1968 Eldorado 472 oil pan gasket and freeze plugs replacement - engine overhaul

[IcebearLars]

Hi there,

have on my 68 Eldorado my oil pan gasket leaking as well as two of the freeze plugs on the right hand of the engine block just below the headers and didn't find some useful tips regarding the replacement within my search here.

Oil pan gasket:
My 68 shop manual is telling me under chapter 6 note 127 that I have to remove the engine to replace the oil pan gasket (wow - that put me on "fully awake" this morning!!!) - here is what stated there:
"1. On 693 cars remove the engine as described in Note 140a and proceed with steps 9 and 10." 
"9. Remove nuts and cap screws that hold oil pan to cylinder block and lower oil pan."
"10. Remove side gaskets and rubber front and rear seals from oil pan, and discard."

It is obviously that with the right side of the final drive" on the car the oil pan can't be lowered since the axle is running direct below the pan - so for me the way with less effort to get the oil pan down and new gaskets on would be to remove "only" the right side axle.
Any suggestions to move forward without taking the engine out will be highly appreciated 

Freeze plugs:
Main question is to get the right size of them - Rockauto catalog is telling me different sizes of single available freeze plugs


1st question is now which one is the right one for the freeze plugs below the headers?
2nd question is should I order only the two I need or should I go with a full set and change all of them to be sure having only once the effort for the next several years?

Thanks in advance for your help

Lars

[Glen]

On the oil pan, take a closer look.  The frame cross member also runs under the oil pan.  It makes it impossible to get to the pan bolts.  I went through that years ago. 

[IcebearLars]

Hi Glen,

thanks for the heads up - will check this.
So what you are saying is that the shop manual is right and I can't avoid to take the engine out?

Regarding the freeze plugs I took a closer look on the ones installed in the Eldorado as well to the ones in my spare engine.

The Eldorado engine wears freeze plugs stamped with 1 49/64" (44,8469 mm)
The spare engine wears freeze plugs stamped with 1 3/4" (44,45 mm)

Since I prepare this replacement the clear suggestion was to use brass plugs - the available ones are
SEALED POWER 3819031 Brass Deep Cup Freeze Plug in 1.750" (44,45 mm)
DORMAN 565036 Brass Cup in 1.767" (44,88 mm)

Now I am puzzled which one I should use - any advise or am I overestimating the 4/10 mm difference of the two and it doesn't matter?

Thanks

Lars

[Scot Minesinger]

Yes, while there are some ways (not many) to perform repairs easier than shop manual this is not one of them, the engine needs to come out.  If engine is out, now is the time to replace the timing chain and rear main seal.  The oil leak is more likely due to a rear main seal than the gasket on oil pan.  The rear main seal costs about $20 and it is a 20 minutes job if you take your time with oil pan already off (make sure you do not install backwards).  The timing chain is easy with engine out and costs about $60 for the part, plus probably another $30 in gaskets/sealer. 

When engine is out then there are all the "might as wells" to do too; clean/repaint portions of engine bay, replace brake lines, fuel lines and etc. 

This is a nice winter project.

[IcebearLars]

Hey Scot,

thanks for clarifiication - yes - seems to be something for the winter 

What abou the freeze plugs - which ones to take?

Thanks

Lars

[Jeff Rosansky CLC #28373]

It's not the project, it's the "might as wells."
Good luck.
Jeff

[TJ Hopland]

Jeff is 100% correct on the might as well.   Hopefully you can get some driving in as is and see what else is wrong and how much you like the car.   If you like the car then its easier to spend the money doing it all right.    If it runs good just leaks a little here and there pull the engine and trans.   While its out you can do a nice clean up on the engine bay.   For the engine if you don't pull the heads that saves a bunch more might as wells.  Just getting the 'tin' covers off will get you a good look at the innards at which point you can either know you need a full rebuild or know everything looks good and some new seals, gaskets, and a timing set and you will be good.     Trans likely needs seals inside and out so good time to do those too.   Transmission is pretty much a THM400 so parts are not that expensive especially if its already out. 

As to which freeze plugs I would just go to a vendor like MTS 500cid.com.   They will have good quality stuff that will fit.    They also have a bunch of the little things you don't think of.   Things like a bolt and washer for the crank.  Its nice to have when you are trying to set timing and such.   Kit to eliminate smog pump?   Lots of goodies. 

[IcebearLars]

Hi guys,

thanks for your information - found the plugs & sizes in the engine parts illustration.

Need for the 472 are
6 of 1 3/4"
2 of 1 1/4"
1 of 2"

Have for sure more questions about the stuff I could replace or like you said the "might as wells" when the engine is out.

@TJ
Curious about the bolt and washer for the crank and the kit to eliminate the smog pump.
Can you tell me more about that?

Cheers

Lars

[TJ Hopland]

The 472-500-425-368 family of engine didn't come with a bolt in the front of the crank like most engines did,  the crank hub was just a press fit so from they factory these just came with a cork in em.   Its just a handy thing to have when you are doing things that require slight movements of the engine.   Its a slightly odd thread so usually not something you can get at a hardware store.

