1 piece or 2 piece drive shaft advise - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70GMCer · 10-29-2006, 08:10 AM

I'm getting at the point where I'm going to be shortening the drive shaft in my 70 1/2T long fleet. It has a 350 turbo in at the moment. I'm installing a 700r4 and will be taking 3 inches off the shaft. Question is, since I'm going through all this, should I just convert to a 1 piece shaft or stay with the 2 piece one? The truck is stock height, and will be staying that way. Are there any major mods to do too the frame for a 1 piece? Will the carrier support be in the way of a 1 piece? Any advice??

steve

Longhorn Man · 10-29-2006, 10:34 AM

there is no good reason IMO to swap to a one piece in a LWB truck. Get good componentes, have a drive shaft shop assemble and ballance it, and you sholuld be good for another 10 - 15 years on U-joints, and 30 years on the C-bearing... and that's if it's a daily driver.

Brad · 10-29-2006, 01:10 PM

Andy and I always disagree on this everytime it comes up, but here's what it boils down to: If you ever have to replace the carrier bearing with one of those cheap aftermarket flimsy ones- you'll regret that you ever stayed with the 2-piece driveshaft! The problem is that most of the time they don't last more than a year- maybe less, and you'll be right back to square one and having to do it all over again. Whereas the 1-piece dl's you can get rid of alot of that crap and be done with it forever. Many have done a 1-piece on a LWB and have done just fine with no problems whatsoever.

If you decide to keep the 2-piece, (which in it's stock form was great) do yourself a favor and either A)weld up the craptabulous cheapy bearing around the lip so that the rubber inside doesn't spin (this is why they don't last) or B)spend the extra $$$ and get one of those billet/polyurethane aftermarket bearings. They're expensive, but I've heard they're good.

**jerry moss** · 10-29-2006, 05:04 PM

one piece or two piece depends on the length of the shaft according to my local driveline shop. if i remember correctly 60" is the maximum length on a one piece shaft.

**truckdude239** · 10-29-2006, 06:45 PM

i pulled my c-bearing off my truck after 34 years and am regetting it since it was till strong and got to thinking hey while i'm here well 6 months later it broke (the one i got from orielys) i got a new one from advance auto i could tell right off it was a better one its in there and still strong no troubles since i installed it

1978steven · 10-29-2006, 07:27 PM

I don't want to take over GMCer's thread.... But.....

What modifications would have to be done to run a 1 piece drive shaft? Would you be able to lower the truck any with a 1 piece drive shaft? Both question are for the long wheel base trucks....

Steven

kbs71 · 10-30-2006, 09:19 AM

Check out this thread. I should help you out. http://67-72chevytrucks.com/vboard/s...d.php?t=131693

**1970 CST Short Wide** · 10-30-2006, 09:57 AM

I agree with Brad. If you stay with the 2 piece get GOOD parts.
I personally have a 1 piece in my SWB and have NO problems what so ever. My son had a 1 piece in his LWB and it too worked fine but we always thought we felt a slight vibration even after having the shop re check the balance.

Your right Jerry 60 inches is what Driveline specialty recommends as far as Max length and then you have to go with bigger tubing

b&a72 · 10-30-2006, 10:26 AM

If you have a high torque or horsepower engine go with a one piece. It took me breaking 3 carrier bearings to realize it, my 1 piece is awesome.

1978steven · 10-30-2006, 01:51 PM

Quote:

Originally Posted by kbs71

Check out this thread. I should help you out. http://67-72chevytrucks.com/vboard/s...d.php?t=131693

Link isn't working for me??????

Longhorn Man · 10-30-2006, 03:55 PM

Quote:

Originally Posted by b&a72

If you have a high torque or horsepower engine go with a one piece. It took me breaking 3 carrier bearings to realize it, my 1 piece is awesome.

On a LWB, high power and torque is all the more reason to stay with 2 pce.
If your carrier bearing is snapping, you either need to get better parts, or find the real problem. I've seen a 1/2 ton 68 LWB doing 12's in the 1/4, good traction, (only spin the tires 5 or 6 feet outta the hole) stock 2 pce drive shafts, and the carrier bearing was the original 250,000 mile piece.

70GMCer · 10-30-2006, 04:35 PM

A lot of good advice here. I have a 84 Suburban 1 piece shaft, that was what I was thinking on using. Still not decided yet. I have a moderately built 350 and have never had problems with my 2 piece. Was just wondering about if I have to shorten one, why not the 1 piece one I have? Either way, it's going to cost the same.

b&a72 · 10-30-2006, 04:35 PM

That may be the case but since I went to a 1 piece I have not had one problem. I prefer the 1 piece anyways I guess it is a preference, but that is some good info thanks Longhorn!

