‘75 Eldorado “might as wells” for oil pan gasket

[benji808]

Scheduled to take the Eldorado in for oil pan gasket...don't have a hoist and don't want to attempt the engine lift in my driveway right now anyway.

Anything that's materially easier to have the shop do while the engine is lifted? Not looking to add a lot of time and cost but if there are any simple add ons...

Thanks for any ideas!

[Scot Minesinger]

If your Cadillac is dropping oil, might be rear main seal leak.  Is the engine being removed from the car just to replace the oil pan gasket?

[V63]

Would be prudent to do timing chain and gears because the hardest part of that job is lowering the oil pan.

[benji808]

Good thoughts...the goal is "stop the oil leak"...I'm guessing it's the pan gasket but don't have a lift to get underneath it and really clean it and check, so I'll plan to have them try to confirm before pulling the engine.

Reading through the shop manual...looks like if we're pulling the engine then oil pan gasket, RMS, and timing chain all make sense to do...front wheel drive fun!!

[V63]

If the timing cover has been removed before...without lowering oil pan ..Very good probability for your leak at the oil pan front seal. 

[The Tassie Devil(le)]

Benjamin,

If you have to take the engine out to replace the sump gasket, then, I would also advise pulling the unit with the transmission as a unit, then checking the Transmission Drive Chain gasket as well as the Diff Gasket, and the Timing Cover Gasket as well as the Timing Chain whilst you are at it.

The Transmission Sump Gasket can be changed with the unit in place, but the drive chain cover gasket cannot.

If you cannot get a replacement Gasket for that cover, then do what I did and use some Loctite 5900, as that stuff is compatible with Auto Transmission Fluid.

Bruce.

[TJ Hopland]

Yup timing chain and don't forget to carefully clean and inspect the oil pickup tube for bits of cam sprocket. 

Whenever I have a timing cover off one of these I weld some 1/4-20 nuts to the inside back of the cover for the water pump.   Those bottom 2 bolts only thread into the 'tin' cover and are more often then not damaged from over tightening so you end up with both external and internal coolant leaks.    There is a ton of clearance in there and you can't see em unless you remove the timing cover so the weld job doesn't have to be neat, just has to hold.   If the threads are not already damaged thread some spare bolts in then spin the nuts down to align them to the existing threads and hold the nuts while welding.

Maybe replace the frost plugs?

Careful inspection of the flex plate for cracks?

Shift shaft seal is a common leak spot on these and can't easily be done with the trans in the car. 

[The Tassie Devil(le)]

I also agree with the replacing of the Freeze Plugs, but replace them with Brass ones.   Then they will never leak again.

And the welding of the timing cover nuts.   Some people never use a Torque Wrench when replacing a Water Pump, and those tin threads are very easy to strip.

But sorry TJ, the Shift Shaft seal is easily replaceable in the Eldorado, but not the RWD vehicles.   That is one thing that Cadillac engineers thought about.

Bruce.

[TJ Hopland]

Don't forget they made some changes to the frame and mounting for 73.  Maybe in a 72 its easy but in a 73+ it hits the frame before the shaft comes all the way out of the transmission.  You can loosen stuff and by a combination of removing a mount and jacking on the other side get just enough angle to force it out.