1 piece driveshaft in LWB - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ratrod67 · 12-02-2005, 10:31 AM

I need to get a driveshaft done for my 72 LWB Chevy. I'm running a 509 ci BBC and a T350 transmission. They guy that builds my driveshafts for me is telling me to get a 1 piece driveshaft. He says I will break the 2 piece shafts with my motor. I did the search here for info on the 1 piece in a LWB but it says driveshaft is not a valid search word. Should I get the 1 piece or not?

bigjimzlll · 12-02-2005, 10:49 AM

I went to a one piece with my LWB. I could not get a driveline shop to make one that was the needed almost 6 feet long. I moved the engine back 4 inches and used a th400 Long tail shaft tranny. This allowed me to use a 3.5" DOM shaft thats 59" long. Ofcourse I spin a lot of rpms...this is a determining factor on driveshaft length

67k-20 · 12-02-2005, 12:25 PM

my 68 lwb had a factory 1-piece driveshaft. just incase you wanted to save some money.

Maximum Overdrive · 12-02-2005, 12:52 PM

What determines a one piece or two piece driveshaft is critical speed. Critical speed is the number of RPM's at which the shaft will explode.
Critical speed is related to weight, length, diameter, and the speed of the shaft. Longer shafts tend to be heavier and can come apart at highway speeds.

As far as I know most LWB trucks came with a two piece though some were known to have a once piece shaft but they tended to come with I-6.

70rs/ss · 12-02-2005, 01:19 PM

Quote:

Originally Posted by Maximum Overdrive

What determines a one piece or two piece driveshaft is critical speed. Critical speed is the number of RPM's at which the shaft will explode.
Critical speed is related to weight, length, diameter, and the speed of the shaft. Longer shafts tend to be heavier and can come apart at highway speeds.

As far as I know most LWB trucks came with a two piece though some were known to have a once piece shaft but they tended to come with I-6.

In today's trucks they come with a one piece aluminum wrapped drivshaft yada yadda, but the technology can be implimented into our older trucks. I did a search for another member about an aluminum shaft and I can tell you if your shop can't or won't build one find another shop. If you have that kinda cash in a 509 don't think some 30-40 year old shaft will work, spend the $500-600 that it takes to have a custon shaft built for you and then you will not have to move the motor, nor will you have to be worried about driveshaft failure.

76bonanza · 12-02-2005, 01:30 PM

I have a custom made one piece in my truck only problem we had was with it lowered we had to modify the cross piece it goes thru in the rear. Dont have a price friend did it for me. I do have a th400 tho.

davidh · 12-02-2005, 02:48 PM

I think if the tranny was a long tail turbo 350 it wouldn't be a big deal.

red71cheyenne · 12-02-2005, 04:56 PM

I run a one piece in the 71 and only have issues of it hitting the crossmember on big bumps. Other than that its fine. Jeff. By the way, its 67.5 inches long.

ratrod67 · 12-02-2005, 06:01 PM

Thanks for all the help. I'm not concerned with the cost. I get driveshafts made for $125 if I furnish the yoke. $150 if I don't. I was mainly concerned with tales of not being able to balance them right and whipping at high RPM. My truck is pretty low and I was also concerned about the shaft hitting the crossmember as said above. When I switched to BBC mounts from the SBC mounts it moved the motor and transmission back a couple inches. I had to drill holes to mount the transmission crossmember to the frame. It looks like it also made my stock driveshaft too long. The guy who does the shafts said he does 1 piece for the LWB trucks all the time but none for super high performance trucks. I just want it done right the first time.

71Dragtruck · 12-02-2005, 09:57 PM

Quote:

Originally Posted by ratrod67

I need to get a driveshaft done for my 72 LWB Chevy. I'm running a 509 ci BBC and a T350 transmission. They guy that builds my driveshafts for me is telling me to get a 1 piece driveshaft. He says I will break the 2 piece shafts with my motor. I did the search here for info on the 1 piece in a LWB but it says driveshaft is not a valid search word. Should I get the 1 piece or not?

What is behind his thinking that you will break 2-piece shafts? I have a 2-piece 3" chrome alloy shaft running a custom steady, a splined back piece and 1350 u-joints. I was told the that I would break 1 piece shafts. I've had no problems so far, I'll see how it does behind my new mill this summer.

bigjimzlll · 12-02-2005, 10:00 PM

My local track really frowned on the 2 piece deal. I could'nt find in the NHRA rule book where it violated any rule though.

ratrod67 · 12-02-2005, 10:01 PM

Quote:

Originally Posted by 71Dragtruck

What is behind his thinking that you will break 2-piece shafts? I have a 2-piece 3" chrome alloy shaft running a custom steady, a splined back piece and 1350 u-joints. I was told the that I would break 1 piece shafts. I've had no problems so far, I'll see how it does behind my new mill this summer.