Longhorn Man · 10-30-2006, 08:31 PM

I realize I didn't elaborate.
The tranny and engine are secured to the frame and cross member. There should be no left and right movement at all. It'll twist a little, but nothing else. So twisting the drive shaft in direct line is all that is supposed to be going on with the front shaft.
If your engine and tranny are bolted in at the wrong angle (laft and right... not centered) then you could be snapping C-bearings. If you have the wrong angle as far as nose height and tailshaft height, that could break the C-bearing. A combo of both problems would play hell ...throw in a broken drivers side motor mount, and the bearing is bound to break. A one piece shaft will not be effected by these problems. It only has to go from point a to point b... there is nothing holding it in the center.
Now, a one piece shaft should not be made longer than 6 ft. (talking steel, not the modern fragile alluminum ones) The reason 6 ft is the industry standard, is becouse the shaft starts to sag if it is longer. You may not be able to see it, but you'll feel it 'whipping' as you go faster.
Now, some places CAN actually make a shaft longer than 6 ft, however, they have to make it out of rather large tubing. There is normally fitment issues going through the cross member.
The 2 piece is stronger, becouse a short pipe will always be stronger than a long one, if all variables are the same between the 2. It's easier to twist a long one into a twizler. No, not common at all, and yes it takes some seriouse power and traction... I'm only mentioning it becouse so many ppl think a one piece is stronger.
There are plenty of people who have had one piece shafts made, and work good. There's plenty of shops that'll make one for you... most of them shouldn't... but there are some places that can do it, and do it right.
If you were to measure the one under the suburban, You'll probably find it to be too short. They moved the engine further back in 73, and later went to long shaft trannys to get it all back far enough to use one piece shafts.

myfirstcarwasa73trk · 10-30-2006, 09:30 PM

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heres mine

67 LSS
85 gmc LWB

10-29-2006, 08:10 AM	#1
70GMCer Senior Member Join Date: Apr 2005 Location: Joppa, Maryland Posts: 4,408	1 piece or 2 piece drive shaft advise I'm getting at the point where I'm going to be shortening the drive shaft in my 70 1/2T long fleet. It has a 350 turbo in at the moment. I'm installing a 700r4 and will be taking 3 inches off the shaft. Question is, since I'm going through all this, should I just convert to a 1 piece shaft or stay with the 2 piece one? The truck is stock height, and will be staying that way. Are there any major mods to do too the frame for a 1 piece? Will the carrier support be in the way of a 1 piece? Any advice?? steve __________________ 1997 GMC Sierra Ext 1965 Mustang Last edited by 70GMCer; 10-29-2006 at 08:12 AM.

10-29-2006, 10:34 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 1 piece or 2 piece drive shaft advise there is no good reason IMO to swap to a one piece in a LWB truck. Get good componentes, have a drive shaft shop assemble and ballance it, and you sholuld be good for another 10 - 15 years on U-joints, and 30 years on the C-bearing... and that's if it's a daily driver.

10-29-2006, 01:10 PM	#3
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Re: 1 piece or 2 piece drive shaft advise Andy and I always disagree on this everytime it comes up, but here's what it boils down to: If you ever have to replace the carrier bearing with one of those cheap aftermarket flimsy ones- you'll regret that you ever stayed with the 2-piece driveshaft! The problem is that most of the time they don't last more than a year- maybe less, and you'll be right back to square one and having to do it all over again. Whereas the 1-piece dl's you can get rid of alot of that crap and be done with it forever. Many have done a 1-piece on a LWB and have done just fine with no problems whatsoever. If you decide to keep the 2-piece, (which in it's stock form was great) do yourself a favor and either A)weld up the craptabulous cheapy bearing around the lip so that the rubber inside doesn't spin (this is why they don't last) or B)spend the extra $$$ and get one of those billet/polyurethane aftermarket bearings. They're expensive, but I've heard they're good. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

10-29-2006, 05:04 PM	#4
jerry moss Born Psycho Join Date: Feb 2001 Location: brentwood,cal,usa Posts: 4,768	Re: 1 piece or 2 piece drive shaft advise one piece or two piece depends on the length of the shaft according to my local driveline shop. if i remember correctly 60" is the maximum length on a one piece shaft. __________________ jerry moss 72 cheyenne super K20- tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,tow hooks,bumper guards,toolbox,aux. fuel tank,posi front and rear,plus other goodies!!! SOLD 69 suburban K20-tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,4 inch all spring lift,4 speed, 14 bolt full floater, dana 44 HD,warn winch,posi front and rear,tow hooks,plus other goodies. 73/80 chevy/gmc K20 SB400,turbo 400,205,tilt,a-c,gas hog. 77 K/5 cheyenne blazer-daily driver/beater. SON HAS IT NOW BRENTWOOD,CALIFORNIA

10-29-2006, 06:45 PM	#5
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,217	Re: 1 piece or 2 piece drive shaft advise i pulled my c-bearing off my truck after 34 years and am regetting it since it was till strong and got to thinking hey while i'm here well 6 months later it broke (the one i got from orielys) i got a new one from advance auto i could tell right off it was a better one its in there and still strong no troubles since i installed it __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-29-2006, 07:27 PM	#6
1978steven Registered User Join Date: Oct 2004 Location: Currently New Windsor, NY but Texas is home Posts: 332	Re: 1 piece or 2 piece drive shaft advise I don't want to take over GMCer's thread.... But..... What modifications would have to be done to run a 1 piece drive shaft? Would you be able to lower the truck any with a 1 piece drive shaft? Both question are for the long wheel base trucks.... Steven __________________ 2002 Silverado 2500HD LB7 CCSB LT EFI Live by Rob at ATP, Edge CTS Insight DSP 5 control, S&B CAI, PPE boost valve, Pro Fab AIH, AirDog II 165, PPE WIF sensor delete plug, 5" stainless exhaust, Cognito braces & HD tie rods, H2's 315/70 R17 BFG's 2004 Tahoe LT 2006 Silverado Z71 LS 1971 Chevy C10 Last edited by 1978steven; 10-29-2006 at 07:29 PM.

