NineZeroFive

After searching extensively and finding no real comprehensive “how-to” oil pan/gasket swap, I decided to document my experience a little in the hope it helps someone else. This was just how I did it and others may have more info to share. I decided to tackle this while doing LT/motor mounts, apparently that wasn’t hard enough haha. I noticed leaking along my bellhousing and all around my pan. I checked behind my intake and confirmed it wasn’t coming from above the pan before doing this. Let me begin by saying that this will not be over quickly, you will not enjoy this. Be organized, put bolts in plastic bags and mark where they came from. Mine went from a gasket swap to a pan swap because I followed some bad online torque specs and stripped one of the bellhousing to oil pan bolts. Speaking of bolts, I’m not sure what was going on with my factory ones but they were brittle as hell, probably due to heat from my old long tubes. I snapped a small closeout bolt with almost no torque whatsoever. At that point, I ordered all new 10.9 zinc plated bolts from boltdepot.com (except oil pan bolts, those came from ARP). Overkill? Yes but overkill, as they say, is underrated.




Engine brace fromHarbor Freight ($70), High temp RTV, new pickup tube O-ring, pan gasket or Oil pan (GM part #12558899).


OPTIONAL: Highly recommend new oil pan bolts. Just the idea of snapping the two 8mm rear skinny ones scared the hell out of me so new ones bought me piece of mind. Others have gotten away with the original ones though.


OPTIONAL: Oil filter fitting (GM part #12552357). If you order a new pan, be advised GM decided to change the oil filter fitting to an M20x1.5, requiring a different filter. This replacement fitting allows you to use the standard F-body filter, assuming you can’t remove the one from your old pan for some reason (like me, who threw away his old pan before realizing GM made the change…sigh).





1) Start by disconnecting the battery, removing your front tires and jacking up your car front and back so it’s pretty level. Then remove your front sway bar and set aside. This will free up a lot of much needed room. Drain your oil and remove filter. While it’s draining, remove your lid, serpentine/ACbelts, alternator/bracket, disconnect the oil level sensor harness from the side of the pan, and remove the five bolts holding AC compressor/bracket. Bungee or zip tie AC compressor out of the way and set the bracket aside. This will give you room to work at the front of the pan and allow you better access to the motor mounts. Make sure your wheel hubs are straight and disconnect the steering shaft, starting with the bolt at the top and then the bolt at the bottom where it connects to the rack. You’ll want to start the removal at the bottom, and will probably need a flat head screwdriver to pry it upwards initially to get it off the rack and then you can slide it down and out. Remove the single nut holding the transmission to the crossmember (it’s directly in the middle, in a recessed hole) for preparation in lifting the engine/tranny.


2) Place a jack under your oil pan with a piece of wood between to protect the pan. Raise the jack until it just barely takes theweight of the engine. At this point, decide how you are going to disconnect the motor from the K member. You could remove the single large bolt on either mount or remove the bolts holding either the clamshell or pedestal. Your call, whichever allows better access will likely make up your mind for you. Once this is done, raise the engine until the intake nearly touches the cowl. The tranny will limit this for you as it touches the transmission tunnel. Take your Harbor Freight engine brace and secure the engine. I attached it to the motor mounts and made damn sure it was secure (shake it hard to verify). You can now remove the jack and move on to the K member.





3) Disconnect the lower portion of the shocks where the two bolts attach to the K member. At this point you can see the two large bolts/nuts that hold the rack to the K member. Remove the bolts to free it up. Now look for the 6 large bolts that secure the K member to the body. There are 3 on each side. The two bolts towards the front of the car are long, the rear most one is short. Remove the very front one and the short rear one on each side. Now take the long one and thread it three or four rotations into the rear hole (phrasing) as thiswill hold the K member up as you remove the final middle bolt. At this point the engine should be as high as it will go and the K member should be dropped a few inches.







