1928 Chrysler Model 72, Oil Leaking from Weep Hole at Rear of Engine

[leomara]

Oil is coming out of the weep hole and I cannot tell if it is motor oil or transmission oil.  What type of seal did the 1928 Chrysler 6 cylinder engines have at the back end of the crankshaft and what type of seals were at the front end of the transmission main shaft?

[trini]

What is a weep hole ?  Are you talking about a breather ? A picture ,if possible will help.

[leomara]

My 1928 Model 72 engine is out of my car and at the rebuilders so I cannot reference this, I believe a friend was talking about the hole at the bottom of the flywheel housing which allows oil to drip out as needed.

[stakeside]

My 29 DodgeBros DA6 engine may be similar. There is a reservoir at rear of engine. It has a slinger that slings oil at rear of engine. Excess oil should drain to the oil pan thru a tube. Excess oil will drain out. There’s no seal at the back of the reservoir .

These engines are notorious for dipping oil. Even my rebuilt engine dips oil.

I found possible causes to be: excessive oil pressure, improper installation of rear oil pan seal, and worn rear main bearing.

I ran an engine in my truck with unknown history, but it did run. The rear bearing was so badly worn that the oil  over flowed and poured out of rear of engine thru hole in bell housing.

[trini]

From 29 and up the engines on DB's are mostly continentals. My experience with these engines is there are several types of rear seals Some seals are a piece of fiber like asbestos rope , with one half in a grove in the oil pan and the other half in a grove in the block. It comes in 2 pieces. Sometime it is possible to renew the seals in frame. There is enough space between the tranny and engine . To do that it is necessary to remove the oil pan. push one half of the seal into the block and the other half into the oil pan grove. You may have to loosen the main caps a little and pull down the crank a little so as to remove and install the portion on the block. Press the  seal down hard with a wooden hammer handle to pack it tightly , Use a sharp razor blade and trim the ends of the  seal about 5 to 6 thou above the metal grove and install.The extra is called "crush" Tighten. After some miles you may have to re tighten. The hole in the clutch housing is primarily to let the engine oil fall to floor, if not the chamber can be filled with oil and get in the clutch plate. Some engines do carry oil slingers but they wear after some miles. 

[Vintageben]

Not sure if the 72’s were the same as the 75’s but mechanically I don’t think there was much difference. Here’s a couple of pages out of my 75 manual that may help. There is no rear main seal, the first thing I would check is that the drain passage isn’t block any way it is a bit late here so I will leave you with diagrams to study Cheers Ben

[hwellens]

On 10/31/2021 at 4:03 PM, leomara said:

What type of seal did the 1928 Chrysler 6 cylinder engines have at the back end of the crankshaft

There was a crankshaft seal, see below:

 

[Vintageben]

18 hours ago, hwellens said:

There was a crankshaft seal, see below:

 

🤔 hmmm interesting information, I will be pulling one of these engines down hopefully early next year I will be curious to see what I find as the manual doesn’t mention a seal anywhere. Anyway will be interesting to see if any others have experience with these engines.

[stakeside]

On 11/2/2021 at 3:01 AM, Vintageben said:

Not sure if the 72’s were the same as the 75’s but mechanically I don’t think there was much difference. Here’s a couple of pages out of my 75 manual that may help. There is no rear main seal, the first thing I would check is that the drain passage isn’t block any way it is a bit late here so I will leave you with diagrams to study Cheers Ben

 

 

 

 

Per attached pic item number 15 is rear main bearing oil passage. The rear main drains into this sump and If the bearing flow is to much to drain into the pan the sump overflows to bell housing area and drips thru hole.

 

 

 

 

 

 

Edited November 3, 2021 by stakeside
E (see edit history)

[trini]

I never worked on Chrysler engines like this. I know  in the 29 DB the engine is Continental.  Or at least some of them.There may be some made by  Chrysler too. I do not know. There are bloggers on this site who may know for sure and will be able to assist you. The main point is engines of any type do have some sort of seal at the back of the main bearing. I have seen oil slingers in that area, and some bearings designed in such a way, allowing the oil to pass the bearing in special groves to allow the oil to flow back into the sump At this point I suggest you check the oil pressure and compare it with specs if you can find it. In my Dodge Senior six the oil pressure after starting is constant 40 lbs regardless of RPM. Worn bearings, rod, main or cam will cause oil pressure to drop,It appears to me the rear main is specially designed as a combination of bearing and seal slinger . Bearings in those days were poured babbit and who knows what. I am hoping you are not looking down the road to a rebuild.   

[stakeside]

On 11/3/2021 at 1:27 PM, trini said:

I never worked on Chrysler engines like this. I know  in the 29 DB the engine is Continental.  Or at least some of them.There may be some made by  Chrysler too. I do not know. There are bloggers on this site who may know for sure and will be able to assist you. The main point is engines of any type do have some sort of seal at the back of the main bearing. I have seen oil slingers in that area, and some bearings designed in such a way, allowing the oil to pass the bearing in special groves to allow the oil to flow back into the sump At this point I suggest you check the oil pressure and compare it with specs if you can find it. In my Dodge Senior six the oil pressure after starting is constant 40 lbs regardless of RPM. Worn bearings, rod, main or cam will cause oil pressure to drop,It appears to me the rear main is specially designed as a combination of bearing and seal slinger . Bearings in those days were poured babbit and who knows what. I am hoping you are not looking down the road to a rebuild.   

Note following reference for Senior six but only used in some cars and 29-30 trucks. Smaller wheel base trucks used the DA-6 and were built by Dodge Bros.

the most notable different was the length of water jacket.

[trini]

stakeside, I was thinking along the same  line. It happens with all manufactures. They try to use all parts in the bins of the the previous models if they fit the new models. After the take over of the Dodge Brothers by Chrysler it is quite possible there were  left over of major components and Chrysler decided to use them until there were no more.

[trini]

Istakeside, I was thinking along the same  line. It happens with all manufactures. They try to use all parts in the bins of the the previous models if they fit the new models. After the take over of the Dodge Brothers by Chrysler it is quite possible there were  left over of major components and Chrysler decided to use them until there were no more. I know of a fellow who has a junk 29 car . He made into a hot rod. The engine is a continental 6. He has the cluster instruments for sale. wants 100 hundred dollars C. The engine is also for sale but will definately needs rebuild.