Another 700R4 Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GlennBrittain · 06-13-2005, 05:15 PM

I have the 700R4 installation complete, with the exception of my tempature gauge. My problem is a leak at the rear tail shaft seal. My transmission builder, a buddy deal, said my front yoke does not go far enough into the transmission. I did measure the distance with my old transmission and with the new transmission installed. The measurements came out to be the 3” noted on several Internet sites on the subject. What I do not know is was the driveshaft the proper length to start with, since the previous owner pulled out the standard and installed the turbo 350.
Does any know what the distance the yoke should be inside the tail shaft? I would like to resolve that issue before replacing the seal. I plan to put my truck back up on stands, scribe the yoke at the seal the drop the driveshaft to see where I am at now. Unfortunately, my tractor is calling me to mow first and it is 101 degrees here today.

72MARIO · 06-13-2005, 05:41 PM

The yoke should be around 3/4" out from the tailshaft of the tranny.

GlennBrittain · 06-14-2005, 11:55 PM

I measured the yoke this afternoon, after running a new wire for my distb. I have 1 1/2" showing. The only other drive shafts I have for comparison are one that was pupped out of a standard and one still installed I6 and standard. If my yoke is the same length as the other shafts I have 2 1/4" inside the tailshaft. After wiping of the leaking fluid and watching, it looks like the leak is between the outer edge of the seal and the shaft housing.

**Hart_Rod** · 06-15-2005, 07:25 AM

3/4 to 1 inch should be good.

Rob

GlennBrittain · 06-15-2005, 10:11 PM

Thanks for the info

Harold Shepard · 06-15-2005, 10:20 PM

The trans length on a three speed manual and th350 are the same length so you should be good on length, unless long shaft th350 .

BubbaGreen · 06-15-2005, 10:35 PM

FYI: some of the 700R4, the ones from cars are sometimes fitted with a "short" splined output shaft, the ones from trucks have "long" splined shafts. For the short version, its better to use the same yoke as a TH-350 trans. 1-1/2 out seems too far. 3/4 to 1" is correct. If the trans is used, it could be that the pressed in bronze bushing in the tail shaft itself is worn or the seal needs replaced.

1-PU70 · 06-16-2005, 10:33 AM

If you replace the seal I would replace the bushing too or you just might be wasting your time.

06-13-2005, 05:15 PM	#1
GlennBrittain Senior Member Join Date: Jun 2003 Location: Panola County Texas Posts: 401	Another 700R4 Question I have the 700R4 installation complete, with the exception of my tempature gauge. My problem is a leak at the rear tail shaft seal. My transmission builder, a buddy deal, said my front yoke does not go far enough into the transmission. I did measure the distance with my old transmission and with the new transmission installed. The measurements came out to be the 3” noted on several Internet sites on the subject. What I do not know is was the driveshaft the proper length to start with, since the previous owner pulled out the standard and installed the turbo 350. Does any know what the distance the yoke should be inside the tail shaft? I would like to resolve that issue before replacing the seal. I plan to put my truck back up on stands, scribe the yoke at the seal the drop the driveshaft to see where I am at now. Unfortunately, my tractor is calling me to mow first and it is 101 degrees here today.

06-13-2005, 05:41 PM	#2
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	The yoke should be around 3/4" out from the tailshaft of the tranny. __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD

06-14-2005, 11:55 PM	#3
GlennBrittain Senior Member Join Date: Jun 2003 Location: Panola County Texas Posts: 401	I measured the yoke this afternoon, after running a new wire for my distb. I have 1 1/2" showing. The only other drive shafts I have for comparison are one that was pupped out of a standard and one still installed I6 and standard. If my yoke is the same length as the other shafts I have 2 1/4" inside the tailshaft. After wiping of the leaking fluid and watching, it looks like the leak is between the outer edge of the seal and the shaft housing. Last edited by GlennBrittain; 06-14-2005 at 11:56 PM.

06-15-2005, 07:25 AM	#4
Hart_Rod ************* Join Date: Apr 2005 Location: Pensacola, FL Posts: 17,858	3/4 to 1 inch should be good. Rob __________________ Rob - https://www.instagram.com/hart_rod_c10 As Iron Sharpens Iron, So One Man Sharpens Another. Proverbs 27:17 FOR SALE: DBW pedal bracket - http://67-72chevytrucks.com/vboard/s...d.php?t=651123 FOR SALE: Hood Brackets http://67-72chevytrucks.com/vboard/s...d.php?t=679945 1987 Silverado SWB - 34.5K original miles http://67-72chevytrucks.com/vboard/s...d.php?t=801834 1969 SuperBurb - http://67-72chevytrucks.com/vboard/s...d.php?t=200387 1968 Farm truck - http://67-72chevytrucks.com/vboard/s...d.php?t=358692 1968 SWB - http://67-72chevytrucks.com/vboard/s...d.php?t=551258 1948 Chevy - http://67-72chevytrucks.com/vboard/s...=122164&page=3

06-15-2005, 10:35 PM	#7
BubbaGreen Senior Member Join Date: Mar 2001 Location: Cedar Park, TX Posts: 686	FYI: some of the 700R4, the ones from cars are sometimes fitted with a "short" splined output shaft, the ones from trucks have "long" splined shafts. For the short version, its better to use the same yoke as a TH-350 trans. 1-1/2 out seems too far. 3/4 to 1" is correct. If the trans is used, it could be that the pressed in bronze bushing in the tail shaft itself is worn or the seal needs replaced. __________________ 71 Chevy C-10 SWB Fleetside RamJet-350/4L60e & Compushift/3.73Posi See it at www.prismnet.com/~grzanich

06-15-2005, 10:11 PM	#5
GlennBrittain Senior Member Join Date: Jun 2003 Location: Panola County Texas Posts: 401	Thanks for the info

06-15-2005, 10:20 PM	#6
Harold Shepard Registered User Join Date: May 2004 Location: Canton North Carolina Posts: 466	The trans length on a three speed manual and th350 are the same length so you should be good on length, unless long shaft th350 .

06-16-2005, 10:33 AM	#8
1-PU70 Registered User Join Date: Apr 2000 Location: Bradenton, FL Posts: 1,036	If you replace the seal I would replace the bushing too or you just might be wasting your time. __________________ 1970 CST/10 402,700R4,3:73 posi,AC,PS,PB,TLT,PW,Buckets with heaters

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