[zippy]

How much am I gona wana shoot myself in the face if I try to replace pan gasket in frame on my TA? I am sure gona have to lift engine a bit. But how much?

It's just quite a chore to pull engine in my small shop. Headers and all. Just put in last year. Pan is leaking at rear main cap. No oil on flexplate or crank end. But oil sure getting flung around the th400 bellhousing and onto my pass header. Causing smoke and smell all the time. No dust cover over the flexplate and it's driving me nuts

Any tips be really appreciated

[mgarblik]

When I worked at the Pontiac dealer, I did allot of oil pan gasket replacements, in the chassis. Many under warranty. Pontiac's are leakers for sure. I would not attempt to do a pan with the car on the floor. You really need a lift so you can work the pan out and back in without ruining the new gasket, especially the rear rubber or cork seal. When I did them on a 2nd gen car, I unbolted the fan shroud so it was loose under the hood, removed the distributor as well. No way the pan is coming out with an HEI in there. Even a points dist. could be broken against the trans tunnel. You remove the engine mounts and jack the engine all the way up as far as it will go, jamming the transmission into the tunnel. I lifted the engine at the harmonic balancer using a wood protective fixture I carved out of a 4x4. Once the engine is all the way up, remove all the pan bolts and drop the pan. If the engine has a windage tray, remove it before removing the pan. That makes it easier. You will also need to drop the oil pump into the sump before working the pan out. You may need to turn the crankshaft so the front counterweights are at 12:00. That will give you a little more room as well to sneak the pan off. It's not an easy job. Most people prefer to remove the engine for a cleaner repair on a collector car.

[zippy]

Originally Posted by mgarblik

When I worked at the Pontiac dealer, I did allot of oil pan gasket replacements, in the chassis. Many under warranty. Pontiac's are leakers for sure. I would not attempt to do a pan with the car on the floor. You really need a lift so you can work the pan out and back in without ruining the new gasket, especially the rear rubber or cork seal. When I did them on a 2nd gen car, I unbolted the fan shroud so it was loose under the hood, removed the distributor as well. No way the pan is coming out with an HEI in there. Even a points dist. could be broken against the trans tunnel. You remove the engine mounts and jack the engine all the way up as far as it will go, jamming the transmission into the tunnel. I lifted the engine at the harmonic balancer using a wood protective fixture I carved out of a 4x4. Once the engine is all the way up, remove all the pan bolts and drop the pan. If the engine has a windage tray, remove it before removing the pan. That makes it easier. You will also need to drop the oil pump into the sump before working the pan out. You may need to turn the crankshaft so the front counterweights are at 12:00. That will give you a little more room as well to sneak the pan off. It's not an easy job. Most people prefer to remove the engine for a cleaner repair on a collector car.

Well crap. Lol. Now. Is it possible or advisable to pull crank while leaving pistons in block? Ie, leaving heads on etc. if I pull engine. To do pan. I might as well do rear main too. I have a re used BOP 2pc in there. But block has been line honed a few times. To the tune of needing a .010" shorter timing chain. If could be done without disturbing heads and valve train. Can one just remove mains and pull crank down enough to get a graphite rope seal in ?

[sdbob]

I made a c shaped box out of steel plate that I had about 3/16" thick. That slips over pan sump with starter in place rests on pan bolts it's a little longer than sump. Then I jack on that. Plate sizes it's what I had. Worked a few or many times. Yes I removed dizzy. Never did a rear seal replace in car.

[Sirrotica]

Take the engine out, if you try it in chassis you'll have a much higher chance of failure trying to do it upside down, rather than doing the work on an engine stand with the engine inverted. Plus it will drip oil on you for a week after you remove the pan, kinda like a form of torture.

Rear main in chassis, 99.9% chance it will leak, and the same odds you'll have to do it twice at least, ending up pulling the engine anyway. Pontiac shop manuals say it is possible to do the main seal in chassis, but I've never been successful doing it. I don't know anyone that has told me they did it successfully in chassis either. You really need the crank out of the block to at least have a fighting chance of having success.

If you decide to pull the engine, leave the transmission in the car. I have no idea why everyone pulls the 2 pieces out of the car together. Especially if you have limited space in a shop, leave the transmission in the car, tie it up to the cowl, and push the car outside. You don't need the transmission in your way while you're working on the engine, and you don't need a red sea of ATF (or gear lube if it's a stick car) all over the floor to clean up either.

I've tried this job multiple ways over half a century of wrenching, and the way I described it will give you the best possible odds at success. Work smart, take your time it's gonna be at least a weekend of 8 hours a day to complete. This is not a job to hurry, or try to shortcut. It's a miserable job no matter how many times you've done it, and disheartening if it leaks when you think you've fixed it.

[track73]

I did it twice. I just followed the instruction from either Motors Manual or Mitchell's.. But I had the advantage of a twin post lift. I didn't think it was that difficult either. One time it was to RR & broken piston and the other time was to replace a burned piston.

[mgarblik]

Originally Posted by zippy

Well crap. Lol. Now. Is it possible or advisable to pull crank while leaving pistons in block? Ie, leaving heads on etc. if I pull engine. To do pan. I might as well do rear main too. I have a re used BOP 2pc in there. But block has been line honed a few times. To the tune of needing a .010" shorter timing chain. If could be done without disturbing heads and valve train. Can one just remove mains and pull crank down enough to get a graphite rope seal in ?

Yes, it can be done. Your success rate would probably be pretty low. Once again, outside of a dealer environment, I would recommend removing the engine as Sirrotica explained. Once on the engine stand, and upside down, you can get everything really clean. You can also test fit and adjust the pan as needed. Your success rate will go up exponentially. As far as the "Best graphite seal". You need to remove all the main caps and pry the crankshaft up. You should be able to remove the seal pretty easy. Take your new seal and pack it tight in the cap and then cut it with a NEW single edge razor. Then very carefully remove it without changing it's packed shape. Transfer the shaped seal half to the block cavity being careful to center it end to end and not changing it's packed shape. Then fit the second half to the cap, pack and cut. Lower crank back in. Don't forget to apply anerobic sealer to the cap just where the seal parting line is. Not under the entire cap mating area. That will seal that leak point. Factory service manual shows this well. People often fail to do this and almost a guaranteed leak there. Many different opinions about the rear oil pan seal. Personally, I do not use a seal at the rear. I apply a thick bead of RTV carefully to a clean and dry surface and give it 8 hours to dry. Been doing them that way for 20 + years with good results. Seems cork is the second choice in this message board. Not many people have luck with the 3 or the 5 tab rubber seals. Most people know I can be a little cheap. But I recently tried the BOP one piece pan gasket for the first time. It worked well and did not leak. So I am 1 for 1 with that expensive gasket. Good luck with it.

[ErikW]

The guy I used to work for in the early eighties was an old school Pontiac dealership mechanic and had a fixture that bolted to the two ears on the timing cover and you raised the engine with a pole jack. Of course you had to use a lift and depending on application you would unbolt the shroud and possibly remove distributor as stated before but it can be done. Picture a U-shaped fixture constructed of angle iron with two tabs that bolted to the timing cover. I used it several times while working there for oil pan gasket and/or rear main service.

[John Milner]

I replaced a pan gasket and oil pump/rod on a 71 GTO a few years ago. I had to raise the engine up and I ended up having to remove the transmission, bellhousing and flywheel/clutch to get the oil pan out. I don't have a lift and was laying on my back to do the swap. It was far too much work and I should have pulled the engine. You can have an engine out of the car in nearly an hour. It will be much easier to do a better job with the engine on a stand.