Dropping oil pan on a 4wd

[SnowDrifter]

Going to do my pickup tube o-ring here soon as part of preventative maintenance. I'm coming up on the mileage where they begin to fail and and well... I'm just going to deal with it before it happens.

Anyways... How do y'all deal with the front diff? Does it need to come all the way out? Or just undo the bushings and let it droop a bit? Trying to see if I need to sync schedules w/ my buddies or not cause pulling the diff all the way out is a fair bit annoying without some extra hands

 

[afpj]

I'm certain you have way more experience than I do, but I have read alot on these forums so not to repeat other's mistakes. Looking through other threads, it seems the consensus is you can unbolt the front diff from the chassis and let it "hang" (with support from a jack), but do not have to unbolt the drive shafts. It's a tight fit getting the oil pan put but doable based on my readings. Just a disclaimer, I've not done this yet so no personal experience, just living vicariously through all the other brave souls who have gone before me. Good luck. I'm sure you've read as well the critical corners of the pan needing some RTV by most who have done it already.

 

[Rocket Man]

I did it on my 02 Denali. Just pull the bolts that hold it to the frame, let it hang, and you might have to pry it down just a bit when pulling the pan in or out. It’s super close but it clears.

 

[SnowDrifter]

Right on thanks! I have a bit of a laundry list of stuff to do. Pretty much a one man job unless I needed to entirely remove the diff - much easier w/ 2 people

 

[latvius]

I just did mine but I also had the transmission pulled at the same time. I just removed the bolts and let it hang as well, had plenty of room. The old gasket has some rivets you need to drill out to remove it.

 

[SnowDrifter]

I just did mine but I also had the transmission pulled at the same time. I just removed the bolts and let it hang as well, had plenty of room. The old gasket has some rivets you need to drill out to remove it.

Yeah I'm not looking forward to the rivet part. The thought it taking a drill bit to my pan makes my skin crawl

 

[Rocket Man]

Yeah I'm not looking forward to the rivet part. The thought it taking a drill bit to my pan makes my skin crawl

1/8” drill bit goes right through the center of the rivet and doesn’t touch the pan. I installed new 1/8” x 1/4” long pop rivets and that holds the gasket in place while wiggling the pan around to install it, so the gasket doesn’t move out of place. Super easy.

 

[latvius]

I just put two bolts thru the gasket, the gasket holds the bolts so pretty easy to line up.

 

[PNWMuseumman]

Lots of good advise in this thread. I did this last fall. The bolts to hold the gasket is a life saver. I was able to remove 2 bolts from the mount on the driver side, and I think 2 nuts off of studs that held it up on the passenger side. Then had to pry a little to get it down, (left it supported by the jack cause it made me a little nervous. and that was plenty of room.

This was on a 02 Z71.

Good luck!

** Did it by myself with the jack. didn't even need the wife to come out and work the jack.

 

[Rocket Man]

I just put two bolts thru the gasket, the gasket holds the bolts so pretty easy to line up.

That might work for a 2WD but for a 4WD with the front diff hanging, there’s no room for bolts to be in the pan while you slide the pan in place. At least I had no room, the pan barely slid in there without bolts sticking up.

 

[latvius]

Mine is 4wd too, but I had trans out. Not sure if that made a difference but I had a good bit of room.

 

[PNWMuseumman]

That might work for a 2WD but for a 4WD with the front diff hanging, there’s no room for bolts to be in the pan while you slide the pan in place. At least I had no room, the pan barely slid in there without bolts sticking up.

↑ This is true, I used the bolts to hold my gasket in place while the thin line of RTV I used dried. Then pulled the bolts out before installing. I don't see how you could get the bolts out once you get the pan back in place.

 

[latvius]

↑ This is true, I used the bolts to hold my gasket in place while the thin line of RTV I used dried. Then pulled the bolts out before installing. I don't see how you could get the bolts out once you get the pan back in place.

Don't know what you mean by "get the bolts out". I put two bolts in the pan thru the gasket and put the pan up against the engine block and screwed in the bolts. Wasn't a big deal, you kind of had to angle the pan a little bit to get it over the front diff.

 

[PNWMuseumman]

Don't know what you mean by "get the bolts out". I put two bolts in the pan thru the gasket and put the pan up against the engine block and screwed in the bolts. Wasn't a big deal, you kind of had to angle the pan a little bit to get it over the front diff.

I was thinking you were putting bolts in through the top, did just the gasket holes hold the bolts in place? I'm not sure if there was enough room (Granted I did not try this, so there totally could have been) to have the body of the bolts in there between the engine and the pan the way I did it. It took some finagling to get the pan in the right place and if memory serves it all but slid along the bottom of the block. But hey if that works more power to you.

 

[latvius]

I was thinking you were putting bolts in through the top, did just the gasket holes hold the bolts in place? I'm not sure if there was enough room (Granted I did not try this, so there totally could have been) to have the body of the bolts in there between the engine and the pan the way I did it. It took some finagling to get the pan in the right place and if memory serves it all but slid along the bottom of the block. But hey if that works more power to you.

Yup the gasket holds the bolts which is really nice! I had my driveshaft removed as well maybe that is why I had more room as far as diff dropping?
Also for the OP you need to put a little bit of gasket sealer in the corners, it's in the GM instructions.