Most years of the engines came with a smog pump.  Presumably to make it difficult to remove they set up the belts so if you removed the smog pump you also lost the alternator and water pump.   The alternator ran off just the water pump.   They did this by changing the spacing at the crank pulley.   The smog cars the grooves on the crank pulley were all pretty close.   On the non smog cars they spaced out that front groove to align with the alternator so a belt would catch the water pump - crank - alternator.    70 was a non smog year.   I have also seen 75's and 78's.   If you can find one of those cars in a junkyard you can use the pulleys but that is easier said than done these days.   The additional twist in this puzzle is 68-74 the AC/PS was a dual belt.   74-79 they switched to a wider single groove setup to give more clearance for the larger cap HEI distributor.    You want to get things as a set, the crank pulley,  water pump pulley, and timing mark.   500cid makes and sells a kit that also includes a belt and plugs for the heads.   Its not super cheap but if you want to clean things up its an easy way to do it.   The pulleys are billet aluminum but have read they can be painted and then they look stock if that is your thing.


There will likely be lots of chunks of cam sprocket and valve guide seals in the oil pan and pickup tube.   Valve guide seals can be replaced without removing the heads.

[IcebearLars]

Hi TJ,

The 472-500-425-368 family of engine didn't come with a bolt in the front of the crank like most engines did,  the crank hub was just a press fit so from they factory these just came with a cork in em.   Its just a handy thing to have when you are doing things that require slight movements of the engine.   Its a slightly odd thread so usually not something you can get at a hardware store.

Is it this one http://www.500cid.com/_p/prd1/3520236441/product/crankshaft-bolt-kit?
9/16 SAE bolt 2" long?
Can't the little adjustments for timing be done with turning the flywheel?

Most years of the engines came with a smog pump.  Presumably to make it difficult to remove they set up the belts so if you removed the smog pump you also lost the alternator and water pump.

Will check on car - if there is all OK with the smog pump no action needed - correct?

There will likely be lots of chunks of cam sprocket and valve guide seals in the oil pan and pickup tube.   Valve guide seals can be replaced without removing the heads.

What do you mean by chunks of cam sprocket? Are there parts I could change or even have to change if I find chunks in there?

Bought already the timing chain, new FlowKooler Hi Flow water pump and a full engine gasket set (https://www.summitracing.com/dom/parts/fel-fs8255pt) which includes the valve stem seals as well as the rear main seal.

You mentioned if I don't pull the heads that saves a bunch more "might as wells" - what could be the mights pulling the heads or the other way around what parts should I include in my order when I plan to pull the heads - the head gaskets are in the set above?
Plan to buy as well this stainless engine hex bolt kit valve stem seals but it doesn't include the bolts for the heads.

The transmission is a TH425  - are there some full gasket set existing outside there including the mentioned inside and outside gaskets?

Your thoughts/advise is highly appreciated.

Thanks and sorry for all that questions - its the first engine overhaul for me - so I am pretty excited 

Cheers

Lars

[TJ Hopland]

Yes you can move the engine using methods like the flywheel its just less convenient than using the bolt up front.   I don't think I would special order just the bolt but if I was ordering other things from them I would throw one of those in with everything else. 

If your smog pump is working fine or you need it to pass inspections then all you need to do is make sure its in good working order.  What usually kills them is the check valve going bad and letting exhaust flow into the valve and pump.   The exhaust kills the bearings which then kills the pump which then breaks the belt leaving you with no water pump, fan, or alternator.   Pumps still seem to be available but the diverter valve is apparently pretty hard to find.  The check valve is somewhat universal so those should not be hard to find.   The valve on these engines is the nut looking fitting on the crossover tube between the heads that has the hose nipple on it.   To test it simply remove the hose and start the engine.    If you feel exhaust coming out the valve its shot.   You should also feel air coming out the hose end all times except deceleration.   It can be hard to test so the easiest way is just to get a hand vacuum pump and operate the valve that way.   High vacuum (like from closing the throttle) operates the valve which then diverts the air out a port on the valve assembly instead of into the heads.   If this does not work you tend to get popping in the exhaust and sometimes it can be significant.    IF you don't get air out the tube pump is shot so I would be concerned about the bearings.   

The original cam sprocket was covered in a plastic material that with age tended to crack and flake off and end up in the oil pan.  Not much seems to come out with oil changes, most of it seems to end up stuck in the screen of the oil pickup tube.   A part of the valve guide seals was similar material and ends up in the same place. 

One gasket that is not included in the full set is the intake gasket / valley pan.   Be sure to order one of those.     

Cloyes is the only brand of timing chain that still has a good reputation.  Lots of stories of other brands having issues with the crank sprocket shattering upon installation or shortly after.   

