Rear main seal replacement 1979 400
#1
10-22-2018, 11:20 AM
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Rear main seal replacement 1979 400
Replacing the rear main seal on my 400 before I put my rebuilt nv4500 back on it 
and have come into a problem on reassembly. I've got the two piece rope out. The ones I pulled out was definitely a rubber type very close to the felpro unit i bought to put on. The rear main cap parting surfaces didn't have any sealer on them when I took it off. One of my truck manuals has directions on where to put rtv in the parting surface and one doesnt.
Id need some rtv to seal up the parting surface between the seal and oil pan gasket correct? I mean just steel clamped together won't keep oil in the case right?
But on the other hand if this is gonna support the back of my crank shaft then the torque setting is gonna be pretty precise, and the rtv sealing and drying is going to disrupt this.
I couldn't find any anaerobic rtv but I'll just leave the pan off till the main can dry. The one manual has instruction to only use it on a couple parts of the main bearing cap. I'm probably gonna follow the one manual and just use it sparingly. What would you guys do?
and have come into a problem on reassembly. I've got the two piece rope out. The ones I pulled out was definitely a rubber type very close to the felpro unit i bought to put on. The rear main cap parting surfaces didn't have any sealer on them when I took it off. One of my truck manuals has directions on where to put rtv in the parting surface and one doesnt. Id need some rtv to seal up the parting surface between the seal and oil pan gasket correct? I mean just steel clamped together won't keep oil in the case right?
But on the other hand if this is gonna support the back of my crank shaft then the torque setting is gonna be pretty precise, and the rtv sealing and drying is going to disrupt this.
I couldn't find any anaerobic rtv but I'll just leave the pan off till the main can dry. The one manual has instruction to only use it on a couple parts of the main bearing cap. I'm probably gonna follow the one manual and just use it sparingly. What would you guys do?
#2
10-22-2018, 02:17 PM
Replacing the rear main seal on my 400 before I put my rebuilt nv4500 back on it and have come into a problem on reassembly. I've got the two piece rope out. The ones I pulled out was definitely a rubber type very close to the felpro unit i bought to put on. The rear main cap parting surfaces didn't have any sealer on them when I took it off. One of my truck manuals has directions on where to put rtv in the parting surface and one doesnt.
Id need some rtv to seal up the parting surface between the seal and oil pan gasket correct? I mean just steel clamped together won't keep oil in the case right?
But on the other hand if this is gonna support the back of my crank shaft then the torque setting is gonna be pretty precise, and the rtv sealing and drying is going to disrupt this.
I couldn't find any anaerobic rtv but I'll just leave the pan off till the main can dry. The one manual has instruction to only use it on a couple parts of the main bearing cap. I'm probably gonna follow the one manual and just use it sparingly. What would you guys do?
and have come into a problem on reassembly. I've got the two piece rope out. The ones I pulled out was definitely a rubber type very close to the felpro unit i bought to put on. The rear main cap parting surfaces didn't have any sealer on them when I took it off. One of my truck manuals has directions on where to put rtv in the parting surface and one doesnt.Id need some rtv to seal up the parting surface between the seal and oil pan gasket correct? I mean just steel clamped together won't keep oil in the case right?
But on the other hand if this is gonna support the back of my crank shaft then the torque setting is gonna be pretty precise, and the rtv sealing and drying is going to disrupt this.
I couldn't find any anaerobic rtv but I'll just leave the pan off till the main can dry. The one manual has instruction to only use it on a couple parts of the main bearing cap. I'm probably gonna follow the one manual and just use it sparingly. What would you guys do?
I put some on the corners of the rear main seal where the pan would sit. Waited for the RTV to flash (15 minutes-ish), then put the oil pan on and torqued it down. Never had a leak yet.
From my build thread:
#3
10-22-2018, 04:34 PM
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#4
10-22-2018, 04:40 PM
I've never heard of someone using RTV alongside the rear main seal - the rear main seal should be able to do its job all on its own.
#6
10-22-2018, 11:30 PM
Post Fiend
A good how too video this is on a 385 Series the 335 Series (Clevelands) is the same.
Anaerobic sealer
https://www.napaonline.com/en/p/NCB3...archIndex=Prod
Anaerobic sealer
https://www.napaonline.com/en/p/NCB3...archIndex=Prod
#7
10-24-2018, 07:23 PM
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