what bears the weight. You can actually remove the axleshaft without even removing the wheel from the truck. Only if it has stock hub caps on it though and not mag wheels where the center cap is non-removeable.

The 10-bolt is... well... a 10-bolt. A weak rear end. IMO they never ever should have found their way under a truck. TH350 is a good tranny but it has it's limitations. If it has A TH350... that means it prolly has a NP203 transfer case. If that is the case... it prolly has full time four wheel drive too... Maybe not. Some of the trucks in 1981 were getting auto locking hubs but they were garbage. If it is full time four wheel drive... you will hate it. Eats a lot of gas and is hell on front end parts. There are conversion kits... but I think they aren't the best option.

Gary

 

[chowdozer]

You won't find an SM465 in a half ton... 3/4 tons and bigger only... another bomb proff tranny.

The GM 14-bolt full floater is just that... a full floating axle. The axle shafts don't bear any of the weight... the axle tube does... Well technically it has a hub and a spindle and that is what bears the weight. You can actually remove the axleshaft without even removing the wheel from the truck. Only if it has stock hub caps on it though and not mag wheels where the center cap is non-removeable.

The 10-bolt is... well... a 10-bolt. A weak rear end. IMO they never ever should have found their way under a truck. TH350 is a good tranny but it has it's limitations. If it has A TH350... that means it prolly has a NP203 transfer case. If that is the case... it prolly has full time four wheel drive too... Maybe not. Some of the trucks in 1981 were getting auto locking hubs but they were garbage. If it is full time four wheel drive... you will hate it. Eats a lot of gas and is hell on front end parts. There are conversion kits... but I think they aren't the best option.

Gary

To add to Gary's post, a GM 14 bolt refers to the number of bolts holding the ring gear on, (as does 10 bolt or 12 bolt, which coincidentally often is the number of bolts holding the rear cover on). There were two versions, the full floater and the semi floater.

Here's a full floater. It's an Eaton, but it looks pretty much the same as a 14 bolt. Notice how there's a protrusion that sticks through the wheel with 8 bolts on it. Unbolt those and the whole axleshaft pulls out. The axle has splines on the end of it that fit into the third member. The axle actually puts it's driving force on the outside of the hub/brakedrum. The axleshaft only transfers power. The hub/brakedrum is supported with two tapered roller bearings on each side with two nuts that preload the bearings. Lots of load capacity. If you break an axleshaft, your wheel doesn't fall off.

Another pic

By comparison, here's what they called the semi floater. Notice there is no protrusion? Absence of the 8 bolts too. Usually these type of shafts are held in with C-clips accessible by removing the cover. Bad. If a C-clip breaks, the axleshaft wanders out. Bad. The axleshaft carries the load and transfers the power. Bad. There's a roller bearing that rides on the outside edge of the axleshaft and that's your load carrier. Bad. This is bad rear for a pickup that's going to get used. Not as much bearing as a full floater and if you break an axleshaft, you lose the wheel. Also, when the axleshaft wears from the bearing riding on it, the axleshaft is junk. These rearends also had a smaller ring gear than a full floater. Most RWD cars, 1/2 ton pickups and some later 3/4 ton pickups have this. The year you're looking at may not have had this available, but be aware of it. Look for that protrusion through the wheel.

If you can find a 3/4 ton with a 350, Turbo 350 and a NP205 you've got it made. A 205 is going to have a cast iron case. Pics:

The stick

 

[chowdozer]

you are quick on the replies thanks,

I'm not quite following you on the full floater compared to the ten bolt can you explain.

I will find out more about the half ton most importantly the price and having it up on a lift later but I'm thinking I may just put less weight in the truck and tow it with a trailer instead.

the half ton is in a lot better condition but I'm not too keen on the th350 tranny.
especially since it is on it's second rebuild, the shop screwed up the first one and the tranny lost third gear so they are doing the second rebuild on warranty.

I was hoping for an sm465

I think I just need a little more patience but I'm really itching for a truck

Given the choice between a Turbo 350 and a SM465, I'll take the 465. Which is why I have one.

The Turbo 350 can be built up very good, but it sounds like the tranny shop doing the work is lacking. In that case, I'd definitely be looking for the 465.

 

[JONSSTIHL]

thanks for the lesson

yep that 79 was a full floater rear axle it is too bad the rest of the truck was so beat up because it was the perfect mechanical combination.

this 1/2 ton is part time with manual locking hubs so probably a np 205

maybe i'll just throw 1/2 a face cord in the bed and tow the rest in a trailer.

but I still really want a 3/4 ton.

but now I'm thinking the 1/2 ton will get much better mileage around town than the 3/4 ton with 4.56 gears.

how much do you figure it would cost to rebuild the 10 bolt on the 79 3/4 ton. for moog parts I<m looking at 240 just for ball joints

 

[chowdozer]

thanks for the lesson

yep that 79 was a full floater rear axle it is too bad the rest of the truck was so beat up because it was the perfect mechanical combination.

this 1/2 ton is part time with manual locking hubs so probably a np 205

maybe i'll just throw 1/2 a face cord in the bed and tow the rest in a trailer.

but I still really want a 3/4 ton.

but now I'm thinking the 1/2 ton will get much better mileage around town than the 3/4 ton with 4.56 gears.

how much do you figure it would cost to rebuild the 10 bolt on the 79 3/4 ton. for moog parts I<m looking at 240 just for ball joints

I don't know how much it's going to cost to rebuild a frontend.

