removing Oil Pan from Hell

aspevacek

Original poster
Member
Jul 4, 2012
11
Ok so I do not own a Trailbalzer. But have worked on BMWs for years. The design used on the oilpan with the Diff is nothing new to me. The design is very much a european design. BMW had used a very simular design in the 80 on the E30 body style. The big difference is I usually went after removing those pan because of a pan gasket leak. This time on the Chevy I am attempting to pull the pan to access a failed Timing chain tensioner. I have the Disconnect removed from the passanger side of the pan. But the diff will not even budge with all the bolts removed. I have pryed on it for a few hours today. The disconnect on the passanger side was stuck in the hole and took a while to remove as well.

My big question is how hard is it to locate a 4.2l AWD oilpan? My plan tommorow is to destroy the oil pan if it does not let go of the Diff. I figure the pan has to be alot cheper to get then a Diff.
 

tricguy007

Member
Dec 7, 2011
131
I would go and spray the sh*t out if it with PB blaster or wd-40 tonite and let it set overnite then try in the morning to remove it
 

Bartonmd

Member
Nov 20, 2011
545
You're sure you have all the bolts out of the diff? IIRC, there's one that isn't obvious, and maybe it's coming from the other direction? I don't remember, exactly, but make sure you REALLY look around for all the bolts, and make sure they're all out.

Mike
 

aspevacek

Original poster
Member
Jul 4, 2012
11
soaked it for 8 hours in PB blaster. All of the bolts are out it looking with a mirror. Based on how the Diff is bolted in with oil pan bolts above it I would say it is not possible to have otehr bolts entering it from the other side. I have even shot the PB blaster thru the tube the intermidiate shaft goes thru. The truck is located in PA has seen it sshare of snow and salt on the roads. The issue is one I have seen many BMW wheels. 2 pieces of metal and they failed to put any kind of anti seize in there. so you get th ecorrosion forming a bond almost like glueing the pieces together. Happens alot on BMW's with the rims because alot of tire shops clean the Antiseize off the hubs and rims.

Before flat destroying the pan this morning I am going to allow it 1 hour to come apart. I spent entirely too long in the heat yesterday and about 5 of it was trying to be gentle so I did not hurt the pan or the diff.
 

Bartonmd

Member
Nov 20, 2011
545
aspevacek said:
soaked it for 8 hours in PB blaster. All of the bolts are out it looking with a mirror. Based on how the Diff is bolted in with oil pan bolts above it I would say it is not possible to have otehr bolts entering it from the other side. I have even shot the PB blaster thru the tube the intermidiate shaft goes thru. The truck is located in PA has seen it sshare of snow and salt on the roads. The issue is one I have seen many BMW wheels. 2 pieces of metal and they failed to put any kind of anti seize in there. so you get th ecorrosion forming a bond almost like glueing the pieces together. Happens alot on BMW's with the rims because alot of tire shops clean the Antiseize off the hubs and rims.

Before flat destroying the pan this morning I am going to allow it 1 hour to come apart. I spent entirely too long in the heat yesterday and about 5 of it was trying to be gentle so I did not hurt the pan or the diff.

No, you're right. We started by splitting the thing in half and pulling out the differential first, then taking the inner housing off by itself. There are bolts from the back side holding the halves together, is what I was thinking of.

Mike
 

Mooseman

Moderator
Dec 4, 2011
25,561
Ottawa, ON
Just an idea, maybe try to rotate the diff in the pan to work out the corrosion between the oil pan and diff. Maybe a little heat from a propane torch to expand the pan a bit might help. You should be able to find a used pan somewhere at a reasonable price if you do wind up thrashing it.
 

aspevacek

Original poster
Member
Jul 4, 2012
11
we found a pan at a local scrap yard for $100.00. The diff is seized in there. I would call this a 100% mess up on GMs part not putting a little antiseize in there at the factory. The truck is located in PA and has seen its share of snow and salt over the years. You can not get the diff to move in any direction so we are cutting the pan ou tin a chunk to get the diff on the ground where i can play with heat and what ever else i see fit to use on it. The same yard that has the pan for us also has a diff with 3.73 gears in it like the current unit for $500.00 if something goes wrong while i am working the chunk of pan over. All this because of a failed timing chain tensioner. The kicker to all of it is my aunts 2005 chevy Aveo had a timing belt fail so I had to take 2 hours today to snatch the head off her car, so I can rebuild it and get her rolling along as well.

I do thank yall for the input on this one but that diff is not going to give up with out a fight is what it seems to me.
 

aspevacek

Original poster
Member
Jul 4, 2012
11
Mooseman said:
Just an idea, maybe try to rotate the diff in the pan to work out the corrosion between the oil pan and diff. Maybe a little heat from a propane torch to expand the pan a bit might help. You should be able to find a used pan somewhere at a reasonable price if you do wind up thrashing it.

My idea fist thing this morning was to put a jack under the front end of the diff and one under the read end and try to pivot it a bit to get it to brake the corrosion. All it did when we applied pressure to the jack was start to lift the truck off the jack stands. So we lowered it and tried at the back end of the diff and the same thing happened. Most I can hope for is after we cut the section of Pan out is to use the die grinder and get the pan thin enough it will just fall off.
 

Mooseman

Moderator
Dec 4, 2011
25,561
Ottawa, ON
Anti seize is not in their vocabulary. In fact I have never seen it used by an oem. Why stop an income stream from seized and broken parts?
 

Gordo

Member
Mar 26, 2012
81
Just went through this same mess when I swapped out the engine on my 02 Envoy. I finally got both sides out of the original pan, with the engine on the bench, every wedge I owned, lots of penetrating oil, heat, at least a case of beer and a bottle of rum. I had so much tension on it at times, I was sure I was going to crack it. Once I saw movement, it got easier. Turns out I had to do this as my "used" engine had a broken half in one side. The auto wrecker had already sold the "good" pan. I did not know what I was looking at at the time. Long story short, I now have a spare pan! I'll sell it if someone is stuck!

Gordo
 

aspevacek

Original poster
Member
Jul 4, 2012
11
well I decided ot sleep in today and my little brotehr being as impatient as he is drug a torch under the the truck and decided the heat was going to make it let go or he was going to burn the truck down trying. Well the short version is he heated th eparts alot hotter then I would advise but the diff popped right out after he was under there for about 15 minutes putting heat to what ever he came across. So the pan was saved and short of a seal the diff was as well.
 

Irishboy02

Member
Apr 1, 2012
222
When I removed my oil pan, engine was out of the truck, there were two bolts , i believe rear driverside of the block IIRC, that were threaded with the oil pan. Had to sit there with an open ended wrench and crank it 1/4 of a turn - took like 20-25 min. As this bolt loosened, it dropped the pan out. Might be tough to see since the motor is still in. Maybe try to loosen the motor mounts and jack the front of the motor up to give you a little wiggle room in there. I am going to dig for my progress pics during my rebuild.
 

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