Anybody shorten a driveline? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jwn1975 · 02-05-2008, 09:14 AM

I am in the process of shortning my frame from LWB to SWB. I want to run a straight driveline with no slip yoke. Can I buy a piece of round tubing the correct diameter and thickness and center up the ends I cut off my long drive shaft and weld them on? Any suggestions, balancing, which way to allign the u-joints? I know having one made would be the way to go but im on a budget.

Frizzle Fry · 02-05-2008, 09:16 AM

This is one place you don't want to skimp on. Either find one the right length at a yard (good luck) or get one that's slightly too long and have is shortened and balanced by a shop.

ChevLoRay · 02-05-2008, 09:22 AM

I'm sure it's been done many, many times. Balancing is key to the life of anything in the driveline...u-joints, transmission and rear end, to be sure. The yokes of the driveshaft have to be "phased" properly. Look at the driveshaft you take out and see how the yokes are positioned. The driveshaft you build should be done the same way. After you get it all together, I'd take it to a machine shop, maybe a NAPA shop, and have it spun to check it for balance. If that is the only thing you have done by someone else, assuming you have the talent you need to cut and weld, you'll still save $$. As an aside, here in Central Arkansas, it runs about $75 to have done what you want done, at a business that is in business to do just that.

19673ontree · 02-05-2008, 09:36 AM

I have done this MANY times without any problem ,
it is hard to describe without a picture but I will try

#1 the key to the success is getting the end's plumb (STRAIGHT) (SQAURE)

#2 get a long piece of something straight and clamp it to the end's once you get the length right TEST FIT then TEST FIT IT AGAIN then TEST FIT IT !!!

you will want to use the straight edge ? piece of angle iron ? 2x4 ? just something straight to hold the end's in a nice even form while welding ,
give me a minute and I will make a drawing ,,,,,,,,,,,,,,,,,,,,,,,

19673ontree · 02-05-2008, 09:46 AM

here is a drawing of how to do it , if you do it like this it will not shake , I have done many like this without a problem ,
and just to be saying if you were doing this for a 200 mph race car yes you would need to have it balanced ! for a 1967 to 1972 chevy pickup NO!

crazy longhorn · 02-05-2008, 10:00 AM

I have cut & welded a couple shafts......but i dont reccomend you do it on a shaft That long

crazyL

jwn1975 · 02-05-2008, 11:02 AM

Thanks guys, Ill give "er" a shot and take it to be balanced. I can run a welder and a sawzall. If it wont balance, Ill have them build one.

fullerbuilt · 02-05-2008, 01:28 PM

your rear diff. moves forward and backwards as you roll down the road. you need a slip yoke. or your brgs. will go by,by, and you will hammer your running gear.

jwn1975 · 02-05-2008, 01:33 PM

I have a 67 camaro that doesnt have a slip yoke and everything is OK. I dont plan on hauling anything with the truck nor pulling any trailers. Still have to have a slip yoke?

fullerbuilt · 02-05-2008, 01:50 PM

yep. even with very small movement going on, it is still happening. your parts wont last very long, and your running gear will not be happy.

67_C-30 · 02-05-2008, 02:01 PM

Quote:

Originally Posted by jwn1975

I have a 67 camaro that doesnt have a slip yoke and everything is OK. I dont plan on hauling anything with the truck nor pulling any trailers. Still have to have a slip yoke?

You mean it doesn't have a 2 piece shaft with center slip yoke, but it does have the normal slip yoke going into the tranny right? As long as you have the slip yoke going into tranny you don't need the center yoke on a SWB.

jwn1975 · 02-05-2008, 05:12 PM

Gotcha,
Thanks guys

Longhorn Man · 02-05-2008, 07:57 PM

i would still never build a shaft.
The junk yard has about eleventy billion driveshafts just laying around.

brad_man_72 · 02-06-2008, 10:15 AM

i shorten drivelines everyday, its what i do. believe me save the time effort and money by having a shop that specializes in drivelines build your driveshaft or shorten one that is longer (cheapest route). buy the good u-joints check your pinion angle, and you should have no problems.
even using a lathe, our setups, and making our shafts with about 50% of oem tolerances the shafts can still take quite a bit of weight when in the ballancer.
welding your driveshaft is fine to get your truck out of the field, but not to take down the highway.

