Erick C.

I just finished up doing the AFM/DOD delete on my 2013 GMC Yukon Denail and it seems i have a front crank seal leak. When installing the new OEM seal and balancer, i did not put any sealant on the outside of the seal or grease the inside of the seal prior to the balancer installation. 3 questions: 1. Upon re installation of the seal, is common practice to put sealant on the outside and grease or oil the inside? 2. Are there any best practices to hold the crankshaft still while we tighten the bolt outside of wedging a pry bar in between the balance? If i can stick pry bar in the sprocket of the flywheel, will that be able to take the torque needed to fully tighten down the crank bolt? 3. I bought an ARP bolt this time around. The ARP website says to torque to 235 ft lbs, is that correct? That seems like an awful lot. Any help is appreciated. I cleaned up all the excess oil and verified the leak was coming from the seal, i have included a picture.

Yea, I took it out yesterday. Apparently when I put it back in the new valley pan I didn't seal the threads. I wrapped it with Teflon tape, put it back in, roughly clean the stuff under the car with brake cleaner and took it for about a mile test drive and had a little more oil pressure (was right below 40 from a cold start, now its right above 40) then let it sit overnight. I checked this morning and it looks like there may have been a few drops from the front seal which I know about but not a stream like before in the middle of the truck. I included pictures of what it look like around it before and after. I'll take it on a longer drive later and make sure everything is good to go. Now to figure out the front seal. Baby steps! Haha

I swapped over the oil pressure sending unit to the new vlom. Is it possible that it is causing the leak down the pain and to the middle of the truck?!

We were able to slap everything back together and I reprogrammed the truck to remove the AFM/DOD. Truck fired right up and runs great however now I have a lil leak. It drips right under the pulleys and looks like the main seal may be leaking and then there is a stream where it seems to run down the oil pan, I'm not sure if it's 2 leaks or 1. We did not replace the oil pump, timing chain or chain tensioner. I did loosen one of the oil pan bolts not paying attention when trying to remove a wire bracket under the bottom of the timing chain cover and front of the oil pan, then tighten it back. Gaskets that were replaced: Main crank seal Timing cover gasket Water pump gasket new VLOM with new gasket Head gaskets Valve cover gaskets Intake manifold gasket Exhaust manifold gasket I've read it is tough to get the main crank seal right and I'm not sure if ruined the oil pan gasket by loosening that one bolt. I've been debating running blue devil oil stop leak through the system but I want to verify where the leak/leaks are coming from. I included a picture from my floor from the past few days. The few drops at the front seem like they're from the balancer area and the stream seems like it just runs down the oil pan and drops in random spots. Again, thanks for the help so far

Update, we got the old camshaft out and one of the lobes was chewed up. We got everything tore apart and the new camshaft put in, put the timing chain cover on and the harmonic balance back end and we realized we took the oil pump bolts out and did not put them back. So now we have to pop the harmonic balance and timing cover back off to put those bolts back in. Question - we were in the process of torquing down the balancer bolt when we had to back it out. My question is, can I reuse it since we hadn't completely tightened it down yet?!

Im still in the middle of tearing this thing apart (Working on it like 2 hours a day) and i was just curious, will i need to take the A/C Condenser out to slide the camshaft out or should their be enough room when i pull the radiator and radiator fan?

Yea, looking at it again and watching a few videos I see you can remove the radiator and radiator fan and have plenty of room to remove the camshaft. I've decided to do the AFM dod delete. I've taken the intake, coil packs, valve covers, plug and wires out today. I'm gonna work on the heads, water pump, radiator, radiator fan and all the timing stuff over the next few days while I wait on the parts to come in. I'm gonna order the kit with the Diablo programmer so I can reprogram it when I'm done. My intent is to fix this and keep it til the wheels fall off so I'm really hoping this completely fixes the issue. My father in law had a 2000 suburban that had 250k miles on it before he got rid of it so I thought I was getting a beast of a vehicle.. turns out that started to torch the brand with these AFM lifters.

Thanks, its the same exact sound as it was before. I was debating replacing that one lifter again on the possibility that it just may be another bad lifter. I attached a picture of what i could see of the camshaft of cylinder 6 where the AFM lifters go (not sure if you want see what i saw but it doesn't look bad) The left side there was no issues, the right side is where the lifter failed. If i do replace the lifter only and buy the AFM/DOD bypass that goes into the OBDII port, could it keep that lifter from going bad or would i be better off just doing the AFM/DOD delete? Sorry for all the questions, i just want to make sure i explore all my options. Just trying to prepare for if i have remove one head like before or if im gonna have to pull both heads and then pull the motor out to replace the camshaft for the AFM/DOD delete. Thanks for the advice.

I am new to the forum. I have recently experienced the infamous stuck lifter on cylinder 6. It sounded like a bolt was rattling around in the engine. After doing some research, we proceeded to take the valve cover off to validate the rocker arm did not move after cranking the truck that would further indicate a stuck/collapsed lifter. I ordered all the parts to do the lifter replacement for all 4 AFM lifters on the passenger side since we had to take the head off. When we removed everything, the lifter roller didnt seem to scored up and we rolled the camshaft to see if there was any damage but it didnt seem super concerning. I could not tell there was anything wrong with the lifter when i removed it based on trying to compress it and it did not physically come apart. I could put the lifter in the old lifter guide and spin it, where as the new lifter guide had grooves that held the lifter in place (not sure what would cause it to seize up and strip the notches on the lifter guide.) When replaced all 4 AFM lifters, new valve guides, head gasket, intake gasket, exhaust manifold gasket, new head bolts and new exhaust manifold bolts (old ones were crap.) The truck fired up and ran really well for about 50 miles or so and the same thing has occurred. I have pulled the valve cover(haven't pull the head or anything yet) to make sure its sticking again. My question is, what may cause the same lifter to fail that quickly? and should i just go ahead and do the AFM/DOD delete, would that solve my problem? I was thinking of going with this kit. https://www.amsracing.net/collections/gm-afm-dod-kits/products/complete-active-fuel-management-afm-dod-delete-kit-w-handheld-for-2010-2014-gm-chevrolet-6-2l-l94-engines-8th-digit-vin-f Any help is greatly appreciated.