Mystery grease fitting problem

TomC750

TomC750

Senior Member
My '41 Mercury was missing the grease fittings on both the front and rear springs. They are of an odd thread size. I bought new ones from Third Gen Auto. They included new extender nuts which I did not need as the old ones were present. Now comes the problem - Because the extender nuts (both old and new) have slots on the threaded id, the grease extrudes through this path as I would expect it to do being that there is no way the grease fitting will seal against the extender nut. What am I missing here?
 
TomC750 said:
My '41 Mercury was missing the grease fittings on both the front and rear springs. They are of an odd thread size. I bought new ones from Third Gen Auto. They included new extender nuts which I did not need as the old ones were present. Now comes the problem - Because the extender nuts (both old and new) have slots on the threaded id, the grease extrudes through this path as I would expect it to do being that there is no way the grease fitting will seal against the extender nut. What am I missing here?
Click to expand...

The fitting has a tapered thread; thus, you are not missing anything. If the fitting is proper and was not cross threaded, the should be no leakage.
By the way, grease is not used in this place. You won't be able to find proper lubricant anymore. When I had finally used up my bucket (OEM) of leaf spring lubricant, I switched over to STP oil treatment.
 
Kube said:
The fitting has a tapered thread; thus, you are not missing anything. If the fitting is proper and was not cross threaded, the should be no leakage.
By the way, grease is not used in this place. You won't be able to find proper lubricant anymore. When I had finally used up my bucket (OEM) of leaf spring lubricant, I switched over to STP oil treatment.
Click to expand...
Yes the fitting is not cross threaded, that would be a bit hard to do. I do not have the fitting in front of me, but when examining the fitting and nut closely, it is easy to see there is no way the grease will be contained, and speaking of grease, I was informed that JT6 was an acceptable substitute in an earlier thread. Now, back to the lack of sealing, it would seem that if the fitting had a flange on it then it would seal against the outer periphery of the nut. As is, there is no way it will not leak. I will reach out to Michael at Third Gen for his input. Tomorrow I'll try to take a pic to show the problem, and maybe Pete could blow it up to further demonstrate.

Wrenching for 78 years,
 
I still wonder if you have the correct fitting. The correct fitting has a pipe thread, so it seals at the threads.
I am not aware of JT6 so can't comment on its feasibility. There is no doubt many chemicals that will work okay. Grease is not one.
 
Kube said:
I still wonder if you have the correct fitting. The correct fitting has a pipe thread, so it seals at the threads.
I am not aware of JT6 so can't comment on its feasibility. There is no doubt many chemicals that will work okay. Grease is not one.
Click to expand...
There is no way a grease fitting, pipe threads or not will seal when there are two slots the total length of the nut. I have demonstrated this by feeding a torch tip cleaner through this path. this is with the fitting really tight on the nut. Again, the fitting would need to have a flange between the threads and the hex on the fitting. See pic.
 

Attachments

  • 20250919_104249.jpg
    20250919_104249.jpg
    41.2 KB · Views: 269
Last edited:
TomC750 said:
There is no way a grease fitting, pipe threads or not will seal when there are two slots the total length of the nut. I have demonstrated this by feeding a torch tip cleaner through this path. this is with the fitting really tight on the nut. Again, the fitting would need to have a flange between the threads and the nut. See pic.
Click to expand...
573962
 
I have never, not even once, had an issue.
Perhaps the lubricant is taking the path of least resistance? IE your spring is clogged and won't allow the lubricant to flow properly.
If grease has been pumped in prior, it will clog rather quickly. Even the use of the proper lubricant dries and hardens through the past decades.
I have taken many NOS springs apart for my restorations and found each and every one was dried up and had to scrape the "stuff" out before bead blasting and powder finishing the individual leaf's.
 
You are correct. You have the wrong Zerk. Maybe place a washer under the Zerk to see if this will correct the leak of grease.
 
I agree with the others, wrong fitting. The ones pictured take a 1/2" wrench and they cover the slot on the nut.
 

Attachments

  • spr grease fit.jpg
    spr grease fit.jpg
    26.7 KB · Views: 206
  • spr grease fit 1.jpg
    spr grease fit 1.jpg
    22.8 KB · Views: 206
Kube said:
I have never, not even once, had an issue.
Perhaps the lubricant is taking the path of least resistance? IE your spring is clogged and won't allow the lubricant to flow properly.
If grease has been pumped in prior, it will clog rather quickly. Even the use of the proper lubricant dries and hardens through the past decades.
I have taken many NOS springs apart for my restorations and found each and every one was dried up and had to scrape the "stuff" out before bead blasting and powder finishing the individual leaf's.
Click to expand...
The path of least resistance is no resistance. The slightest pump on the gun (I am talking no more than an ounce of pressure) causes all kinds of grease to escape. I appreciate all your thoughts Kube.
 
Ahah Bob C, A picture is worth a thousand words isn't it! Thank you very much! And thanks to Pete too, there have been many cases where a larger photo helped me understand a situation.
 
Last edited:
The fitting on the center bolt is not for grease— that will clog the springs internal lubrication passages.
Spring lube is a thin oil (ice machine oil),talc with a very little ground asbestos according to Fords specifications.
75% automatic transmission oil 25% talc would be close,the service bulletins say to keep it i n a dedicated grease gun and to shake before using.
 
TomC750 said:
The path of least resistance is no resistance. The slightest pump on the gun (I am talking no more than an ounce of pressure) causes all kinds of grease to escape. I appreciate all your thoughts Kube.
Click to expand...

Wow! Then as others have said, a different fitting is needed. If you can't find one, let me know as I probably have them.
 
Kube said:
Wow! Then as others have said, a different fitting is needed. If you can't find one, let me know as I probably have them.
Click to expand...
Kube, Thanks for the offer, still waiting for response from Michael at third Gen, as I want him to be aware.
 
This problem has been all flattened out due to the generous donation of the correct grease fittings by a Ford Barn member. I shall not name the person, but a clue would be that his username starts with a "K".
I decided to use Lucas oil stabilizer as a lubricant. I took the car for a spin and I can't say it rides any different, but it rides so good anyway, it may be hard to tell on such a short jaunt. Thanks to all who helped with this.
 
You must log in or register to reply here.
Back
Top