Technical 1937 Plymouth rear main question

So I dumped a bunch of gas into the block to let it sit and break up the slop in the pan and all that. And she just started pouring out the rear main. Wasn’t surprised. (Gonna take pan off and pickup tube off and clean it real good before I even start this thing)
Anywho. Is it possible to replace that split seal without separating the motor and trans?? Judging by the seal and design I was hoping maybe a guy could get away with it? Wondering if anyone has tried ?

 

Not sure but this video may help.

 

If you have the split rubber seal those are generally easier than the rope type seals.... I have replaced the rope type by tying a copper wire in the end of the seal and pull it in while rotating the crank.... Not easy but can be done... Years back they had a tool called Chinese finger lock they would use to pull in rope seals...

 

I was hoping to install one of these https://bestgasket.com/wp-content/uploads/cache/2019/02/4164/2961878880.png
But if I can’t I’m gonna try to do what you suggested

 

There were at least 3 different seals used in the Mopar flathead over the years. I don't know which is in your engine. They don't seem to be of a specific type by year of manufacture, one has to look as they could be dealing with a swapped engine or one that has been modded. The seal you picture was commonly use over several years and is easy enough to change. EXCEPT for those pesky bolts and just used on the flywheel to crank. The flywheel has to come off to swap the seal. I think the lower half may be able to be swapped without that, but not the top.

 

Dangit. That was what I was worried about

 

Good luck with that. The rope seal on my motor was cooked hard. I had to drop the crank down far enough so I could pop the top of the seal out with a hook tool. Installing another top rope seal wasn't fun either.

My 54 Dodge truck factory service manual suggests that you not change the upper rope seal with the motor in the vehicle. They used a special tool to "dimple" the old upper 1/2 of the rope seal on the one side (I don't have the manual here, and don't remember which side was dimpled). Then you set the new lower seal in the main cap with the seal offset to fill the dimple in the upper seal, seat the lower seal (with the special tool), then trim the excess off the non-dimpled side flush with the main cap edge. Then install the main cap & torque, then reassemble as needed.

 

@Jim Lato The first two or three characters on the machined pad circled in white in the photo can help identify what engine you actually have. It may not be the original engine. This can help narrow down which rear main seal you need by looking up the info in that year's shop manual.

 

My old Motors manual sez the flywheel must come off.

 

Dude thank you for this MEGA helpful info. I picked up this car this winter and yet to know what power plant is in it. This weekend I’ll go out there and find out. Maybe I can get this dang thing running soon