Need help with getting one piece drive shaft in LWB - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sam's 72 · 09-05-2002, 09:29 AM

I have my truck over at a friend of mine tranny shop, we are putting in a built up 700r4 in it. I want to go with a one piece drive shaft, he calls me today and tells me that he dont think it is a good ideal to cut out the loop that the drive shaft is going through to get the one piece drive shaft in. The rear trailing arms are conected to this. what I want to know is who has done this conversion? And is there any trouble with cutting out the loop to get the single piece shaft in the truck? I know a lot of you guys have done this, what did you do? did you box it back in, or just left it cut out?
Sam

slam33 · 09-05-2002, 10:03 AM

You will weaken that crossmember, and that long of a drive shaft will give you problems becuse of the length. It will start to whip in the center. You going to need at least a 4 inch shaft and keep your fingers crossed

**1970 CST Short Wide** · 09-05-2002, 10:24 AM

On my Short Bed I used a 1 piece shaft and cut out the hagger for the carrier, BUT on a long bed I think a 1 piece would be too long and you might get wobble at higher speeds.

Think It out

sam's 72 · 09-05-2002, 01:10 PM

TTT

HvyChevy454 · 09-05-2002, 04:24 PM

i saw a lWB at a show that a a 1piece behind a blown 468BB. all he had to do was notch the center loop abount an inch, but he also had what looked to be a 4/6 drop though

90\87Formula · 09-05-2002, 07:52 PM

Most driveline shops will tell you a one piece driveshaft shouldn't be longer than 6 foot. Longer onepieces will create vibration and eventually failure.
It's not necessarilly the diameter, but the wall thickness of the tube.
I went from Powerglide to TH400. I didn't cut out the loop ,but I did have to cut out the piece that held the carrier bearing to the loop.
I wouldn't cut out the loop, these frames flex enough as it is.
Just my .02 cents worth.
Good luck, whatever you do.

72chevyLWB · 09-05-2002, 08:00 PM

I have a 700R4 in my truck and HAD a 1pc driveshaft. It does whip in the center which gives you a nasty vibration and eventually loosens your pinion nut. Then the nut comes off and the pinion runs into your carrier and makes a really interesting noise. Oh yeah and then it ruins your rear tranny seal also. DO NOT EVER USE A 1 PIECE DRIVESHAFT ON A LWB TRUCK. You will me much happier with a 2 piece.

Brad · 09-05-2002, 08:55 PM

See my replies on this thread:
http://67-72chevytrucks.com/vboard/s...threadid=21656

**Tim Christian** · 09-05-2002, 10:40 PM

Guys,Guys,Guys About all GMC long wheelbase trucks I have ever seen came factory with a one piece drive shaft. I have owned two of them myself and the drive shaft ran right through the center of the loop from the factory. No whiping, No vibration or nothing. Matter of fact I still have one of the frames laying here in the yard if you would like to see pictures. I also still have one of the factory long one piece drive shafts.

09-05-2002, 09:29 AM	#1
sam's 72 Senior Member Join Date: Nov 2001 Location: Pasadena, Texas, USA Posts: 1,005	Need help with getting one piece drive shaft in LWB I have my truck over at a friend of mine tranny shop, we are putting in a built up 700r4 in it. I want to go with a one piece drive shaft, he calls me today and tells me that he dont think it is a good ideal to cut out the loop that the drive shaft is going through to get the one piece drive shaft in. The rear trailing arms are conected to this. what I want to know is who has done this conversion? And is there any trouble with cutting out the loop to get the single piece shaft in the truck? I know a lot of you guys have done this, what did you do? did you box it back in, or just left it cut out? Sam __________________ 72 LWB chevy truck. Pasadena, Texas

09-05-2002, 10:03 AM	#2
slam33 Registered User Join Date: Aug 2001 Location: Long Beach, Ca Posts: 1,432	You will weaken that crossmember, and that long of a drive shaft will give you problems becuse of the length. It will start to whip in the center. You going to need at least a 4 inch shaft and keep your fingers crossed __________________ 71 LWB 350/350still working on it but it's going tp be sweet. www.geocities.com/stevemau/slam33page.html " TARGET=_blank>http://www.geocities.com/stevemau/slam33page.html?1004806705410 </A>

09-05-2002, 10:24 AM	#3
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,189	On my Short Bed I used a 1 piece shaft and cut out the hagger for the carrier, BUT on a long bed I think a 1 piece would be too long and you might get wobble at higher speeds. Think It out __________________ 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

09-05-2002, 01:10 PM	#4
sam's 72 Senior Member Join Date: Nov 2001 Location: Pasadena, Texas, USA Posts: 1,005	TTT __________________ 72 LWB chevy truck. Pasadena, Texas

09-05-2002, 04:24 PM	#5
HvyChevy454 Slowly getting CRSS... Join Date: Jul 2001 Location: Lutz, Florida Posts: 656	i saw a lWB at a show that a a 1piece behind a blown 468BB. all he had to do was notch the center loop abount an inch, but he also had what looked to be a 4/6 drop though __________________ -Nic Lutz, Fl My Team Website The Heavy Chevy Website ------------------ 72 Cheyenne 10 LWB GM 12-bolt 3.08 w/ Auburn Posi 91 454 Edel Performer RPM Intake 750 cfm carb Comp Cam 268/.495 Hedman Headers Dual 3'' Exhaust 71 Cheyenne 20 4x4 Fact. A/C PS PB Tilt Currently in the works... Speak Softly and Carry A Big Block... There is No replacement for Displacement... "If everything seems under control, you're just not going fast enough." - Mario Andretti

09-05-2002, 07:52 PM	#6
90\87Formula Registered User $90\87Formula's Avatar$ Join Date: Oct 2000 Location: Abilene Texas Posts: 1,756	Most driveline shops will tell you a one piece driveshaft shouldn't be longer than 6 foot. Longer onepieces will create vibration and eventually failure. It's not necessarilly the diameter, but the wall thickness of the tube. I went from Powerglide to TH400. I didn't cut out the loop ,but I did have to cut out the piece that held the carrier bearing to the loop. I wouldn't cut out the loop, these frames flex enough as it is. Just my .02 cents worth. Good luck, whatever you do. __________________ Robert Member 1532
$90\87Formula is offline$

09-05-2002, 08:00 PM	#7
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	I have a 700R4 in my truck and HAD a 1pc driveshaft. It does whip in the center which gives you a nasty vibration and eventually loosens your pinion nut. Then the nut comes off and the pinion runs into your carrier and makes a really interesting noise. Oh yeah and then it ruins your rear tranny seal also. DO NOT EVER USE A 1 PIECE DRIVESHAFT ON A LWB TRUCK. You will me much happier with a 2 piece. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

09-05-2002, 08:55 PM	#8
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,672	See my replies on this thread: http://67-72chevytrucks.com/vboard/s...threadid=21656 __________________ 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...

09-05-2002, 10:40 PM	#9
Tim Christian Senior Member Join Date: Dec 1999 Location: TN/VA Posts: 6,388	Guys,Guys,Guys About all GMC long wheelbase trucks I have ever seen came factory with a one piece drive shaft. I have owned two of them myself and the drive shaft ran right through the center of the loop from the factory. No whiping, No vibration or nothing. Matter of fact I still have one of the frames laying here in the yard if you would like to see pictures. I also still have one of the factory long one piece drive shafts.



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