GM Genuine Parts 12639250 LS Rear Block Cover

This kit fixed my rear main seal leak on my Silverado. My stepdad ordered the same set and we fixed his Cadillac Escalade as well. The upgraded bolts are nice. Some reviews say it is not genuine OEM. I really don't know if it is or isn't. I'm not sure how you can tell but it definitely fits correctly and does the job. It is also easier to do with this kit than swapping the seal without a new housing.

Awesome factory part. Works great on my 2001 5.3 Silverado.

Genuine GM replacement part. Fit perfectly and made repairing the rear engine cover leak a simple process. GM has several EXPENSIVE specialty tools to install the front and rear covers, and oil pan on the LS style engine. I have never used them, and have not had any problems. With the main seal preinstalled, the OE tools would not work anyway. Additionally, the rear main seal can center itself over the rear crank snout, unlike the front cover where it actually seals against the damper pulley, not the crank. The OE method, installs the rear cover without the seal, then installs the seal, so positioning of the cover prior to the seal would be critical.Bolts originally were a 10mm head, revised bolts were a 13mm head.Installation: I applied a small bead of RTV to the joint of the oil pan gasket and the rear of the block on the left and right sides. I positioned the cover with the seal protector still fitted, as the bolts are retained by the cover seal. I worked my way around and started all of the cover bolts and allowed the cover to loosely fit over the crank snout, pushing the seal protector from inside of the seal. Once the cover bolts were finger snug to the back of the engine, I installed the two long oil pan bolts and torqued them to 106 in-lbs. The cover bolts are then torqued to 18 ft lbs. Before doing that, I snugged them all with a socket then loosened the long oil pan bolts to ensure the cover was pulled into place. Then retorqued the oil pan bolts, and then the rear cover bolts in a criss cross pattern.

works great

Do yourself a favor and remove the seal before installing it. Use the rear main centering tool then reinstall the seal otherwise it will more that likely leak as it won't be centered perfectly even tho it kind of centers it self with the seal.that's not good enough some people get lucky but not worth the chance of it leaking again and have to do the job twice.

I liked the fact that this was a new and improved design

This plugged right in on my 2003 Silverado 1500HD 4x4 with 6.0 engine. Easy install of the part itself. Getting to the part and putting everything back took half a day. The bolts on the old part had 10mm heads, this new part has bolts with bigger 13mm heads. Worked great, no more leak.

Didn't need after all but item was of high quality OEM