Oil Drain Tube Help Needed

B

B.SUTTON

Junior Member
My 30 Tudor was missing the oil drain tube on the rear main, which I believe is the primary contributor to the large oil leaks out the bellhousing. Not only was the tube missing, but so was a small chunk of the main cap casting where the tube threads in. It appears that there should be a vertical tapped hole that the tube threads into, and also a horizontal hole that is the end of the oil galley in the cap. The broken piece of casting would be the piece between these two holes. I'm left with half of a tapped vertical hole and half of a smooth bore horizontal hole. Should the horizontal hole be plugged? If so, with what? It appers that the end of this hole is too close to the drain tube hole to be plugged with a galley plug. Does anyone have a picture of this area of a rear main cap? Any info would really help me patch this mess up. Thank you!
 
See if this is any help. Yes the horizontal hole is missing the plug.
 

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B.SUTTON said:
My 30 Tudor was missing the oil drain tube on the rear main, which I believe is the primary contributor to the large oil leaks out the bellhousing. Not only was the tube missing, but so was a small chunk of the main cap casting where the tube threads in. It appears that there should be a vertical tapped hole that the tube threads into, and also a horizontal hole that is the end of the oil galley in the cap. The broken piece of casting would be the piece between these two holes. I'm left with half of a tapped vertical hole and half of a smooth bore horizontal hole. Should the horizontal hole be plugged? If so, with what? It appers that the end of this hole is too close to the drain tube hole to be plugged with a galley plug. Does anyone have a picture of this area of a rear main cap? Any info would really help me patch this mess up. Thank you!
Click to expand...
the horizontal hole is plugged with a small flat plug called a welsh plug and is tapped into the hole to wedge in. The top hole is tapped for the tube to thread into. You might be able to thread the tube into it's respective hole and position the welsh plug in it's hole and secure it with JB weld. I would also spot weld the tube in an area directly adjacent to the broken area. I fix these all the time. I don't throw any cap away unless it is absolutely damaged beyond repair.
 
The horizontal hole was plugged with a small plug similar to a freeze plug. I found one in a Dorman drawer at a local auto store. You insert it and tap the center to expand it to fit snugly. In your case, you could spot weld the tube and plug in place with a mig welder, being careful not to heat the cap too much. Some JB weld in the remaining hole should plug the missing piece. Press it in to form a lock so it does not fall out, but be sure you do not block the oil flow with it. V the threaded back of the tube so it does not occlude the oil flow when it is screwed into what is left of the hole. I'll post a pic a bit later tonight.
 
Suggestion if you weld on the cap when it is removed from the car ... cover any exposed babbit nearby with a wet towel to prevent any welding sparks from being embedded in the babbit which will scratch the crank.
 
here is a photo of the plug end. If you go to all the trouble, be sure to use the larger tube. There were 2 sizes. every engine I have opened with a missing tube had an oil leak. This should solve most if not all your trouble

5565811163_0d67eefcfc_z.jpg
IMG_0980 by tiopato2000, on Flickr
 
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