changing the pan gasket how hard

[cjoenny89]

My pan gasket is leaking bad in my 68. It has a 327. I am assuming it is the pan. The engine sat for 25 to 30 years with the occasional start up after being rebuilt waiting for me to get old enough to get the truck from my dad and finish it up.
Anyway It appears the Pan gasket is leaking around the hump in the front under the harmonic balancer.
With it being 2-wheel drive is it even possible to change the pan gasket in the truck with it being so close to the front cross member?
Is there enough room?
I know it has the 4 piece cork gasket on it and it appears to be off center like the gasket slipped. I bought a 1 piece gasket for it.
How hard is it going to be to change the gasket?
Thanks

[custom10nut]

It's possible, and not hard, but can be frustrating. If you have access to a lift it'll make the job a lot easier.

[AussieinNC]

Not that hard to perform with engine in place, however, it can be frustrating...

Suggest you yank the engine and put it on a stand...replace the pan gasket with a one piece rubber one...reverse dimpling the bolt hole flange area...then using silicone sealer on both surfaces. The gasket push out is usually caused by the bolt hole area being dimpled up from over tightening the pan bolts.

While its out, replace the front timing cover seal, and lift off the manifold and replace that gasket as well...use the usual paper type along the port surfaces, but use a good thick run of heavy silicone on each manifold end run.

Then replace the rocker cover gaskets, again, reverse dimpling the bolt holes...use the rubber style rocker cover gaskets.

Finally, replace the oil pressure switch...then re-install the engine with new mounts...

Sounds like a lot, but, doing it all while it is out will save you lots of heartache later...

have fun

[hewittca]

Everything AussieinNC suggested is great advice if you are willing to go that far and take the motor out. Here's a word of caution though, I just performed a "simple" pan gasket replacement on my '68 and it turned into a can of worms quick! Getting the pan off is frustrating but easy enough, just make sure your crank is turned 180 degrees from TDC for the most clearance up front to get the pan out. Even then, some people end up needing to unbolt the motor mounts and hoist the engine up a few inches to get the pan to clear the oil pickup. I had my trans out doing a repair on that and was able to jack the back of the motor up which made getting the pan out easier. Now to the fun part. I discovered that my oil pickup was filled with nylon teeth from my timing gear. GM used a nylon coated timing gear on the cam, so I would inspect your pan and pickup to make sure yours hasn't come apart. Even if it hasn't, it might be best to go ahead and replace that too. All in on just a pan gasket replacement, I ended up replacing the rear main seal, oil pump, and timing gear set as well.

[toiletbowl54]

I have done the oil pan gasket on my 71 350 and a 1990 5.0 mustang. The way I did it was to place a piece of 3/4" plywood under the oil pan then used a jack to put some tension on the oil pan. You then remove the bolts on the motor mounts, jack the engine up so you can slide a small piece of 2x4 between the motor mount halves then lower the motor onto the 2x4's. This should give you enough room to drop the oil pan with out removing the oil pump. The mustang was the hardest because it had two sumps. At least that is the way I did it.

[cjoenny89]

all great ideas!
The engine has been rebuilt for 23 years but has only came to life in 2013 and has less then 500 miles on it. We are still breaking it in.
The engine was rebuilt in 1989/1990 and started off and on over the years as it sat in the truck as it waited for body work. I got the truck fired up and working on it in 2013 running it constantly in 2013 till now. I bet we have less then 500 miles on the engine. I know it is finally breaking in because it starts easier and easier all the time. I am sure the pan seal dried up and is off center and it is possible the front and main seal is leaking as well.
I may pull the tranny to replace the clutch since My dad didn't do that back in 1990 and it still has the original 1968 clutch with 47,750 miles on it.
I just got done replacing the drive shaft u-joints and carrier bearing and that took most of my shake away and I think the rest might be the clutch.
Since engine mounts were mentioned I may check those maybe I have a bad one causing some jumping around.
as far as other engine problems I doubt I have them since the engine has so few miles on it.
Thanks for all the suggestions!