I'll give you something to think about though.

If you buy a half ton, you will overload it. It's just a matter of time and the thought of "just a few more pieces".

Be patient, you'll find a 3/4 ton.

 

[GASoline71]

how much do you figure it would cost to rebuild the 10 bolt on the 79 3/4 ton. for moog parts I<m looking at 240 just for ball joints

You're gettin' ripped off... Those ball joints shouldn't be more than 20-30 bucks apiece. Go to Napa and just buy their brand. Forget Moog... you're payin' for a name on the box.

Great post on the axle and tranny chowdozy!

Gary

 

[GASoline71]

I don't know how much it's going to cost to rebuild a frontend.

I'll give you something to think about though.

If you buy a half ton, you will overload it. It's just a matter of time and the thought of "just a few more pieces".

Be patient, you'll find a 3/4 ton.

Agreed... even if you partially load that half ton and then try to pull a loaded trailer... your gonna lug that truck down more that it should handle.

If you're lookin' at these old Chevy's and GMC's... 1/2 ton or 3/4 ton... gas mileage is gonna be the same with a small block 350. Doesn't matter what tranny/transfer case combo you got... gas mileage is gonna suck period.

Gary

 

[JONSSTIHL]

thanks a lot for the therapy guys,

i do need a 3/4 ton or maybe a 1 ton.

the half ton sounds like an accident waiting to happen. I just have to work on my patience.

 

[JONSSTIHL]

found one!!

well I finally found one
and I decided to go bigger rather than smaller. and I figured fuel injection was the way to go

it is a 1991 1 ton 4x4 crew cab with an automatic and a tbi 350

i paid a little more than I wanted to put into a truck but 3200$ isn't too bad

it has a dana 60 front axle and a gm 14 bolt full floater on the rear

I will get pics tonight I'm at work now

 

[JONSSTIHL]

here is a pic

 

[pbtree]

Looks nice dude!

 

[chowdozer]

here is a pic

Good looking truck and a fair price too. You love that truck and you'll love how easy it is to work on.

 

[JONSSTIHL]

i got it home about 50 mile trip and it sounded like it was running on two cylinders at idle. turns out the egr valve had broken off its base and was bypassing exhaust gas all the time.

the only problem is that it is so high it is a pain to work under the hood. I need a step ladder just to reach the throttle body, but the good thing is I don't need to jack it to change the oil

fair price is what I was thinking too, I didn't steal it but I didn't get taken for a ride either

I like it so far, too bad the intake manifold started leaking coolant at the front drivers side. I think that is one thing I will take it to a mechanic for. I changed the egr valve without too much trouble but removing the whole intake is a whole other ball game.

 

[JONSSTIHL]

anyone have any idea what transfer case is in it. It is part time 4wd with manual locking hubs.

from what the previous owner said I think it has a 4l80e transmission in it. it has overdrive.

and I really like all the room under the hood spark plug change took me 15 minutes

 

[clearance]

anyone have any idea what transfer case is in it. It is part time 4wd with manual locking hubs.

from what the previous owner said I think it has a 4l80e transmission in it. it has overdrive.

and I really like all the room under the hood spark plug change took me 15 minutes

I think it is a New Process 205, it takes gear oil, same as the differentials, 80W90. Best to find out for sure though.

 

[Austin1]

I think it is a New Process 205, it takes gear oil, same as the differentials, 80W90. Best to find out for sure though.

Is that what it had in it or what the manual say's? People always seem to put gear oil in a 203!You have seen many picks now so you know what your looking at so I am not doubting you. It is just that I have seen so many np203 with gear oil in them over the years.

 

[clearance]

Is that what it had in it or what the manual say's? People always seem to put gear oil in a 203!You have seen many picks now so you know what your looking at so I am not doubting you. It is just that I have seen so many np203 with gear oil in them over the years.

205, not 203, totally diferent animal.

 

[chowdozer]

anyone have any idea what transfer case is in it. It is part time 4wd with manual locking hubs.

from what the previous owner said I think it has a 4l80e transmission in it. it has overdrive.

and I really like all the room under the hood spark plug change took me 15 minutes

Jon, you either have a part time NP205 gear driven cast iron case

or

you have a part time chain driven NP208 with a aluminum case.

Just poke your head under there and look for iron or aluminum.

 

[chowdozer]

i got it home about 50 mile trip and it sounded like it was running on two cylinders at idle. turns out the egr valve had broken off its base and was bypassing exhaust gas all the time.

the only problem is that it is so high it is a pain to work under the hood. I need a step ladder just to reach the throttle body, but the good thing is I don't need to jack it to change the oil

fair price is what I was thinking too, I didn't steal it but I didn't get taken for a ride either

I like it so far, too bad the intake manifold started leaking coolant at the front drivers side. I think that is one thing I will take it to a mechanic for. I changed the egr valve without too much trouble but removing the whole intake is a whole other ball game.

Intake, easy as pie. Saturday afternoon while taking the time to drink a 6 pack.

Let me know if you're going to do it.