mikear

Any recommendation on differential covers? I hear a lot of guys talking about mag hytec, but I’m not looking to spend that kind of money. Just seems like a machined gasket surface would seal better than these factory covers. I will definitely be grabbing a lube locker gasket.

Thank you for the information. It makes perfect sense. However, the factory differential cover isn’t flat on the gasket sealing surface due to some indentations between the bolt holes. It may not be easy to straighten out. Would it just be easier to replace the cover? My fear is that if I mess with it and it leaks, I’ll be changing the oil for a 5th time instead of 4th.

I used Fel-Pro gaskets. Not real sure how to accurately check flatness in my garage though. And if it was not flat, then get out the hammer? I did clean the surfaces of gasket very well, including hitting them with steel wool. I don’t mind paying for a better gasket. Honestly, I’ve never heard of lube locker before. Are these gaskets thicker to fill a void that my cover apparently has? Thanks guys

Hey guys, new here so please bear with me. I have a 2006 Silverado Z71 with a G80 rear differential. I bought the truck new and she just rolled over to 239k. Anyhow, I was changing front and rear differential fluids two weekends ago because it was time. Now I have an issue. Try #1 - I drained the rear diff and replaced the gasket. I torqued the cover down to 30 ft/lbs using a star pattern and filled it to 5/8” below the fill hole. I messed it up this time because I had rolled the top of the gasket over and didn’t realize it until later that day. Try #2 - After I noticed it was leaking I picked up a new gasket and drained it again. I used a small amount of Permatex aviation gasket maker to hold the gasket in place, being very careful to line everything up. Reassembled everything, went for a short drive, and re-torqued. All looked ok so I took about a 150 mile round trip. I noticed a small drip forming at the bottom of the cover when I had parked in the driveway. Cleaned it up real well with B12, rechecked torque, and drove it a little more. Same thing. At this point I questioned my use of the gasket maker in tandem with a gasket. Try #3 - So yesterday I changed the oil and gasket again, this time without gasket maker. Torqued it back down, took it for a spin to warm it up, then re-torqued. Everything seemed good so I went fishing, pulling the boat around 30 miles round trip. Last night when I got home I noticed there was once again a droplet forming at the bottom of the cover at the gasket. Checked torque, all was good. Cleaned it up again with B12 and today, same thing. What gives? Could my factory differential cover be slightly warped causing a poor seal? Could rolling the gasket the first time and torquing it down have caused this warp since it would have been an uneven sealing surface? I never had a leak prior to changing the fluid. This is getting expensive at $13/qt of Mobil 1 75W90. Thanks in advance, Mike