I recently had to replace the expansion plugs/freeze plugs/block plugs/casting plugs on my 7.3 IDI (there are many names to call this part). Unfortunately if you are in the same shoes as me you would know OTC doesn't have any stock of the factory tool style tool OTC 303-D045. I searched the forums to find a drawing of the tool to have a machine shop make me one as many have done before me, although locally this would have cost around 280 dollars based on the quotes I got (your mileage many vary). After receiving such a quote I decided to try and quote multiple online CNC machine services to see what it would cost to have the tool made as a one off unit. To do this required a 3D CAD file which was not too difficult for me since I have a background working in CAD design. The cheapest quote I got was around ~$88 for each part of the tool made out of 4130 steel, this price was from https://www.rapiddirect.com/ after uploading the 2D technical drawing(added tolerances to measurements) and the 3D CAD files with an 8 day lead time and 50 dollar express shipping. One thing to watch out for is tolerances, based on all the sites I quoted the tolerances vary greatly which is why I specified +\- 0.001" for the measurements on my tool in a 2D drawing. For a total of 226 dollars I was able to get the tool shipped to my front door and the final product was excellent very dimension was within 0.001" as I requested. Send me a private message with your email if you want the CAD files for a CNC service, or the technical drawing to have a machine shop make the tool for you. (Gandalf on Oilburners provided me the technical drawing, but its been floating around a long time on many different forum sites).


After receiving the tool I immediately put it to use to install the welch style plugs into my block. Here are the steps I followed, I couldn't get factory welch plugs so I purchased these https://www.dieselpartscenter.com/we...-pai-3482.html (Pai 3482) they seemed to fit well and come in packs of 5. I DON'T recommend using the brass style as they are just too soft to grab the block properly, note that I'm replacing brass plugs in my picture.

Step 1: Remove the old expansion plug, I did this by drilling through half the thickness then hammering the plug with a air hammer bit.

Step 2: Clean the the bore out, I used a brass wire wheel on a drill that was 1.5" in diameter. I also used a small flat head screw driver to clean the bore, and brake clean.

Step 3: Coat the bore lip area with sealant of your choice, I used Hylomar M but you could use Permatex aviation cement. Use RTV if the bore has significant scaring.

Step 4: Coat the plug with sealant and place flush at the top of the bore.

Step 5: Use the radius cut part of the plug seating tool to 'lightly' hammer the plug to the bottom of the bore till it stops on the lip seen in step 2. The radius cut is made to match to contour of the plug so it doesn't expand the plug out while pressing into the bore.

Step 6: Plug seated in bore.

Step 7: Hold the plug seater on the plug and slip in the punch section. Notice the gap between the head of the punch and the plug seater.

Step 8: Hit the punch till the is no gap remaining between the two sections. This will dent the plug forcing the sides to expand and grab the block casting holding it in place.

Step 9: Seated and dented plug.

I hope someone finds this helpful, and if there are any tip or comments please post below.

 

I would be interested in the drawing and 3D cad file for this tool.

 

Hi,
I’m currently in the process of replacing the Welch Plugs in my 7.3 idi motor.
Any chance you could please email the CAD Drawings for Plug Installation Tool to: info@eternitymotorco.com.au
Thx
I really appreciate it - Thx
- Leith

 

Excellent!

I would have just used a punch to remove the old freeze plug and a socket and extension to install the new one.

Here's a good threads on OBs about installing freeze plugs. I guess if I could find that OTC tool it would be a good investment. Don't forget, he who dies with the most tools wins.

https://www.oilburners.net/threads/f...ug-tool.20195/

 

I’m in need of this tool as well, if I could somehow get ahold of those CAD files that would be great. I tried to PM the OP but this site said I don’t have permission to do so (probably because I registered this account just now in hopes of getting the info for the tool).

I have the 2D drawing that has been floating around these for forums for awhile, but my local machinists aren’t interested; they say it’d be a waste of time for them.

 

Do you have a email you could provide me here?

 

Yes sir, thank you for replying! I didn’t want to post the email publicly if it wasn’t going to do me any good: deusvult5687@gmail.com