rear main seal & torque specs. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sport/Truck · 02-10-2007, 10:36 AM

I’m going to replace the main seal while the engine is out anyone have tricks to doing a leak proof job?
Also need some torque specs for the bolts.
Thanks.
s/t

**clay68c10** · 02-10-2007, 12:23 PM

A tiny bit of silicone on the seal ends and on the main cap mating surfaces at the rear where the pan rubber sits. Also rotate the seal just a bit so it's parting seam doesn't match up with the main cap to block surface.
Someone out there has the torque spec handy....

**kwmech** · 02-10-2007, 12:59 PM

Main caps are usually 65 ft. pnds.

RACINJASON22 · 02-10-2007, 01:05 PM

I agree. Oil on the threads then tighten to 45 ft lb both bolt then 70 ft lb

Sport/Truck · 02-10-2007, 02:12 PM

Looks like I need to pull the oil pump too?? Should I get a new one from napa while I’m at it? Any special instructions to replacing the pump?
Thanks for answering my stupid questions; I’ve never done this before.
s/t

*rage'nrat638* · 02-10-2007, 02:21 PM

for the 35.00 cost i sure would and did. i love new stuff.
nothing like great oil pressure on your engine for piece of mind

Sport/Truck · 02-10-2007, 02:39 PM

Do I need to prime this, or is that only needed on new motors?

Sport/Truck · 02-10-2007, 04:40 PM

Got the main cap off and the seal was installed so that the ends of the seal were the same as the cap (not slightly off centered like it should be). Any way the one under the crank is easily moved seems like it’ll just come right out, but the one on the main cap is glued. Do I need to glue the new one on?
s/t

**kwmech** · 02-10-2007, 07:39 PM

No reason to glue it, just make sure that the lip on the seal is pointing in the correct direction

RACINJASON22 · 02-10-2007, 09:46 PM

I agree seal will go in either way make sure seal lip is pointing toward the inside of the engine.

Sport/Truck · 02-11-2007, 12:58 PM

Do the two ends need any sealant or will they just seal when it’s tightened up?

**clay68c10** · 02-11-2007, 01:12 PM

I've done it with just a miro-spot on the seal ends and without; it didn't seem to make any difference either way.

02-10-2007, 10:36 AM	#1
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	rear main seal & torque specs. I’m going to replace the main seal while the engine is out anyone have tricks to doing a leak proof job? Also need some torque specs for the bolts. Thanks. s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

02-10-2007, 12:23 PM	#2
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,990	Re: rear main seal & torque specs. A tiny bit of silicone on the seal ends and on the main cap mating surfaces at the rear where the pan rubber sits. Also rotate the seal just a bit so it's parting seam doesn't match up with the main cap to block surface. Someone out there has the torque spec handy.... __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ Last edited by clay68c10; 02-10-2007 at 12:23 PM.

02-10-2007, 12:59 PM	#3
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,630	Re: rear main seal & torque specs. Main caps are usually 65 ft. pnds.

02-10-2007, 01:05 PM	#4
RACINJASON22 GEARHEAD Join Date: Jan 2007 Location: CENTRAL,PA Posts: 2,284	Re: rear main seal & torque specs. I agree. Oil on the threads then tighten to 45 ft lb both bolt then 70 ft lb __________________ 72 SWB 2WD MY PROJECT 72 LWB 4X4 FUTURE PROJECT SUBSCRIBE HEREBOARD VENDORS HERE NORWOOD MEET SURVIVOR!

02-10-2007, 02:12 PM	#5
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: rear main seal & torque specs. Looks like I need to pull the oil pump too?? Should I get a new one from napa while I’m at it? Any special instructions to replacing the pump? Thanks for answering my stupid questions; I’ve never done this before. s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

02-10-2007, 02:21 PM	#6
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	Re: rear main seal & torque specs. for the 35.00 cost i sure would and did. i love new stuff. nothing like great oil pressure on your engine for piece of mind

02-10-2007, 02:39 PM	#7
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: rear main seal & torque specs. Do I need to prime this, or is that only needed on new motors? __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe. Last edited by Sport/Truck; 02-10-2007 at 04:43 PM. Reason: Didn’t make sense.

02-10-2007, 04:40 PM	#8
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: rear main seal & torque specs. Got the main cap off and the seal was installed so that the ends of the seal were the same as the cap (not slightly off centered like it should be). Any way the one under the crank is easily moved seems like it’ll just come right out, but the one on the main cap is glued. Do I need to glue the new one on? s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

02-10-2007, 07:39 PM	#9
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,630	Re: rear main seal & torque specs. No reason to glue it, just make sure that the lip on the seal is pointing in the correct direction

02-10-2007, 09:46 PM	#10
RACINJASON22 GEARHEAD Join Date: Jan 2007 Location: CENTRAL,PA Posts: 2,284	Re: rear main seal & torque specs. I agree seal will go in either way make sure seal lip is pointing toward the inside of the engine. __________________ 72 SWB 2WD MY PROJECT 72 LWB 4X4 FUTURE PROJECT SUBSCRIBE HEREBOARD VENDORS HERE NORWOOD MEET SURVIVOR!

02-11-2007, 12:58 PM	#11
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: rear main seal & torque specs. Do the two ends need any sealant or will they just seal when it’s tightened up? __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

02-11-2007, 01:12 PM	#12
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,990	Re: rear main seal & torque specs. I've done it with just a miro-spot on the seal ends and without; it didn't seem to make any difference either way. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ

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