Not sure why he reccomended the 1 piece shaft. It's what he does for a living though. He's always done good work for me and is highly reccomended around here. He did the 1 piece shaft in my 67 SWB, Camaros and Chevelle. I just figured I needed the 2 piece shaft since it's a LWB truck. It surprised me when he said a 1 piece.

corn · 12-02-2005, 10:28 PM

A friend of mine told me that his dad put a suburban driveshaft in his 71. One piece & it bolted right in (he says). Was he blowing smoke up my tailpipe or can it be that simple?

71Dragtruck · 12-02-2005, 10:29 PM

I'm just kind of wondering, I went through the same thing, I wanted a 1-piece. I had mine done when I got it 4-linked, the place that did it said they built a 1-piece for a guy with a 84 Chev drag truck and he broke 2, so they built him one like they made me and it worked fine?

71Dragtruck · 12-02-2005, 10:31 PM

Quote:

Originally Posted by bigjimzlll

My local track really frowned on the 2 piece deal. I could'nt find in the NHRA rule book where it violated any rule though.

Did they give you a reason? My track never said a thing about mine, I have 2 loops if that makes a differance.

kbs71 · 12-03-2005, 12:51 AM

Check out this thread. I updated it about a year ago and haven't had any trouble with my 1 piece yet. One of the best $120.00 upgrades I've done.
http://67-72chevytrucks.com/vboard/s...d.php?t=131693

ZOOMY · 12-03-2005, 08:17 AM

For what it's worth, I have a '67 LWB GMC parts truck here with a factory 1 piece driveshaft, so the factory did it on some trucks..

ratrod67 · 12-06-2005, 10:28 PM

Well, I got talked into the 1 piece driveshaft. Hopefully I'll get it in the truck and go for a spin this weekend.

Longhorn Man · 12-06-2005, 11:26 PM

A 2 piece would be stronger.
A center U joint is no weaker than the other 2 U joints, and the carrier bearing shouldn't be an issue either.

jhow66 · 12-06-2005, 11:59 PM

Got a 502HO in my Cheyenne SWB with a T400 and 2 piece-no problems.

Longhorn Man · 12-07-2005, 06:26 AM

if they were so weak, they wouldn't be under trucks. period. I've seen street trucks doin 12's that has stock 2 pc driveshafts,
bug trucks with mega torque...... 3pce...4pce... even more on straight trucks.... never a problem.

GloryHound · 12-07-2005, 03:09 PM

Quote:

Originally Posted by 71Dragtruck

Did they give you a reason? My track never said a thing about mine, I have 2 loops if that makes a differance.

2-loops make all the difference in the world to those guys. I've been hangin with a drag racing crowd and the track most of them go to and the class they are racing in says each drive shaft is required to have a loop. Also scatter shields are mandatory on stick shifts and highly recommended on automatics. Also the track has required most of them to install 8 pt. roll cages do to their speed.

Now these guys are driving Nova's and getting to right around 10 second times. Alot better than I ever intend to go since my car will be more street then strip, but safety features are always good things when you plan on going fast!

12-02-2005, 10:31 AM	#1
ratrod67 Registered User Join Date: Sep 2002 Location: DFW Texas Posts: 2,269	1 piece driveshaft in LWB I need to get a driveshaft done for my 72 LWB Chevy. I'm running a 509 ci BBC and a T350 transmission. They guy that builds my driveshafts for me is telling me to get a 1 piece driveshaft. He says I will break the 2 piece shafts with my motor. I did the search here for info on the 1 piece in a LWB but it says driveshaft is not a valid search word. Should I get the 1 piece or not?

12-02-2005, 10:49 AM	#2
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	Re: 1 piece driveshaft in LWB I went to a one piece with my LWB. I could not get a driveline shop to make one that was the needed almost 6 feet long. I moved the engine back 4 inches and used a th400 Long tail shaft tranny. This allowed me to use a 3.5" DOM shaft thats 59" long. Ofcourse I spin a lot of rpms...this is a determining factor on driveshaft length __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

12-02-2005, 12:25 PM	#3
67k-20 Registered User Join Date: May 2005 Posts: 15	Re: 1 piece driveshaft in LWB my 68 lwb had a factory 1-piece driveshaft. just incase you wanted to save some money.

12-02-2005, 12:52 PM	#4
Maximum Overdrive December 21, 2012 Join Date: Apr 2000 Location: Black Eagle, Montana Posts: 1,633	Re: 1 piece driveshaft in LWB What determines a one piece or two piece driveshaft is critical speed. Critical speed is the number of RPM's at which the shaft will explode. Critical speed is related to weight, length, diameter, and the speed of the shaft. Longer shafts tend to be heavier and can come apart at highway speeds. As far as I know most LWB trucks came with a two piece though some were known to have a once piece shaft but they tended to come with I-6. __________________ *"!Ama Sua, Ama Kjella, Ama Lllulla!"* Last edited by Maximum Overdrive; 12-02-2005 at 12:54 PM.