[mike16]

removing the gasket is pretty much routine. If you get two short lengths of two by four's and place them between the motor mounts and the engine block that will get the engine high enough and away from the frame to pull the pan down and away from the engine. You may have to lift it a bit further but the blocks of wood should get you there


dont get in a hurry and strip out those small oil pan bolts

be carefull lifting the motor. I dont recommend you lift it using a jack on the harmonic balancer. it may damage the outer ring or cause it to separate from the hub ring and if it comes apart when the engine is running it will take out everything in front of the engine

if your going to pull the pan, I recommend you pull the timing chain cover too and put a new timing chain and gear set up on the engine. it only takes a little bit longer and concludes a thorough job. The reason I suggest this is because I went to install a new pan gasket and found out after it was all apart that it was that front seal, either way you MUST pull the pan to replace the front timing chain cover gasket.

that having been said, when you go to install the timing chain cover with its new crank seal, install the cover but DONT tighten it up to the block, install it, but leave it loose and install the harmonic ballancer, do it this way to ensure the seal is centered around the sealing surface of the harmonic ballancer hub evenly befor you tighten up the timing chain cover. otherwise it may leak emeadiatly or shortly after if the hub is not centered evenly inside the seal. If your harmonic ballancer has a worn groove from seal wear, replace it. speedy sleeves are a band aid fix, replace the old ballancer.

when installing the hardware, take the time to do it properly because in the tight clearances it can get easy to stripp out or cross thread the bolts holes. and that will really mess things up.

also might be a good time to put a new oil pump on there. Higher volume yes but try to avoid high pressure pumps as they can force changes on your timing through a worn timing chain or they can wear out the distributor gear as well.

take your time and do a thorough job, use lots of good quality type RTV sealer.

[mike16]

and some more images

Hope it all helps

best of luck and take your time.

[cjoenny89]

thanks

[67ChevyRedneck]

As you mentioned, I'd be concerned with the rear main and balancer seals leaking as well.

I bought a 65 Mustang that had a rebuilt engine, but was driven very little over a 10 year period. Motor ran great but leaked everywhere. Over time I replaced every seal on the motor (including rear main), I wish I had just pulled the motor and done it all at once.

[leftybass209]

If you're absolutely sure it's just the pan seal, it is doable without lifting the engine. Mine is a 350 auto in the front position. I drained it, dropped the pan as far as possible (doesn't come all the way out), scraped the old seals clean, and installed a 1-piece pan gasket just working it down inside the pan under the crank and back up the other side. Took about 45 min from drain to start-up.

I wouldn't want to do it again as it was uncomfortable, but completely possible.

[Marine-58]

It is always uncomfortable for me to tell someone what they "should" do. So what I would do, especially if replacing the clutch is to pull the engine. Not like we have all the computer crap to deal with on these things. (assuming that option is available). Aussie was spot on that it is better to just do it all and not have to worry about it. And the added benefit of not having to wrestle with the tranny while up under the truck. Just my $0.02 worth...

[AussieinNC]

I know the engine was rebuilt some 20 plus years ago, and your repair process will be your choice...

My suggestion would be to, along with my previous post, also check out the rear main wick style oil seal...remove the oil pump and the rear main bearing cap...

I can almost guarantee the wick style oil seal has shrunk back and will leak in the future. These old rag style wick seals were replaced in 86 when Chevrolet went to a one piece seal design, along with center bolt style rocker covers...

As it is now 2017, the 23 years ago rebuild could be part of the reason the cork style pan gaskets pushed out...

Anyways...just trying to give you my perspective on things...

Dont forget to reverse dimple to pan rail where the bolts come thru...Why ?

Put a ruler along the oil pan sump rail and see the high points around each bolt hole...that dimple acts as a punch and pushes the cork out of the way...often breaking the gasket...One piece neoprene rubber gasket, plus flatten out the rail area...

Way to go...and have fun

[mike16]

I pretty much agree except I would not pull any main caps. My truck had 71K on it when I did this and I went by the book on resealling the oil pan but got very generous with the rtv, I bough a huge tube of it that goes in a caulking gun and used quite a bit but once it hardened up I trimmed away the ooze with a razor blade. in six years it has not leaked but I made that mistake with the front timing cover seal. it does not leak but on a hot day and a long hual it weaps.

I tried to get the oil pan off with the engine mounted up but could not get the clarance,they were new motor mounts No way I'm going to clean gasket material unless I know there is none inthe oil an when it goes back together.

I did not know about the one piece oil pan gasket when I went shopping so I went old school, it worked.