4) Unbolt the two plastic covers on either side of the oil pan (GM calls these “closeouts”) held by a single bolt. Before you start unbolting the pan, look for two little metal nubs sticking down between the bolts. One will be next to the oil filter location and the other is on the passenger side near the front. These are the bottom parts of the infamous rivets that secure the old gasket to the pan. Take a flathead screwdriver and hammer and knock the nubs off. This frees up the rivets from the pan and allows you to remove the gasket with a little persuasion later on. Now unbolt the two large bolts at the bottom of the bellhousing that connects to the pan before removing the two skinny 8mm bolts at the rear of the oil pan. Now start removing all of the 10mm bolts around the pan.














5) The pan should drop several inches and allow access to the oil pickup tube. It’s secured by one 10mm bolt at the front and a 13mm nut at the rear. If you are only wanting to swap the gasket without removing the pan, this part can be nerve-wracking. I started by breaking each loose before using a pen magnet held nearby while I finished removing it to catch it in case I dropped it. Just go slow and it’s not too bad. Once both are removed, you can lower/drop the pickup tube, taking care to remove theO-ring from the pickup tube (note its location on the tube).

NineZeroFive

6) Use a small prybar or screwdriver to pry up the two rivets and remove each from the pan without dropping them into it. Once this is done, you can easily fish the old gasket out from between the pan and block toward the front of the car. It might help to support the pan with a stand to keep it level while you do this as it usually wants to tip rearward. Use a razor to scrape the two surfaces clean if it needs it. Now take the new gasket and fish it into place, using a couple bolts through the pan to orient/hold it. Take some high-temp RTV and run a thin bead where you see the front and rear covers meet the block. Don’t over-do it, just enough to fill in the small gap. Now thread all your 10mm panbolts finger tight only! Grab your two large bellhousing to pan bolts and thread them both before torqueing them to 35ft/lbs (4L60E). If you have something else, look up the proper spec. Torqueing these while the other bolts are finger tight allows the pan to sit perfectly flush with the bellhousing. Now thread the skinny 8mm bolts finger tight and begin torqueing the 10mm bolts to 18ft/lbs and finally the 8mm bolts to 9 ft/lbs. I did two passes, marking a dot next to each bolt with a sharpie each time to make sure I didn’t miss one.













6a) Find the metal bracket that holds the metal brake lines along the driver’s side inner fender. It’s held in place by a single bolt (10mm, I believe). Remove the bolt and the one remaining K member bolt on the driver's side. You can now push the entire driver’s side of the K-member toward the front of the car, allowing you to just get the pan free from between the tranny and K member. It’s possible you may have to also remove your driver’s side header, depending on the type and size you’re running. Mine was already off at this point but I really didn’t need too much lateral room to free the pan. Now take the oil filter fitting off your old pan using a hex key.


Remove the oil filter fitting from the new pan with a 15/16”socket. Replace with the standard F-body fitting. Now’s a good time to clean the mating surface on the bottom of the block. I used a razor blade. Push the K-member forward again and put the pan into position.


Take some high-temp RTV and run a thin bead where you see the front and rear covers meet the block. Don’t over-do it, just enough to fill in the small gap. Now thread all your 10mm pan bolts fingertight only! Grab your two large bellhousing to pan bolts and thread them both before torqueing them to 35ft/lbs (4L60E). If you have something else, look up the proper spec. Torqueing these while the other bolts are finger tight allows the pan to sit perfectly flush with the bellhousing. Now thread the skinny 8mm bolts finger tight and begin torqueing the 10mm bolts to 18ft/lbs and finally the 8mm bolts to 9 ft/lbs. I did two passes, marking a dot next to each bolt with a sharpie each time to make sure I didn’t miss one.















Now reassemble everything, replace filter, fill with oil and check for leaks before and after starting it up. Job done!

Darth_V8r

iTrader: (4)

Very nicely done, sir! Always appreciate someone taking the time to contribute in a positive way.

In the past, I've always referred people to a sticky "How TO change connecting rod bolts with motor still in the car" and just tell them to stop before changing the connecting rod bolts.

Also, while you have the K down, its a good chance to go to a tubular K, which makes the oil pan much more easier.

NineZeroFive

Thanks! Yeah I'd like a tubular k member someday when I can afford it. This way let me fix my leak without messing with my alignment, so that was a nice bonus.