12-02-2005, 01:30 PM	#6
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Re: 1 piece driveshaft in LWB I have a custom made one piece in my truck only problem we had was with it lowered we had to modify the cross piece it goes thru in the rear. Dont have a price friend did it for me. I do have a th400 tho. __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

12-02-2005, 02:48 PM	#7
davidh Senior Member Join Date: Feb 2004 Location: Ponca city now kingfisher Oklahoma Posts: 1,220	Re: 1 piece driveshaft in LWB I think if the tranny was a long tail turbo 350 it wouldn't be a big deal.

12-02-2005, 04:56 PM	#8
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Re: 1 piece driveshaft in LWB I run a one piece in the 71 and only have issues of it hitting the crossmember on big bumps. Other than that its fine. Jeff. By the way, its 67.5 inches long. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

12-02-2005, 06:01 PM	#9
ratrod67 Registered User Join Date: Sep 2002 Location: DFW Texas Posts: 2,269	Re: 1 piece driveshaft in LWB Thanks for all the help. I'm not concerned with the cost. I get driveshafts made for $125 if I furnish the yoke. $150 if I don't. I was mainly concerned with tales of not being able to balance them right and whipping at high RPM. My truck is pretty low and I was also concerned about the shaft hitting the crossmember as said above. When I switched to BBC mounts from the SBC mounts it moved the motor and transmission back a couple inches. I had to drill holes to mount the transmission crossmember to the frame. It looks like it also made my stock driveshaft too long. The guy who does the shafts said he does 1 piece for the LWB trucks all the time but none for super high performance trucks. I just want it done right the first time.

12-02-2005, 10:00 PM	#11
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	Re: 1 piece driveshaft in LWB My local track really frowned on the 2 piece deal. I could'nt find in the NHRA rule book where it violated any rule though. __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

12-02-2005, 10:28 PM	#13
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	Re: 1 piece driveshaft in LWB A friend of mine told me that his dad put a suburban driveshaft in his 71. One piece & it bolted right in (he says). Was he blowing smoke up my tailpipe or can it be that simple?

12-02-2005, 10:29 PM	#14
71Dragtruck Registered User Join Date: Jun 2004 Location: Saskatchewan, Canada Posts: 1,368	Re: 1 piece driveshaft in LWB I'm just kind of wondering, I went through the same thing, I wanted a 1-piece. I had mine done when I got it 4-linked, the place that did it said they built a 1-piece for a guy with a 84 Chev drag truck and he broke 2, so they built him one like they made me and it worked fine? __________________ Speed is just a matter of money, question is how fast can you afford to go? 8.95@148.97mph all motor haven't tried bottle yet Sponsored by: Getz Oilfield Consulting Hard Candy Customs Last edited by 71Dragtruck; 12-02-2005 at 10:32 PM.

12-03-2005, 12:51 AM	#16
kbs71 71 rustless in texas Join Date: Aug 2004 Location: Houston, TX Posts: 257	Re: 1 piece driveshaft in LWB Check out this thread. I updated it about a year ago and haven't had any trouble with my 1 piece yet. One of the best $120.00 upgrades I've done. 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

12-03-2005, 08:17 AM	#17
ZOOMY Senior Member Join Date: Feb 2003 Location: WIS Posts: 1,752	Re: 1 piece driveshaft in LWB For what it's worth, I have a '67 LWB GMC parts truck here with a factory 1 piece driveshaft, so the factory did it on some trucks..

12-06-2005, 10:28 PM	#18
ratrod67 Registered User Join Date: Sep 2002 Location: DFW Texas Posts: 2,269	Re: 1 piece driveshaft in LWB Well, I got talked into the 1 piece driveshaft. Hopefully I'll get it in the truck and go for a spin this weekend.

12-06-2005, 11:26 PM	#19
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: 1 piece driveshaft in LWB A 2 piece would be stronger. A center U joint is no weaker than the other 2 U joints, and the carrier bearing shouldn't be an issue either.



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12-06-2005, 11:59 PM	#20
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Re: 1 piece driveshaft in LWB Got a 502HO in my Cheyenne SWB with a T400 and 2 piece-no problems. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

12-07-2005, 06:26 AM	#21
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: 1 piece driveshaft in LWB if they were so weak, they wouldn't be under trucks. period. I've seen street trucks doin 12's that has stock 2 pc driveshafts, bug trucks with mega torque...... 3pce...4pce... even more on straight trucks.... never a problem.

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