472 OIL PAN

[cadman56]

How many different oil pans were used on the 472 engines in the RWD cars?  Thanks, Larry

[Scot Minesinger]

Larry,

The most likely way someone to really know the answer for a certainty they would have to have worked on removing the oil pan on the 1968 thru 74 with some regularity, and that is going to be difficult to know.  Part numbers are not always right as an authority on this question.  Why do you ask?  Maybe we can help that way. 

I would think that they would be all the same, but that is a guess.

[cadman56]

Scot
This is about a 73 472 engine,
I am asking because I purchased a new oil pick up tube from the CAD500 parts people in New Mexico & the oil pan will not set down on the block, the tube is interfering with the pan.  Cad500parts people said they test fit the second one they sent me & it was just fine but the bolt holes still do not line up well enough for all the pan bolts to fit.
I guess I will try to massage the pan to get it to fit on, that is what the vendor said to do.
Believe me, I am not happy about this.
Larry

["Cadillac Kid" Greg Surfas 15364]

Larry,
First of all there is one pan gasket used for ALL 472/500/425 motors, so that means the pan bolts are ALL identical. Are you getting a stock replacement pan or are you buying Cad Co's "custom" pan?
Secondly are you installing the pick up tube and the pan while the motor is in the car?  If so it is difficult to get everything lined up.
What part of the pick-up tube hit the pan and IF you (gently anhd carefully)  bent the tab where it bolted to the main bearing, would it move enough to clear?
Greg Surfas

[TJ Hopland]

There were basically 3 factory pans that fit the 472/500/425/368 family of engines.   They are most commonly known as  'front sump', 'mid sump' and 'rear sump'.     

The front sump was used on the RWD cars 68-76 and is basically backwards from what you would expect a typical GM oil pan to look like from the era.   The mid sump was used on the RWD cars 77-79 for sure and possibly 80- till the end of the 368/6.0.   This looked more normal but the main sump part was not quite all the way to the back like say a Chev pan.   The rear sump was used on the Eldorado 68-78 then possibly 80-81.   This was a pretty odd looking pan.  It had a small shallow sump area up front with its own drain plug then a hump (where the right drive shaft went through) then a low deeper than usual almost square sump area at the very back with its own drain plug too.   

Each pan has is own pickup tube.   68-69 was one block casting then 70-76 was another.   Basically they were the same but there were slight differences among them was the diameter of the oil pickup hole and tube.

Sitting here 40 years later its hard to tell what has maybe been swapped.   I don't know if the mid pan could fit in a 73 or not.  I would guess not or they would not have come up with that front sump design.  The 425 blocks I think used the same pickup as the later 472/500 blocks so it would still be a matter of matching the pans.

Here is a comparison photo that may help you figure out which parts you may have.

Back of engine is bottom of photo, front Top.
The left pan is a customized rear/eldo pan.   The second from the left is the stock rear/eldo. 
Middle pan is the mid sump.  Middle right is the front sump that would have been on a 73 and the right I think is a small block Chev.   

["Cadillac Kid" Greg Surfas 15364]

TJ,
The difference in pan shapes was to clear the chassis.  They ALL will fit the 472/500/425 blocks.  The answer is yes, I used the 425 pan on my 500 in my '79 Paris (el camino style conversion) that originally had a 425.  Larry's issue is the poan not fitting his block.  Something is wrong with the pan or as I said before, if the pick-up tab is bent it might cause interference with the pan or rotating parts.
Greg Surfas

[TJ Hopland]

They way I am reading his post is that he was just trying to replace the pickup tube and is dealing with the same pan that was on the engine when he started.   Am I reading this wrong?     

That does raise the question why would one need to replace the tube in the first place and how does the 'new' tube compare to the 'old' one?

My reason for posting the pics of the pans is that maybe its possible to use the 'mid' pan in a 73 and that is what he has but he is trying to fit a front pickup in it?   I was thinking maybe if he saw the photos of all the pan options he could then look at where his issue was and maybe be able to figure out that he had the wrong one.    Its been too long since I worked on a pre 76 RWD I don't remember what it looks like underneath so maybe its not even possible.     Maybe he has the correct front sump and cadco keeps sending mids?

[cadman56]

Dear all,

I replaced the original pick up tube because I could not get it totally clean.  I got the replacement from CAD500part.com in New Mexico.  Their replacement tube stands about 3/8" taller than the original.

What I did this morning was install the old pick up tube & mark the block with a fine line welder's chalk stick to get a flange profile.  I then repeated the process with the replacement tube.  The bolting flange of the replacement tube is wider so I carefully ground it to match the original's profile.  Then I spray painted the inside of the oil pan with black paint to find the location of interference, I located it  then carefully massaged the oil pan with my 3 lb. ball peen hammer to create clearance.