10-30-2006, 09:19 AM	#7
kbs71 71 rustless in texas Join Date: Aug 2004 Location: Houston, TX Posts: 257	Re: 1 piece or 2 piece drive shaft advise Check out this thread. I should help you out. http://67-72chevytrucks.com/vboard/s...d.php?t=131693 __________________ "The secret to creativity is knowing how to hide your sources." "No one really listens to anyone else, and if you try it for a while you'll see why" 71 C-10 LWB presently in a perpetual state of disassembly '96 Toyota (my work car) '04 Mustang Convertable (wife's car & other money pit) Latest aquesition and why my trucks still in the garage covered with junk.. 2010 Aqua Blue metallic 6 speed Manual LS3 2SS/RS Camaro (I want one of these in my truck FAQ here VENDORS here SUPPORT THE BOARD here My second favorite SITE Last edited by kbs71; 10-30-2006 at 09:20 AM.

10-30-2006, 09:57 AM	#8
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,074	Re: 1 piece or 2 piece drive shaft advise I agree with Brad. If you stay with the 2 piece get GOOD parts. I personally have a 1 piece in my SWB and have NO problems what so ever. My son had a 1 piece in his LWB and it too worked fine but we always thought we felt a slight vibration even after having the shop re check the balance. Your right Jerry 60 inches is what Driveline specialty recommends as far as Max length and then you have to go with bigger tubing __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2019 GMC Diesil Dually. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

10-30-2006, 10:26 AM	#9
b&a72 Active Member Join Date: Oct 2006 Location: Mesa, AZ Posts: 682	Re: 1 piece or 2 piece drive shaft advise If you have a high torque or horsepower engine go with a one piece. It took me breaking 3 carrier bearings to realize it, my 1 piece is awesome.

10-30-2006, 04:35 PM	#12
70GMCer Senior Member Join Date: Apr 2005 Location: Joppa, Maryland Posts: 4,408	Re: 1 piece or 2 piece drive shaft advise A lot of good advice here. I have a 84 Suburban 1 piece shaft, that was what I was thinking on using. Still not decided yet. I have a moderately built 350 and have never had problems with my 2 piece. Was just wondering about if I have to shorten one, why not the 1 piece one I have? Either way, it's going to cost the same. __________________ 1997 GMC Sierra Ext 1965 Mustang

10-30-2006, 08:31 PM	#14
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 1 piece or 2 piece drive shaft advise I realize I didn't elaborate. The tranny and engine are secured to the frame and cross member. There should be no left and right movement at all. It'll twist a little, but nothing else. So twisting the drive shaft in direct line is all that is supposed to be going on with the front shaft. If your engine and tranny are bolted in at the wrong angle (laft and right... not centered) then you could be snapping C-bearings. If you have the wrong angle as far as nose height and tailshaft height, that could break the C-bearing. A combo of both problems would play hell ...throw in a broken drivers side motor mount, and the bearing is bound to break. A one piece shaft will not be effected by these problems. It only has to go from point a to point b... there is nothing holding it in the center. Now, a one piece shaft should not be made longer than 6 ft. (talking steel, not the modern fragile alluminum ones) The reason 6 ft is the industry standard, is becouse the shaft starts to sag if it is longer. You may not be able to see it, but you'll feel it 'whipping' as you go faster. Now, some places CAN actually make a shaft longer than 6 ft, however, they have to make it out of rather large tubing. There is normally fitment issues going through the cross member. The 2 piece is stronger, becouse a short pipe will always be stronger than a long one, if all variables are the same between the 2. It's easier to twist a long one into a twizler. No, not common at all, and yes it takes some seriouse power and traction... I'm only mentioning it becouse so many ppl think a one piece is stronger. There are plenty of people who have had one piece shafts made, and work good. There's plenty of shops that'll make one for you... most of them shouldn't... but there are some places that can do it, and do it right. If you were to measure the one under the suburban, You'll probably find it to be too short. They moved the engine further back in 73, and later went to long shaft trannys to get it all back far enough to use one piece shafts.

10-30-2006, 09:30 PM	#15
myfirstcarwasa73trk Registered User Join Date: Oct 2006 Location: TEXAS scurry Posts: 183	Re: 1 piece or 2 piece drive shaft advise heres mine 67 LSS 85 gmc LWB



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