As far as I know Melling is the only company making new oil pumps.   Originals were aluminum so often need to be replaced.   For the longest time at least half of the Melling oil pumps had a rough spot in the casting that was not machined correctly and would cause the bypass valves to stick open causing complete loss of oil pressure.   I also had one where the idler gear sized.   Maybe they have corrected this now?   Maybe someone else makes them too?   To be safe you want to check and correct this issue yourself or buy from a vendor like 500 cid that checks and corrects this issue before they ship em.     There are 2 different pumps the difference is the angle of the oil filter.  The 472/500 one points it away from the crank the 425/368 angles to the crank.   

I bought a bolt kit and don't like it.  They don't stay tight.   They were regular looking bolts with regular flat washers.   I think what you want is more like the originals where the washer is sort of built into the bolt head. 

On the transmission what I mean by inside gaskets is things like the seals on pistons and servos.  If they are original there is no way they are working as good as they should or could be.   They won't be exerting as much pressure as they should be on the clutches and or bands which will mean there will be some slipping.  It may not be noticeable at first but slipping causes heat and wear which causes more heat and wear which is where a rebuild can get expensive.   The soft parts kit for this or any transmission is not very expensive, its when you damage hard parts that it can get expensive.    The trans and engine can come out separately but its a lot of work either way so you don't want to have to do it very many times.         

[IcebearLars]

Hi TJ,

glad that I made no miskate on the timing chain - odered this Cloyes https://www.summitracing.com/parts/CLO-9-1139.

Will check the smog pump - thanks a lot for the instructions

The intake gasket is now in the shopping cart 

Will watch out for the bolt kit - if I dont find anything can I reuse the original bolts tighten them along their specified torques?

Is this the right gasket kit you mentioned https://www.summitracing.com/parts/CLO-9-1139 - it includes no filter what I can see, but that can be ordered seperately.
Or should I go with the one including all rebuild parts like this http://www.oregonperformancetransmission.com/mm5/merchant.mvc?Screen=PROD&Product_Code=OPT-TH425-RB?

What about taking the heads off - is there something on top of the head gaskets which I should take in consideration?

Guess cour comment on taking the enigne & trans out seperately points to getting them out in one piece and taking them apart more relaxed outside the car - correct?

Thanks

Lars

[IcebearLars]

Any update here?

Thanks

Lars

[savemy67]

Hello Lars,

When removing any original bolts, use a torque wrench so that you can make note of the torque required to remove the bolts.  If the removal torque is close to the specified installation torque, it is likely that the bolts have not exceeded their yield point.  If the bolts show no signs of corrosion, deformation, or thread distortion, you should be able to reuse the original bolts.  Generally, if a flange-headed bolt was used, and it needs to be replaced, a flange-headed replacement bolt should be your first choice.  I don't think stainless steel bolts are any advantage in most engine rebuilds.  Be sure to clean the threaded holes before reinstalling any bolts and verify whether the bolts should be installed dry, with lubrication, or with sealer or anti-seize.

Christopher Winter

[IcebearLars]

Thanks - need now only some advise about the gasket kit and if the engine/trans/final drive should come as a whole or in separate out of the engine bay.
Think it would be easier to take them apart from each other when then are out of the car to overhaul them.

Cheers

Lars

[IcebearLars]

Hi folks,

putting my aged thread byk to live since I have started 2 days ago to get the engine and tranny pulled on my 68 Eldorado.

Getting everything out of the way I am still not sure if I can pull the engine/tranny assembly together at once or I have to go the route to first pull the engine and afterwards the tranny seperately.

Have already taken the power steering pump and the AC compressor out of the way as well as the disassembled the radiator fan, AIR pump and power generator.
Radiator is still in the car as well as the water pump.

Next action will be to get the drive axles disconnected and then I would be able to pull - but need advise here what to pull - engine&tranny at once or as seperate units in 2 pulls?

Thanks in advance for your help.

Cheers

Lars

[bcroe]

There is more than one way to skin a cat, but my
methods can be done by one person with minimal
risk of colateral damage. 

I take the car somewhere with a low ceiling,
raise the hood, and connect it at several points
to hanging chains.  Now move the car to the main
work area, support the final drive with a chain,
disconnect the trans from the engine (mostly from
below), and yank the engine.  At this point a
chain could easily yank the trans and final drive
after dis connecting shafts, or just leave them. 
good luck, Bruce Roe

[IcebearLars]

I guess supporting the final drive with a chain is similar to get a jack underneath and support it - right?
Does your method mean that getting the engine and the tranny in one piece out is not possible? 

[bcroe]

Pulling the whole thing works in the yard, but
that is a lot of weight swinging around, and the
chances of damaging something else in that close
area is high.  I am patient, careful, and do not
mind getting under the car.

I do not use jacks under the car, because then it
cannot be moved, and it is tough to get under it. 
Bruce Roe

[Daryl Chesterman]

I guess supporting the final drive with a chain is similar to get a jack underneath and support it - right?

Supporting the final drive with a chain is not the same as using a jack.  Remember that when you start lifting the engine, you are taking weight off of the suspension, so the car will rise as the weight of the engine is lifted.  If you try to support the final drive with a jack, as the weight of the engine is lifted, the jack will not be supporting anything since it's base is on the floor.

Daryl Chesterman