Notching the rear cab support for driveshaft - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gottwake · 09-03-2022, 10:35 PM

So after the truck was painted we noticed the driveshaft hits the rear cab support.. anyone have any suggestions on how much to nitch? We're running the porter built rear coilers ...

gottwake · 09-03-2022, 10:36 PM

Here is the rear of the cab

**Richard** · 09-04-2022, 02:00 AM

Do not see a drive shaft in pics posted. Not even sure what is needing space? See some kind of frame brace in front of the aftermarket crossmember that does not look stock. To me it looks like it is installed upside down maybe turn it over? When stuff hits notch as much as needed and provide as much re-enforcement as you think is necessary. Custom fabrication is as needed. I try to make everything as strong or stronger than it was originally. Though it is all garage engineering. So the results may not be as expected.

LS short box · 09-04-2022, 08:26 PM

On my 68 C10 with a 4/6 drop I had to notch the back of the cab for a bit more drive shaft clearance. No big deal. I notched it and touched up the paint. Done deal.

**CC69Rat** · 09-06-2022, 06:15 PM

Just curious, could you adjust the trans mount down a little bit and avoid the need to notch it? What trans are you running? 1 or 2 piece drive shaft? Not challenging, just thinking from a different perspective

LNP · 09-06-2022, 06:24 PM

Quote:

Originally Posted by CC69Rat

Just curious, could you adjust the trans mount down a little bit and avoid the need to notch it? What trans are you running? 1 or 2 piece drive shaft? Not challenging, just thinking from a different perspective

Wouldnt that change u-joint geometry? If yes then he could but then would have to change the pinion angle as well.

**CC69Rat** · 09-07-2022, 09:10 PM

Quote:

Originally Posted by LNP

Wouldnt that change u-joint geometry? If yes then he could but then would have to change the pinion angle as well.

Yes, absolutely. I usually run a 3-4degree pinion shim at around 7" drop (static) and I'm under the impression his truck is pretty low. It may need adjusted anyway? Just thinking I'd rather adjust the trans mount / pinion angle as notch a freshly painted cab. Opinions may differ I guess... just my .02

SCOTI · 09-08-2022, 08:07 AM

From my limited exposure to PB set-ups, they're already about 5° @ the driveline angle so dropping the tail of the trans will only increase that number. They also typically utilize 2pc shaft set-ups which minimize the possibility of interference.

On a one piece shaft, the floor reinforcement channel may need to be clearanced as needed as well as the rear cab wall sheet metal. My old '68 that got PB front + rear kits & utilized a 1pc shaft required notching. Sorry.... no pics though.

LNP · 09-08-2022, 09:25 AM

Quote:

Originally Posted by CC69Rat

Yes, absolutely. I usually run a 3-4degree pinion shim at around 7" drop (static) and I'm under the impression his truck is pretty low. It may need adjusted anyway? Just thinking I'd rather adjust the trans mount / pinion angle as notch a freshly painted cab. Opinions may differ I guess... just my .02

I completely agree. I was just curious if I was thinkin right.

09-03-2022, 10:35 PM	#1
gottwake Registered User Join Date: Oct 2007 Location: Santa Clarita, CA Posts: 581	Notching the rear cab support for driveshaft So after the truck was painted we noticed the driveshaft hits the rear cab support.. anyone have any suggestions on how much to nitch? We're running the porter built rear coilers ... __________________ Blazer Project

09-03-2022, 10:36 PM	#2
gottwake Registered User Join Date: Oct 2007 Location: Santa Clarita, CA Posts: 581	Re: Notching the rear cab support for driveshaft Here is the rear of the cab Attached Images __________________ Blazer Project

09-04-2022, 02:00 AM	#3
Richard Senior Member Join Date: Dec 1999 Location: Southern California Posts: 2,698	Re: Notching the rear cab support for driveshaft Do not see a drive shaft in pics posted. Not even sure what is needing space? See some kind of frame brace in front of the aftermarket crossmember that does not look stock. To me it looks like it is installed upside down maybe turn it over? When stuff hits notch as much as needed and provide as much re-enforcement as you think is necessary. Custom fabrication is as needed. I try to make everything as strong or stronger than it was originally. Though it is all garage engineering. So the results may not be as expected. __________________ Richard 1972 K10 Custom Deluxe SWB Fleetside My build https://67-72chevytrucks.com/vboard/...d.php?t=800746 Last edited by Richard; 09-04-2022 at 02:20 AM.

09-04-2022, 08:26 PM	#4
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 1,923	Re: Notching the rear cab support for driveshaft On my 68 C10 with a 4/6 drop I had to notch the back of the cab for a bit more drive shaft clearance. No big deal. I notched it and touched up the paint. Done deal.

09-06-2022, 06:15 PM	#5
CC69Rat Senior Member Join Date: Jan 2011 Location: Chattanooga TN Posts: 6,205	Re: Notching the rear cab support for driveshaft Just curious, could you adjust the trans mount down a little bit and avoid the need to notch it? What trans are you running? 1 or 2 piece drive shaft? Not challenging, just thinking from a different perspective __________________ Chad 1967 C10 SWB - Project Savannah - 6.0/4L80 Currently underway 1968 C10 SWB - TOTY 2018, 50th Anniversary Tribute Project * Sold * Pride and Joy 1986 Silverado Short Fleet - Scarlet Sold 1985 Silverado Short Fleet Sold 2022 Jeep Gladiator Mojave 2001 Jeep Cherokee XJ 4x4 - Lifted, Built 1992 Jeep Cherokee XJ 4x4 - Lifted 2013 Honda Accord EX-L v6 Coupe 6spd (wife's ride)

09-08-2022, 08:07 AM	#8
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 21,910	Re: Notching the rear cab support for driveshaft From my limited exposure to PB set-ups, they're already about 5° @ the driveline angle so dropping the tail of the trans will only increase that number. They also typically utilize 2pc shaft set-ups which minimize the possibility of interference. On a one piece shaft, the floor reinforcement channel may need to be clearanced as needed as well as the rear cab wall sheet metal. My old '68 that got PB front + rear kits & utilized a 1pc shaft required notching. Sorry.... no pics though. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*



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