02-05-2008, 09:22 AM	#3
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Anybody shorten a driveline? I'm sure it's been done many, many times. Balancing is key to the life of anything in the driveline...u-joints, transmission and rear end, to be sure. The yokes of the driveshaft have to be "phased" properly. Look at the driveshaft you take out and see how the yokes are positioned. The driveshaft you build should be done the same way. After you get it all together, I'd take it to a machine shop, maybe a NAPA shop, and have it spun to check it for balance. If that is the only thing you have done by someone else, assuming you have the talent you need to cut and weld, you'll still save $$. As an aside, here in Central Arkansas, it runs about $75 to have done what you want done, at a business that is in business to do just that. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

02-05-2008, 09:36 AM	#4
19673ontree CAN'T FIX NOTHIN Join Date: Sep 2006 Location: SOUTHRUST VIRGINIA !!! Posts: 2,112	Re: Anybody shorten a driveline? I have done this MANY times without any problem , it is hard to describe without a picture but I will try #1 the key to the success is getting the end's plumb (STRAIGHT) (SQAURE) #2 get a long piece of something straight and clamp it to the end's once you get the length right TEST FIT then TEST FIT IT AGAIN then TEST FIT IT !!! you will want to use the straight edge ? piece of angle iron ? 2x4 ? just something straight to hold the end's in a nice even form while welding , give me a minute and I will make a drawing ,,,,,,,,,,,,,,,,,,,,,,, __________________ 1967 C10 Shortbed Fleetside Small back glass 6 cyl 3spd on the tree 3.08 gears underdash AC

02-05-2008, 09:46 AM	#5
19673ontree CAN'T FIX NOTHIN Join Date: Sep 2006 Location: SOUTHRUST VIRGINIA !!! Posts: 2,112	Re: Anybody shorten a driveline? here is a drawing of how to do it , if you do it like this it will not shake , I have done many like this without a problem , and just to be saying if you were doing this for a 200 mph race car yes you would need to have it balanced ! for a 1967 to 1972 chevy pickup NO! Attached Images __________________ 1967 C10 Shortbed Fleetside Small back glass 6 cyl 3spd on the tree 3.08 gears underdash AC

02-05-2008, 10:00 AM	#6
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Re: Anybody shorten a driveline? I have cut & welded a couple shafts......but i dont reccomend you do it on a shaft That long crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

02-05-2008, 11:02 AM	#7
jwn1975 Registered User Join Date: Jan 2008 Location: Red Lodge Montana Posts: 240	Re: Anybody shorten a driveline? Thanks guys, Ill give "er" a shot and take it to be balanced. I can run a welder and a sawzall. If it wont balance, Ill have them build one.

02-05-2008, 09:14 AM	#1
jwn1975 Registered User Join Date: Jan 2008 Location: Red Lodge Montana Posts: 240	Anybody shorten a driveline? I am in the process of shortning my frame from LWB to SWB. I want to run a straight driveline with no slip yoke. Can I buy a piece of round tubing the correct diameter and thickness and center up the ends I cut off my long drive shaft and weld them on? Any suggestions, balancing, which way to allign the u-joints? I know having one made would be the way to go but im on a budget.

02-05-2008, 09:16 AM	#2
Frizzle Fry Registered User Join Date: Aug 2005 Location: Hillsboro Oregon Posts: 6,449	Re: Anybody shorten a driveline? This is one place you don't want to skimp on. Either find one the right length at a yard (good luck) or get one that's slightly too long and have is shortened and balanced by a shop.

02-05-2008, 01:28 PM	#8
fullerbuilt Registered User Join Date: Jan 2008 Location: plymouth,ca. Posts: 6	Re: Anybody shorten a driveline? your rear diff. moves forward and backwards as you roll down the road. you need a slip yoke. or your brgs. will go by,by, and you will hammer your running gear.

02-05-2008, 01:33 PM	#9
jwn1975 Registered User Join Date: Jan 2008 Location: Red Lodge Montana Posts: 240	Re: Anybody shorten a driveline? I have a 67 camaro that doesnt have a slip yoke and everything is OK. I dont plan on hauling anything with the truck nor pulling any trailers. Still have to have a slip yoke?

02-05-2008, 01:50 PM	#10
fullerbuilt Registered User Join Date: Jan 2008 Location: plymouth,ca. Posts: 6	Re: Anybody shorten a driveline? yep. even with very small movement going on, it is still happening. your parts wont last very long, and your running gear will not be happy.

02-05-2008, 05:12 PM	#12
jwn1975 Registered User Join Date: Jan 2008 Location: Red Lodge Montana Posts: 240	Re: Anybody shorten a driveline? Gotcha, Thanks guys

02-05-2008, 07:57 PM	#13
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Anybody shorten a driveline? i would still never build a shaft. The junk yard has about eleventy billion driveshafts just laying around.

02-06-2008, 10:15 AM	#14
brad_man_72 the boat guy Join Date: Jul 2007 Location: springfield mo Posts: 2,339	Re: Anybody shorten a driveline? i shorten drivelines everyday, its what i do. believe me save the time effort and money by having a shop that specializes in drivelines build your driveshaft or shorten one that is longer (cheapest route). buy the good u-joints check your pinion angle, and you should have no problems. even using a lathe, our setups, and making our shafts with about 50% of oem tolerances the shafts can still take quite a bit of weight when in the ballancer. welding your driveshaft is fine to get your truck out of the field, but not to take down the highway.



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