grease zerk problems

[Lebneh]

So, a grease zerk on my loader broke off. I eventually got the broken piece out but not before I damaged the threads. I bought a replacement zerk and took it to Ace Hardware to find the proper size tap. The guy there recommended 1/4 -28 but did not have any. He said it might need to be tapered thread.


I was looking around on the internet and foudn this... Amazon.com: Irwin Tools 2623- 3 Piece High Carbon Steel - Tap 1/4" - 28 NF: Home Improvement


Do you guys think this will do the job? All suggestions are appreciated and a link to the item to buy would be a real big help.

Machine info:
John Deere 3720 with the 300CX Loader
Frontier AY11E - 72 In. 4-In-1 Bucket (the zerk is on the bucket)

 

[DJ54]

1/4" - 28 is the size. I think I got mine at NAPA...

 

[Lebneh]

DJ, thanks for the feed back, makes me feel a little better about it.

 

[Texan4Life]

1/4-28 and 1/8 NPT at the 2 most common i think. unless it is metric

 

[TBarD]

It is probably 1/4-28, however I think grease zerts use a tapered thread (NPT), whereas a NF tap is not tapered. You will need to remove the pin to dress up the threads.

 

[MHarryE]

Not sure what your loader is but there is a strong possibility there were no threads to mess up. Many companies use drive type zerks. All they need is a plain drilled hole, no threading (cost) or damaged threads (more cost). The zerk looks like a barb fitting for plastic pipe but on a much smaller scale. Check your hole diameter to make sure you have enough material to tap and fit a replacement or you will need to go oversize.

 

[PoorPlowboy]

Here's what I use...

GREASE ZERK TOOL FOR 1/4" FITTING - TOOLS AND ACCESSORIES

 

[DJ54]

I think I read the taper is 3/4" per foot. NAPA had at the time, a tap for grease zerks. Reasonable, so I bought two. Depending on how deep you boogered the threads, it may be tough to clean them all up with the pin still in there.

 

[Soundguy]

i use the same tools that poorplowboy linked to.. got mine at tractor supply.. they work fine.

remember.. if the hole is slightly od.. hit the open face with a hammer to shrink the hole...

 

[Lebneh]

I looked up the part number on JD's parts page. Here is the mystery part.
Looks like it's confirmed 1/4-28. I already bought a tool similar to the one suggested by PoorPlowboy (thanks for the link!).

The question is should I use that tool to fix the threads or just sink in "self-forming threads" zerk into the hole and hope for the best.

Thanks for all the input guys.. All suggestions are welcome and appreciated!

John Deere Grease Fitting - JD7844