All is now well, but I DON'T like doing things this way.  Hope this clears up the confusion.

Regards,  Larry

[TJ Hopland]

Was this a new / reproduction tube?   Or a used / old stock?   You would not really expect that much difference in an original parts especially considering the apparently close clearance with the pan.   

Tube diameter was the same in both cases?   If it was that would seem to eliminate the possibility that it was a 68-69 vs 70-76 sort of a difference. 

[cadman56]

Sorry, I'll get it correct some day.  I purchased a new reproduction tube which had a diameter of 3/4".  I am using the original RWD oil pan & it and the engine is a 1973 472.  Larry

[TJ Hopland]

Interesting that cad co (or anyone) is reproducing a pickup tube for that style.   Most of the people looking for a replacement I would think would be looking for something other than that style usually for swaps into other vehicles.   It really stinks when someone goes through the effort to reproduce something and does not quite get it right.   I'm not blaming cadco here because I have no idea if they made it or had it made or if they are just a reseller.  I thought cadco had got better but maybe not, earlier they definitely had the reputation for parts that didn't quite fit.


Yours was crammed full of timing gear and valve guide seal bits I presume?    I remember hearing there were a couple different styles.  Some did clean easy and others didn't.  Same with taking them apart some have reported being able to take them apart for cleaning and being able to go back and others have not.   The ones I have done I had to smack around quite a bit but I was satisfied that I had got most of it out.     

[Scot Minesinger]

Live and learn, next time I would try and buy a used pick up tube or invest more effort in restoring the original.  I agree, changing the shape of the pan with a hammer is never the best way, but sometimes there is less of a choice. 

[chrisntam]

When Marty (MTS) built my motor in '14, he re-used my old pick up tube (after cleaning it), he said replacements weren't available.

After I put the motor in the car, while priming the engine and getting it lubed up, a small piece of hard nylon (either part of the old timing gear or valve seal) got sucked into the oil pump and stopped it cold.

Had to pull the pump and clean out the debris.  Pissed me off, after spending the money I spent on the motor, that should not have happened.  He said (at the time) they are difficult to get clean.   True??  I have no idea.  He did send me an oil pump gasket though, that I have yet to install and I still have an oil leak that I haven't repaired yet (I had to reuse the existing pump gasket).  grrrr.

So you can choose, I guess, which issue you want to deal with. 

Rant on.  Still dealing with my issue.  Haven't made the time to pull the pump off, put the new gasket on, pull the dizzy, prime it, put the dizzy back in, reset the timing and get it started.   The snout on the water pump only gives a 1/4" of clearance between it & the pump.  I'll have to pull the hose to get the pump installed.   Rant off.

I suppose if it was easy, everyone could do it.......

ymmv.

chris.

[Scot Minesinger]

Chris,

I always thought that the oil went thru the filter first and then the pump, but I guess your experience is that the oil flows thru pump first, then filter.  Good thing this happened when you were priming, as if it happened when car was running a major failure, such as distributor shaft, oil pump shaft gear on distributor or something would have failed and been a significant repair.

Also I thought MTS ran their engine rebuild jobs before sending them out, or is that an optional service?

Know what you mean, after 11 years of my engine rebuild the rear main seal is leaking, so will have to drop the pan to repair it.  Fortunately the car has dual exhausts and will not have to do any exhaust work to make the repair.  Probably will be getting to that this month. 

Had to do a similar repair on my trans that was rebuilt 11 years ago.  This past month had to replace the electrical connector O-ring (drop trans pan), rear drive shaft seal (twice, first one did not hold), and the internal O-ring where tail of trans comes off and the one on trans power shaft with splines is replaced. 

These newer rubber seals in rear main and trans just do not hold up I guess.

[TJ Hopland]

The Cadillac the oil pump drive shaft goes before anything else gets serious damage when the oil pump comes to a stop.  I know this first hand on the 500.    I didn't buy my first pump from MTS when I rebuilt mine.   My second pump and second set of bearings did come from MTS and those are still working.

I can't think of an engine I have tangled with off the top of my head that the oil filter is pre pump.

[cadman56]

They very reason I ordered the new pick up tube is what Chris mentioned happened to him.

I have rebuilt many engines of many different makes in my life, I worked very diligently on trying to get my original pick up tube cleaned but was still unsure, so I ordered the new one.  The short block is now fully assembled.

The oil filters are down stream of the oil pump of every engine I have rebuilt except for the canister filters of the 55 & 56's.  My buddy has a 57 & I believe it is also a canister filter.  I am not familiar enough with the earlier years to comment on.
Larry