2014 6.2 Rear main seal leak
06-07-2024, 09:14 AM
#1
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2014 6.2 Rear main seal leak 2014 Yukon Denali XL 1500 2WD 6.2 w/tow package.
Rear main seal was leaking, had son's transmission friend pull tranny, put in new seal and cover plate gasket. I helped so know it was torqued correctly. Drive 45 miles still leaking ,1 week later pull it again this time I bought all new cover plate, gasket, seal and new hardware from DEALER. Drive 20 miles ,still leaks. Get mad and take it to Reputable business, 12 months 12k miles warranty. Explain everything to them. They remove my cover plate and install ANOTHER new setup. They say it is fixed, I get home (20 miles) and still leaking. they take it back and pull transmission 3 more times, still leaking . they used smoke to try to find leak says it is coming thru fly wheel bolt holes , so they use sealant . no good. They mounted dial indicator on engine block and checked run out on shaft flange and it is good. Now they suggest another engine $10k ain't happening. I have the skills to rebuild from scratch my self. but, would like to figure out why it continues to leak. When first started it has 60psi oil pressure, after warm and driving drops to 40psi at stops and idle it is at 20psi.
More info
Dropped #7 lifter 2 months ago, did a AFM/DOD delete. Put in stock cam and new lifters , new timing chain and new high volume oil pump. Used blind rivets and blocked off the 8 oil ports that went to old VLOM plate and removed and capped off oil pressure relief valve in oil pan and put in NEW blank VLOM plate. Per Summit Racing . Any knowledge would be helpful, before I pull this engine.
Rear main seal was leaking, had son's transmission friend pull tranny, put in new seal and cover plate gasket. I helped so know it was torqued correctly. Drive 45 miles still leaking ,1 week later pull it again this time I bought all new cover plate, gasket, seal and new hardware from DEALER. Drive 20 miles ,still leaks. Get mad and take it to Reputable business, 12 months 12k miles warranty. Explain everything to them. They remove my cover plate and install ANOTHER new setup. They say it is fixed, I get home (20 miles) and still leaking. they take it back and pull transmission 3 more times, still leaking . they used smoke to try to find leak says it is coming thru fly wheel bolt holes , so they use sealant . no good. They mounted dial indicator on engine block and checked run out on shaft flange and it is good. Now they suggest another engine $10k ain't happening. I have the skills to rebuild from scratch my self. but, would like to figure out why it continues to leak. When first started it has 60psi oil pressure, after warm and driving drops to 40psi at stops and idle it is at 20psi.
More info
Dropped #7 lifter 2 months ago, did a AFM/DOD delete. Put in stock cam and new lifters , new timing chain and new high volume oil pump. Used blind rivets and blocked off the 8 oil ports that went to old VLOM plate and removed and capped off oil pressure relief valve in oil pan and put in NEW blank VLOM plate. Per Summit Racing . Any knowledge would be helpful, before I pull this engine.
06-07-2024, 09:19 AM
#2
Has anyone actually determined that it's leaking at the rear main seal? Like with the oil UV dye? It sounds like the same part is being replaced but the leak may lie somewhere else? That's a lot of the same part being replaced...
Could be the oil pressure sender leaking above and oil making it down appearing it's the rear main seal. IDK
Could be the oil pressure sender leaking above and oil making it down appearing it's the rear main seal. IDK
06-27-2024, 03:09 PM
#4
Probable cause.... I didn't read that anyone use the proper tool to Center the rear cover. If you just bolt it on without ensuring it's centered, it will definitely leak. Also, if I remember correctly there was a TSB about some of the aluminum blocks were seeping oil on the rear pretty close to where the rear cover seal is. The official fix is to lightly smear RTV over that area.
And was there a groove in the crankshaft from the old seal? The factory seal is installed flushed with the outside of the cover. But you can install the replacement seal further in, bottoming it out, effectively relocating the place on the crankshaft the seal rubs. And the rear main is to be installed dry. If you Lube up the crank before installing the seal.. I hear that it's a guaranteed leak. Something to do with the Teflon design of the seal.
And was there a groove in the crankshaft from the old seal? The factory seal is installed flushed with the outside of the cover. But you can install the replacement seal further in, bottoming it out, effectively relocating the place on the crankshaft the seal rubs. And the rear main is to be installed dry. If you Lube up the crank before installing the seal.. I hear that it's a guaranteed leak. Something to do with the Teflon design of the seal.
06-27-2024, 08:29 PM
#6
Are you sure the pcv valves in the valve covers aren't clogged causing excessive crankcase pressure to blow out the rear main? I have seen the exact issue at the dealer quite a few times and the first seal to go is almost always the rear main, sometimes the lip of the seal is visibly flipped and blown out. Plugged pcv valves would explain why every time it is replaced it very quickly begins to leak again over and over.
